Sciencescope - AEROSPACE by sdsdfqw21

VIEWS: 127 PAGES: 41

									ScienceScope
Quarterly publication of the CSIR                               Volume 1 Number 5 December 2006
South Africa's Council for Scientific and Industrial Research

www.csir.co.za




                                                   AEROSPACE
ScienceScope
Quarterly publication of the CSIR                               Volume 1 Number 5 December 2006
South Africa's Council for Scientific and Industrial Research

www.csir.co.za
         Volume 1 Number 5 December 2006


         IN THIS ISSUE...
AEROSPACE
Overview – Honing in on CSIR's role in aerospace ........................1

Persistent surveillance to protect our waters ..................................4

Proudly South African radar technology ........................................6

Predicting aircraft flight dynamics................................................8

Optimising aerofoils for best performance ....................................9

Research in support of flutter-free aircraft ....................................10

CSIR moves into civil aviation research ......................................11

Acumen in advanced aerospace materials ..................................12

Wind tunnel crown jewels essential for accurate data ..................14

Unique facilities give a competitive edge ....................................16

CSIR supports rockets and spacecraft ........................................18

CSIR imaging expertise propels SA to a science high ....................19

SA leads the way into space for a developing world ....................22

A space agency for South Africa – a holistic frame of reference ....26

CSIR gas turbine technology smartens up future aircraft ................30

Activities in light detection and ranging ......................................32



NEWS
Raising awareness about global water crisis ................................30

Safe drinking water from the sun ..............................................32

Biosciences ............................................................................34

Cereal crops improved without foreign genes ..............................36
                                                              SCIENCESCOPE DECEMBER 2006                      1
  South Africa has a long and proud history
  of aerospace innovation and development,
  with the CSIR being an inextricable part
  of this through its many years of novel
  aerospace research and development.




                    Honing in on
Overview
              CSIR’s role in aerospace
                      By Philip Haupt, Dr Kamalluddien Parker and John Wesley




             A
                        flourishing and competitive         fighter aircraft, or additional applications
                        aerospace industry is regarded      in other areas such as the automotive and
                        by most countries as an essen-      power generation industries.
             tial element for a secure and prosperous            Aerospace capabilities are essential
             nation. The European Union and America         to national safety and security. A large
             have extremely large aeronautical and          proportion of products in the aerospace
             space industries that are critical and         sector has direct defensive and offensive
             pervasive generators of technology,            applications, and is thus instrumental in
             wealth and expertise. By the very nature       maintaining sovereignty, force projection,
             of the skills and technologies involved,       peace keeping, as well as assistance in
             the world-wide aerospace industry is a         disaster relief.
             powerful driver of innovation across the            Internationally, extreme demands are
             industrial base.                               placed on the industry to achieve suitable
                   South Africa has a long and proud        levels of quality, safety, efficiency, certifi-
             history of aerospace innovation and            cation and R&D. Success in terms of these
             development, with the CSIR being an inex-      measures will not only position South
             tricable part of this through its many years   Africa’s aerospace manufacturing industry,
             of novel aerospace research and develop-       but also reinforce the role that local uni-
             ment (R&D). The CSIR is seen as a key          versities and science councils can play in
             player in the South African aerospace          creating the future technologies required.
             landscape and a custodian of unique                 The aerospace sector in South Africa
             world-class aerospace R&D skills.              consists of stakeholders in the general avi-
                   As incubator of all-encompassing         ation sector, commercial and military avia-
             technologies, outcomes of advances in the      tion. While the applications vary, the
             manufacture and operation of aerospace         underlying technology is inherently com-
             systems impact on society at large. This       mon to each of the sector components.
             could be in the improvement of the carry-      Any outward-orientated, nationally-focused
             ing capacity of commercial transport air-      intervention geared towards increasing
             craft, the avionics capabilities of military   the market share of the local industry in
2    SCIENCESCOPE DECEMBER 2006

    the global supply chain, should therefore             The two largest aerospace companies     relegating themselves to system integra-
    recognise that one of the optimal methods       in the world - Boeing and Airbus - control    tors. This allows a country like South
    of engagement is through the establish-         the largest share of both the civilian and    Africa to align with these needs. Any
    ment of technology platforms that can           military aerospace markets, either exclu-     potential tier supplier to these OEMs must
    impact on the entire aerospace sector.          sively or through mergers. Of the most sig-   therefore identify with and adapt to the
         The space component of aerospace           nificant market needs dictating their posi-   constraints of their tier group, as well as
    also relies to a large degree on similar        tion are requirements for on-time delivery    to the timescales of the OEM.
    basis technologies. These include               and technological advantage. Traditional            The opportunities created by the
    advanced light materials, high-resolution       military-focused aerospace companies -        drive towards system integration are
    sensors and advanced electronics. Of the        such as BAe, Dassault, SAAB and               being taken very seriously by the South
    26 technology areas designated by the           Eurocopter - also experience similar driv-    African government. It is striving, through
    European Space Agency, 18 are covered           ers in their markets given that the lines     relevant government departments, the
    to varying degrees within CSIR Defence,         between defence and civilian applications     CSIR and others, to ensure that all South
    Peace, Safety and Security, CSIR Material       are being removed and programmes are          Africans benefit from a sustainable, grow-
    Sciences and Manufacturing and the CSIR         being driven along technology lines only.     ing, empowered and internationally-recog-
    Satellite Applications Centre. CSIR Built       The A400M military transport aircraft is a    nised aerospace industry by 2014.
    Environment is also active in a sub-set of      typical example of this.                            Three government departments are
    the technology areas.                                 Alternatively, reduced time-to-market   actively involved with the CSIR in achiev-
         The nature of the technology is perva-     of an aircraft that has superior technology   ing this, namely the Department of
    sive and can, as such, be refined to fulfil     would provide significant market advan-       Defence (DoD), the Department of Science
    the harsh environmental parameters              tage. Thus, there is a coupling of the        and Technology (DST) and the Department
    required in both near and outer space.          needs of the original equipment manufac-      Trade and Industry (the dti). Each depart-
    Technologies focusing on the aerospace          turer (OEM) for novel technologies that       ment plays a unique, interlinked role with
    sector are also likely to find application in   characterise new aircraft, with the need to   the CSIR, who is the custodian on their
    the automotive and information and com-         integrate all components into a useable       behalf of relevant technology projects and
    munications technology (ICT) areas.             system quickly and efficiently. This will     programmes, such as the Advanced
Overview

                                                    provide customers with the competitive        Manufacturing Technologies Strategy
                         Below: Value chain         advantage they require in their aggressive    (AMTS) and the Aerospace Industry
                         from R&D to imple-         market or military application. Driven by     Support Initiative (AISI). This “value-chain”
                         mentation and              these and other needs, OEMs in the aero-      extends all the way from basic research to
                         dispersal to market        space sector have followed the example        actual usage.
                                                    of counterparts in the automotive sector in
                                                                                                 SCIENCESCOPE DECEMBER 2006
                                                                                                                                                        3
                                                                                                                             Enquiries:
                                                                                                                             Philip Haupt
                                                                                                                             Tel 012-841-2447




                                                                                                    Dr Kamalluddien Parker
                                                                                                                             Email phaupt@csir.co.za


                                                                                                                             Dr Kamalluddien Parker
                                                                                                                             Tel 012-841-2179
                                                                                                                             Email kparker@csir.co.za


                              Philip Haupt                                                                                   John Wesley
                                                                                                                             Tel 012-841-2068
            John Wesley
                                                                                                                             Email jwesley@csir.co.za




The technology validation and demonstra-       ply-chain optimisation, system integration      fluid mechanics, aerostructures, optoelec-
tion role is undertaken by the AMTS with       and optimisation, manufacturing infrastruc-     tronic sensors and systems, radar and
its focus on advanced manufacturing tech-      tural support and the management of             electronic systems. The DoD also supports
nologies, advanced product technologies,       large cardinal projects, such as the            the development of test and evaluation
ICT, logistics and advanced cleaner pro-       A400M military transport aircraft. Integral     technologies covering wind-tunnel testing,
duction technologies. These technologies       to this is the creation of relationships with   material and structural testing, aircraft per-
cut across the automotive, aerospace, tex-     the relevant international OEMs.                formance and handling test and evalua-
tile and clothing, metals, chemical and              The CSIR is uniquely placed to cover      tion, radar systems test and evaluation
cultural craft sectors. The areas of light     the technology overlaps between commer-         and optronic system test and evaluation.
materials include composites and light         cial aviation, space missions and military      Much of this is then used to develop dedi-
metals, such as titanium, magnesium and        operations. The DoD funds research in a         cated advanced test and evaluation facili-
aluminium. Light metals initiatives focus on   number of aerospace-related fields, such        ties in support of commercial and military
the reduction of aircraft structural weight    as aerothermodynamics, computational            industries.
and automobile weight, while increasing
local content.
                                                   Aerospace technology is a pervasive base that is key to the
      Another priority technology flagship
                                                   future. The DoD capabilities developed for aerospace are often
is advanced electronics, which include             used for other non-aerospace sectors of industry and society.
sensor development, technology and                 Examples include:
fusion. Sensors play an important role in          • Computational fluid dynamics is used extensively by the mining and metals
guidance and control systems for land,                industries
sea and air-based vehicles. Also included          • The structural vibration analysis method used for aircraft flutter prediction
in advanced electronics is miniaturisation            is applied successfully to large industrial plants
                                                   • Process modelling techniques develop for casting of turbine blades are
technology for gyroscopes and accelerom-
                                                      widely used to model casting processes in the automotive and metals
eters and in general micro-electro-mechan-
                                                      industries
ical systems.
                                                   • Materials and structural modelling techniques developed for turbine blade
      The technology advancement and                  design and life assessment is extensively used in the metals industry
product implementation role is undertaken          • Wind-tunnel testing supports renewable energy research by testing wind
by the AISI, which focuses on advance-                turbines
ment of technology developed through the           • Advanced aerostructures technologies have been used to establish South
AMTS and its partners, such as the CSIR,              African companies that became world leaders in advanced automotive
in the local manufacturing industry where             carbon fibre component◊
products need to be made correctly and             • Sub-system manufacture and aerothermodynamic capabilities are used to
efficiently. The AISI considers developing            develop advanced solar energy technologies.
technologies and processes around sup-

               • The South African Air Force is the second oldest in the world
 FA C T S




               • The Aeronautical Society of South Africa – established in 1911 –
                 is one of the oldest learned societies, promoting “the art and
                 science of aerial navigation”
     4   SCIENCESCOPE DECEMBER 2006
urveillance



                                      The Fynmeet instrumentation
                                      radar being used to meas-
                                      ure the radar characteristics
                                      of objects of interest in their
                                      natural environment as part
                                      of research into the auto-
                                      matic detection of these
                                      objects by means of radar
                                      sensors




                                      Small rigid inflatable boats
                                      (RIBs) are used for poach-
                                      ing, smuggling and even
                                      sometimes for piracy and
                                      terrorism
                                                                                                      SCIENCESCOPE DECEMBER 2006                         5
                                                                  regarding deployment of           sors; electro-optical sensors; radio frequency


Persistent
                                                                  forces to influence the situa-    surveillance sensors; and data fusion and
                                                                  tion become possible to           information extraction algorithms. In many of
                                                                  achieve the desired out-          these areas the CSIR and its partners at uni-

surveillance                                                      come optimally.                   versities and in industry have the required
                                                                                                    background and infrastructure. However,
                                                                  What is
to protect
                                                                                                    these need to be refocused and expanded to
                                                                  AwareNet?                         establish the new capability.


our waters                                                          The CSIR's plan to develop
                                                                    a science and technology
                                                                                                    Potential
                                                                                                    AwareNet users
                                                   (S&T) capability in line with international
       By Francois Anderson                        trends for persistent area surveillance has      It is planned that the AwareNet S&T capabil-
                                                   been dubbed AwareNet. Based on this              ity development be focused to support a spe-
                                                   capability (knowledge, facilities and            cific launch application, namely a maritime


S
           outh Africa and its surrounding
                                                   processes), solutions can be developed           area surveillance system, first for the coastal
            maritime zones are continuously
                                                   that will provide information derived from       regions of South Africa, then for the South
             being threatened by activities
                                                   real-time, persistent surveillance to users in   African Economic Exclusive Zone (EEZ) and
such as illegal fishing, illegal immigration,
                                                   the state's peace, safety and security relat-    later still for the extended South African EEZ
smuggling, piracy, terrorism and oil pollu-
                                                   ed agencies.                                     (which will include the rich fishing grounds
tion. In most cases, these activities are dif-
                                                          This information should allow users       of the Agulhas Plateau and Mozambique
ficult to observe, as these forces choose to
                                                   in these agencies to develop real-time situ-     ridge) and the southern African region.
work at night, in bad weather or in desert-
                                                   ational awareness regarding the presence                South African users who will benefit
ed places. The country has a 1,5-million
                                                   of entities in their areas of interest, their    from the AwareNet capability are the coun-
square kilometre economic exclusion
                                                   position and movement, their classification      try's peace-keeping forces, law enforcement
zone, but its naval and coast guard forces
                                                   and identity and their activities and inten-     agencies, environmental protection agencies
available for patrolling this vast area are
                                                   tions. Slowly changing information that          and disaster management agencies - the
relatively small considering the area to be
                                                   provides the context and thereby                 Department of Defence (South African Navy,
secured.
                                                   enhances the extraction of meaning from          South African Army, South African Force,
        Within the broader context of imper-
                                                   the sensed information will be seamlessly        Defence Intelligence and Joint Operations);
atives relating to the continent of Africa,
                                                   integrated with it. Examples include maps        the SA Police Service; the Department of
the New Programme for Africa’s
                                                   providing geographic and weather infor-          Transport; and the Department of
Development (NEPAD) identifies the estab-
                                                   mation.                                          Environmental Affairs and Tourism's Marine
lishment and maintenance of peace, safe-
                                                                                                    and Coastal Management. The information
ty and security as a prerequisites for sus-
                                                                                                    from the surveillance system will ultimately
tainable development in Africa. What               S&T required                                     enable these agencies to develop real-time
then can South Africa do to meet these
challenges? The modern international
                                                   for AwareNet                                     situational awareness regarding the pres-
                                                                                                    ence, position, movement, classification,
trend is to derive situational awareness
                                                   The AwareNet programme requires S&T              activities, intentions and threat levels of enti-
from persistent area surveillance sensors
                                                   capabilities and focused research and            ties of interest in their areas of responsibility.
that form part of a system of systems. The
                                                   development (R&D) in the systems, aero-                 In parallel with conceptualising and
  ultimate objectives of the high-level sys-
                                                   space, electronics and computer engineer-        developing technological solutions to a large
   tems are to provide real-time informa-
                                                   ing as well as in the information science        number of technical issues, researchers are
     tion with unprecedented richness and
                                                   and applied physics and mathematics              working with potential users to determine
       reach. The richness is achieved by
                                                   fields of knowledge. A substantial part of       and analyse their detailed requirements for
        tightly integrating a variety of new-
                                                   the required capability has been devel-          this type of system in order to fine-tune the
          generation, high-performance sen-
                                                   oped in South Africa over the past 30            solution for maximum impact.
           sors to form an information net-
                                                   years with military funding.across the                  Further impact may be achieved
            work, fusing the sensed data, and
                                                   complete value chain from academics              through support by the AwareNet S&T capa-
             extracting enriched information
                                                   through research institutions, test ranges,      bility for the development of persistent area
              regarding the situation. The
                                                   acquisition management, to industry and          surveillance products by the South African
                reach is achieved by segment-
                                                   some parts of the user community. The            Aerospace and Defence Related Industry.
                 ing the resulting information
                                                   proposed ultimate outcome of the                 This application of the capability may lead
                  into classes of interest for
                                                   AwareNet S&T capability development              to the establishment of a cluster of organisa-
                   various user groupings and
                                                   will go a long way to utilising this capa-       tions and a family of niche products that
                     providing only that part of
                                                   bility and converting it into a major new        could eventually contribute to South African
                      the real-time information
                                                   cluster fostering South African economic         international competitiveness.
                       that is of interest to
                                                   growth, job creation and international
                        each user group.
        Users may then develop the requisite
                                                   competitiveness in products required for           Enquiries:
                                                   national border surveillance and control.
situational awareness based on insight                                                                Francois Anderson
                                                   Five major areas of technology have been
into that part of the situation that is their                                                         Tel 012-841-2818
                                                   identified as underpinning a capability in
responsibility to control. Based on this                                                              Email: fanderson@csir.co.za
                                                   persistent area surveillance and remote
insight, predictions of how the situation
                                                   sensing: stratospheric airships; radar sen-
will develop and quality decision-making
6    SCIENCESCOPE DECEMBER 2006




                                                          Proudly South African

                                                                                   radar
                                                                                   technology    by Pieter Goosen




                                                                      South Africa's new Valour
                                                     class frigates are equipped with powerful
                               target trackers that were produced by local industry based on
                        tracking radar technology developed at the CSIR. They are capable
                       of tracking small targets at long ranges in all weather conditions and
                               form part of the ship's main weapon and air defence systems.



    R
             adar is a kind of remote sensor       reconnaissance and surveillance, air traf-    in developing and optimising a radar for
              that uses radio waves to detect,     fic control and navigation, space and         uniquely South African conditions.
              determine the direction, distance    range instrumentation and weather sens-       R&D opportunities are not limited to the
    and speed of objects such as aircraft,         ing radar systems.                            delivery of systems; the world-class nation-
    ships, terrain or rain, and map them. A              A radar competence was established      al capability in radar (consisiting of peo-
    transmitter emits radio waves, which are       in the CSIR in 1945 as part of the World      ple, know-how and facilities) can continu-
    reflected by the target and detected by a      War II effort and has since grown to          ously adapt systems to the changing sce-
    receiver, typically in the same location as    address South Africa's national needs.        narios and missions we face. This is made
    the transmitter. Although the radio signal     CSIR Defence, Peace, Safety and Security      possible through the programmable nature
    returned is usually very weak, radio sig-      contributes to the South African aerospace    of the radar. The key functions of a radar
    nals can be amplified easily. Radar can        industry through R&D in radar sensors and     are implemented in software deployed on
    thus detect objects at ranges where other      platform protection.                          custom-developed, high-performance digi-
    emission, such as sound or visible light,                                                    tal computing frameworks. The rapid
    would be too weak to detect them.              Radar R&D                                     advances in digital technology can be
    Modern digital signal and data processors      opportunities                                 utilised and continuously incorporated into
    allow information to be extracted from                                                       the systems, while more advanced and
    these reflections, enabling not only the       The South African Navy's new frigates are     sophisticated software can be developed
    detection of targets, but also sensing of      considered to be among the most               and integrated locally. New and better
    information regarding their positions,         advanced ships of their kind international-   functionality is constantly researched and
    movement, classification and identifica-       ly. The sensors are the eyes of the ship      developed utilising the MecORT and Test
    tion.                                          and the radar technology on board is          Target Generation (TTG) facilities on the
          The term “radar” was coined in           world-class. By developing the tracking       CSIR site in Pretoria. This technology is
    1941 as an acronym for “radio detection        radars in South Africa, R350 million was      transferred to Reutech Radar Systems, who
    and ranging”. This acronym, of American        kept in the country and provided the local    will maintain the operational systems and
    origin, replaced the previously used British   scientific and engineering community with     enable South African industry to compete
    abbreviation RDF (radio direction finding).    R&D opportunities. This enabled scientists    on the international sensor market.
    The functions and roles of radar include       and engineers to apply and grow their                Modelling and simulation environ-
    detection and search, target tracking,         knowledge through real-world experiences      ments are used during the conceptualisa-
                                                                                                SCIENCESCOPE DECEMBER 2006                   7
tion, design and testing phases of a             performance and functionality of radars       to work towards close collaboration on
radar. During development, high-fidelity         to, for instance, recognise an aircraft or    future radar-related research and develop-
hardware-in-the-loop simulation environ-         a ship. The Fynmeet mobile measurement        ment.
ments are used to validate and qualify the       facility, developed at the CSIR, can meas-           Radar and electronic warfare engi-
operation of hardware and software. The          ure these features uncer operational condi-   neers at the CSIR are currently directing
Enigma radar target and counter measure          tions. It has been procured by a number       their efforts at the Awarenet sensor, which
simulator is such a facility. Enigma stimu-      of international research institutes.         aims to watch over our national borders
lates the radar with radio frequency sig-               The knowledge and years of experi-     and increase the effectiveness of our secu-
nals that resemble the operational environ-      ence in tracking radar are also being         rity forces.
ment. It uses digital radio frequency mem-       applied in support of the acquisition pro-           The continued national investment
ory technology developed by the CSIR to          gramme of South Africa's new frontline        into radar research enables a growing
digitise, store, delay and modulate              fighter, the Gripen. The CSIR supported       number of scientific and technological
received radar pulses that mimic actual          the South African Air Force in pre-studies,   breakthroughs and creates industrial
reflections and emisions from targets such       requirement definitions, specifications and   opportunities, placing the CSIR and South
as aircraft, missiles or ships. This technolo-   evaluations of the fighter's multi-function   Africa at the forefront of new radar sens-
gy is world renowned and will soon be            radar. During the Gripen's life-time, the     ing capabilities.
manufactured under licence in the USA.           CSIR will play a key role in optimising the
                                                 application of the radars and self protec-
Fynmeet                                          tion systems and improving their capabili-      Enquiries:
                                                 ties. Through interactions with the suppli-     Pieter Goosen
Measurements in the field of the opera-          er, SAAB Microwave (previously Ericsson),       Tel 012-841-2060
tional environments and objects of interest      the quality of the CSIR's capabilities was      Email pgoosen@csir.co.za
allow the CSIR to continuously improve the       recognised and agreement was reached




The Enigma radar              The MecORT and
target and electronic                Test Target
attack simulator               Generator (inte-
developed by the                 grated on the
CSIR is used by                telecommunica-
several international      tions tower) on the
research and devel-          CSIR site are used
opment organisations          for research into
for radar research,             multi-path and
development, testing,         electronic protec-
evaluation and             tion, among others
operator training




                                                                                                                     South African Navy (SAN)
                                                                                                                     fregat fitted with the
                                                                                                                     uptronics and radar track-
                                                                                                                     er (Image by AB MJ
                                                                                                                     Pietbooi, SAN)
8    SCIENCESCOPE DECEMBER 2006




                                                                     Predicting
    T
            he prediction
            and analysis of
            air vehicle flight
    dynamics, as well as the eval-
                                                                    aircraft
    uation of the flying qualities of new
    aircraft is a specialist service rendered by
    the CSIR to the South African Air Force
                                                                flight dynamics
    (SAAF). The science of aerodynamics
    deals with the flow of air around aircraft                       By Dr Bennie Broughton
    and the resulting forces and
    movements/moments, while flight dynam-
    ics concentrate on the aircraft’s response      design control systems for the vehicles or            Flying qualities often include many
    to those forces. Flight dynamics therefore      to predict the exact motion of the vehicle     parameters that are very difficult to quanti-
    include the orientation and motion of an        through air. Wind-tunnel and computation-      fy, such as qualitative pilot ratings of the
    aircraft or other flight vehicle, as well as    al predictions can be used to test whether     aircraft handling or ride quality, and vari-
    the stability and control of that vehicle.      the release of a store from an aircraft will   ous measures to determine the safety of
           Closely related to the science of        be safe.                                       the aircraft from a handling point of view
    flight dynamics is an aircraft’s flying or            Current CSIR research is aimed at        throughout the flight envelope. Modern fly-
    handling qualities. One definition of flying    the development of a mini UAV that will        by-wire fighter aircraft, such as the new
    qualities states they are “those characteris-   be used to evaluate the effectiveness of       Gripen aircraft being accepted into the
    tics of an aircraft that govern the ease,       drag reduction on tailless configurations      SAAF, use computers that have full control
    precision and safety with which a pilot is      through reduced aerodynamic stability. To      over the aircraft. Pilot commands are inter-
    able to perform the required mission.”          make this unstable, unmanned aircraft          preted by the computers, which in turn
           The flight dynamics work at the CSIR     controllable, a complex control system is      decide on the correct deflections of the
    comprises not only the prediction of flight     being developed and implemented in col-        control surfaces to give the aircraft the
    dynamics of manned aircraft, but also of        laboration with the University of              desired response.
    other air vehicles such as missiles, guided     Stellenbosch. The successful implementa-              Due to the very high manoeuvrability
    and unguided munitions and unmanned             tion of this control system is highly          and performance of these aircraft and the
    aerial vehicles (UAV). The predicted stabil-    dependent on accurate prediction of the        complexity of the control systems, new dif-
    ity and control derivatives are used to         vehicle’s flight dynamics.                     ficulties arise, which are either not
                                                                                               SCIENCESCOPE DECEMBER 2006                9
encountered or of lesser importance for convention-
al aircraft. For example, a dynamic interaction
between the control system, the pilot (who are them-
selves a complex control system) and the dynamics
of the vehicle itself can lead to a phenomenon
                                                             Optimising aerofoils
called pilot- induced oscillations (PIO) – a danger-
ous motion of the aircraft that is difficult to arrest.
                                                             for best performance
       PIO tends to occur during the most dangerous
                                                             The cross-sectional shape of a wing has a sur-
and demanding phases of flight when precision of
control would normally be of the utmost impor-               prisingly large influence on an aircraft’s aero-
tance. The first prototype of the Gripen was lost            dynamic performance and efficiency. Intuition
due to a PIO during the final part of a landing
                                                             may suggest that thinner wings should pro-
approach. To prevent future occurrences of a han-
dling quality issue - such as a PIO - that can nega-         duce less drag than thick wings. However, the
tively impact on safety, it is often necessary to            dependency of a wing’s aerodynamic efficien-
reduce the performance of the aircraft. In order to
                                                             cy on the exact shape of the cross section is
find the optimum balance between performance
and safety, in-depth knowledge is required of flight         much more complicated than just the overall
dynamics, human factors and an understanding of              thickness of the wing.
what happens in the cockpit of the aircraft during
the different flight phases and missions.                    Before the Wright brothers built the first powered aircraft in 1903,
       Before the SAAF’s new Gripens can be hand-            they performed some of the world’s first wind-tunnel testing on different
ed over to the squadrons for operational use, it is          wing cross-sectional shapes, known as aerofoils. Since their early
necessary to evaluate all aspects of the aircraft’s fly-     work, thousands of different aerofoils have been designed in an
ing qualities. Although Gripens have been used by            attempt to produce the best for various types of aircraft. Traditionally,
the Swedish Air Force for many years, the opera-             engineers would select an aerofoil shape for a wing from a “cata-
tional tactics employed by the SAAF and the envi-            logue” of standard tested aerofoils with characteristics closest to those
ronment in which the aircraft will operate in South          required for the application in question.
Africa differ from those experienced in Sweden. It                  As aircraft designs became more refined and optimised for spe-
is therefore necessary to identify any safety or per-        cific roles, it became clear that one has to design a custom aerofoil for
formance issues before accepting the aircraft into           each specific application to get the best performance possible from a
operational use. The CSIR is closely involved in the         wing. In the past, many aerodynamicists saw aerofoil design as a
flying qualities component of the Gripen release to          “black art”, better left to a small number of peers who specialise only
service process.                                             in aerofoil design. However, modern computer technology and compu-
       Dr Bennie Broughton of the CSIR has worked            tational methods have made analysis and design of aerofoils much
closely with Gripen test pilots to develop a custom          easier and more efficient. Where design was often done on a trial-and-
reference flying quality specification for the Gripen.       error basis, it is now possible to design aerofoils using so-called
Although an excellent academic understanding of              inverse methods combined with numerical optimisation.
the issues is a minimum requirement for the work, it                The computational aerodynamics research group at CSIR
was also necessary to experience some of the prac-           Defence, Peace, Safety and Security has the skills and facilities to
tical issues relating to flying qualities and flight test-   design custom aerofoils for various uses, whether for manned aircraft,
ing. As part of his preparation, Broughton therefore         unmanned aerial vehicles or sometimes even wings that “fly” under
also attended the SAAF Operational Test and                  water. A recent application was to design the keel and rudder aero-
Evaluation course in the Western Cape earlier in             foils for the South African entry to the prestigious 2007 America’s Cup
2006 where he was exposed to actual flight opera-            Yacht Race. This design had particularly complex requirements, since
tions and testing in Cheetah fighter aircraft.               the yacht keel is required to function through a very wide range of
       The current flying qualities work on the Gripen       operating conditions – from reversed flow during the start of a race to
is expected to continue after the release to service         much higher speeds where the keel is required to generate side loads
process is complete. Each future update to the flight        of several tons. To design an optimum aerofoil for such a wide range
control system software of the aircraft by SAAB will         of operating conditions may seem like an almost impossible task, but
have some effect on the aircraft’s performance and           through the use of inverse design and mathematical optimisation, it
flying qualities. It will therefore be necessary to          was possible to use a computer program for generating and testing
evaluate it continually and track changes to the soft-       thousands of different shapes until one was found with the minimum
ware. Issues unique to South African conditions              amount of drag for each of the operating conditions as well as for a
may also only become apparent after operational              series of trim tab deflections.
testing and evaluation and actual in-service use.                   Currently, the CSIR is developing new methods for designing and
Communicating these issues to the original equip-            optimising two-dimensional aerofoil sections, as well as complex three-
ment manufacturer requires an in-depth knowledge             dimensional geometries. An example of one new method is a computer
of the system itself and the associated flight dynam-        program able to design and optimise simultaneously both the wing
ics theory. It is expected that the CSIR will continue       platform shape and the cross-sectional shapes to produce the most effi-
to be involved in this process throughout the service        cient wing for a specific application.
life of the aircraft.


              Enquiries:              Dr Bennie Broughton      Tel: 012 841 2109        Email: bbroughton@csir.co.za
10   SCIENCESCOPE DECEMBER 2006




       Research in support of
     flutter -free
        aircraft         By Dr Louw van Zyl




                                                                                             The CSIR is not only a specialist service

                                  F
                                          lutter is a potentially catastrophic,
                                          self-sustained oscillation of an aircraft   provider, but also develops its own systems
                                          in flight. Energy is transferred from       and software. A major recent project was
                                   the kinetic energy of the aircraft to vibra-       the development of a novel ground vibration
                                   tion energy through the interaction of elas-       testing system. The data processing algo-
                                   tic, inertia and aerodynamic forces. Once          rithms and user interface developed at the
                                   the flutter speed is exceeded, the smallest        CSIR are aimed specifically at sine-dwell test-
                                   vibration induced by turbulence, control           ing of aircraft structures. In this method, the
                                   inputs or engine vibrations will grow              aircraft - with its external stores attached - is
                                   exponentially until some non-linear effect         excited to vibrate in each of its natural
                                   alters the conditions necessary for the            modes in turn. This requires precise frequen-
                                   transfer of energy, or the structure fails.        cy control, force control and the correct bal-
                                           All new aircraft types must undergo        ance of forces. Dr Becker van Niekerk from
                                   a flutter clearance to ensure that it will not     Parsec Aero proposed using the CAN-bus
                                   encounter flutter within its intended operat-      architecture for the hardware implementation
                                   ing envelope. Military aircraft may be             and also supplied the hardware for the sys-
                                   required to carry external stores that were        tem. The CSIR's Erik Wegman was largely
                                   not envisaged or did not exist when the            responsible for bringing the ideas and hard-
                                   aircraft was initially cleared for flutter. A      ware together, resulting in a very capable,
                                   flutter clearance must therefore be under-         low-cost ground vibration test system.
                                   taken for each new external stores combi-                 The CSIR also developed systems for
                                   nation that the aircraft is required to            exciting the structural modes of an aircraft in
                                   carry.                                             flight for flutter flight testing, with separate
                                           The CSIR has been providing a flut-        systems for military and civilian applications.
                                   ter clearance service to the South African         The flutter flight test data analysis software
                                   Air Force (SAAF) since 1978; more than a           was developed over a number of years,
                                   100 flutter clearances have been complet-          mostly by CSIR researcher Stephan Viviers.
                                   ed successfully. The CSIR is responsible           Its strengths are fast turn-around and reliabili-
                                   for ground vibration testing, flutter analy-       ty under noisy conditions. The CSIR-devel-
                                   sis and flutter flight test data analysis. In      oped flutter analysis software includes
                                   recent years, the CSIR has also supported          unsteady subsonic, transonic and supersonic
                                   the local aeronautical industry with a full        aerodynamic codes.
                                   flutter clearance service. Aircraft cleared
                                   include the Ravin 4-seat touring aircraft
                                                                                        Enquiries:
                                   and the Slick 360 aerobatic aircraft. In
                                                                                        Dr Louw van Zyl
                                   addition, flutter flight testing was conduct-
                                                                                        Tel 012-841-2715
                                   ed for the Diamond aircraft company in
                                                                                        Email lvzyl@csir.co.za
                                   Austria and Grob Aerospace in Germany.
                                                                                               SCIENCESCOPE DECEMBER 2006          11

T
         he CSIR has embarked on an ini-
         tiative to build research capabili-
         ties in the civil aviation industry,      CSIR moves into civil
         with specific emphasis on the
African continent. Skills and capacity
developed in this much-neglected area of
                                                   aviation research
air transport are expected to contribute
significantly towards improving the indus-
try’s safety record and realising its poten-
tial as a catalyst for growth, both in South
Africa and the broader African continent.
       Civil aviation represents one of the
two major categories of flying, encom-
passing all non-military aviation, both pri-
vate and commercial. Under the Geneva
Convention of 1944, the aviation industry
is one of the most regulated industries
world-wide, with the International Civil
Aviation Organisation (ICAO) acting as
the industry’s governing body.
       The aviation industry research to be
undertaken by CSIR Built Environment
encompasses three main areas: institution-
al, technical and operational.
                                                                                                     by Bridget Ssamula

Challenges
and strategic                                                                                     Bridget Ssamula’s research

research needs                                                                                   involvement in aviation start-
                                                                                                 ed with the development of a
The institutional aspect of aviation encom-     and the International Air Transport
                                                                                                  cost model to run an airline
passes the bodies and institutions set up to    Association’s operational safety audits.
ensure the regulatory compliance and                   The operational aspects of the avia-        service along a route in a
alignment of each of the organs involved        tion industry are of vital importance, since        cost-effective manner, to
in the aviation industry. Institutions civil    the industry is characterised by high capi-
                                                                                                    meet existing passenger
aviation industries at country level and        tal costs, low profit margins, high competi-
regional organs such as the African             tion and, more recently, higher fuel costs           demand and allow for
Union, the New Partnership for Africa’s         and stringent safety and security systems.         appropriate aircraft choice
Development (NEPAD) and regional eco-           The aviation industry in Africa is crippled
                                                                                                  for the route. This work was
nomic communities, such as the Southern         by, among others, shortage of financing,
African Development Community (SADC).           the use of obsolete aircraft, insufficient         applied to her current PhD
       Research in this area is aimed at        skills and mismanagement.                         topic, ‘Cost effective strate-
identifying the setbacks and bottle-necks              Research in this area aims to estab-
                                                                                                   gies to design a hub-and-
that are hindering the liberalisation of        lish best practice in the aviation industry
African skies, and addressing the issues        by learning from countries, regions and            spoke network for sparse
that are holding back the globalisation of      airlines running profitable operations. In         travel demand in Africa’.
the region.                                     addition, independent strategies need to
                                                                                                  Ssamula is pursuing her PhD
       The technical component of the avia-     be developed particularly for the unique
tion research agenda focuses mainly on          African scenario, with its sparse, inelastic      at the University of Pretoria
the safety aspects of the industry. Safety in   passenger demand and high air travel              and as a visiting researcher
the African skies is a critical issue, with     costs. Tools such as logistics and opera-
                                                                                                  at the Institute of Transport
Africa’s rate of air accidents more than six    tional research and modelling can provide
times higher than the world average,            cost-effective route and network analysis         Studies at the University of
despite the fact that the continent carries     options, based on transport engineering           California Berkeley. The aim
only 4,5% of the world’s air traffic.           principles.
                                                                                                  of her thesis is to develop a
       The evaluation criteria for the black-          The ground-breaking research
listing process currently in place with the     described above ties in with the CSIR’s             hub-and-spoke network
ICAO and the European Union are detri-          key objectives of building research capa-        design to lower intra-African
mental to the already struggling industry.      bilities and transforming human capital.
                                                                                                  air travel costs, using logis-
The strategic needs in this research area
will focus on setting up regional agencies      Enquiries:                                       tics and operational research
and harmonising regulations, safety man-        Bridget Ssamula                                         methodologies.
agement systems and evaluation criteria to      Tel 012-841-4582
ensure compliance with ICAO standards           Email bssamula@csir.co.za
12    SCIENCESCOPE DECEMBER 2006




     Acumen in advanced
     aerospace materials
     By Philip Haupt and Dr Kamalluddien Parker




                                                                                                  the CSIR’s advanced vacuum-casting facili-
                                                                                                  ty. A technology consortium including uni-
                                                                                                  versities and industries, both locally and
                                                    aerospace, automotive and other high-         internationally, is involved in the project.
                                                    technology industries.                        The CSIR is also actively involved in titani-
                                                          The CSIR’s foundry has been             um high-performance machining studies as




     A
                dvanced materials are seen as       involved in high-technology aerospace         part of the AMTS’s titanium beneficiation
                the cornerstone of new and          castings for the past 18 years and has sig-   drive.
                improved aerospace systems          nificant experience in R&D relating to               The AMTS projects are geared
                and have for many decades           investment casting, process development       towards enhancing the competitiveness of
     been the key driver for the adoption of        and optimisation, and component qualifi-      local aerospace and automotive industries
     new aerospace technologies. This is appli-     cation. The foundry’s capabilities span       through technology advancement, in line
     cable to the design of both airframes and      across art-casting and jewellery-casting to   with the global trends of lighter and
     engines.                                       high- technology single-crystal (SC) blade-   stronger structures and components.
           Recent advances span not only the        casting. This facility has in the past               The facility is further involved in the
     materials but also related manufacturing       worked closely with Denel in developing       development of semi solid metal (SSM)
     technology. New materials, for instance,       components for the South African Air          processing of aluminium die-casting that
     are tailored according to the desired          Force (SAAF) and international players        currently receives funding from the DST.
     properties and manufacturability. A good       such as Snecma, Turbomeca, Superior Air              The foundry - together with support-
     example of this is work in investment cast-    in the USA, Rolls Royce in Germany and        ive technologies such as process model-
     ing of nickel-based superalloys for gas tur-   the United Kingdom. The facility has also     ling, rapid prototyping and structural
     bine engines, where the alloy needs to be      developed capabilities for SC casting         analysis - forms part of a supportive tech-
     tailored for manufacture as well as per-       technology for various engines, including     nology platform for the Advanced Metals
     formance.                                      the Russian RD33 and the Mig 29 fighter       Initiative (AMI). This initiative was
           Advances and areas of research in        aircraft, which have requirements for         launched in collaboration with Mintek and
     the CSIR centre around the following three     some of the highest technologies in the       Necsa in 2003. The Light Metals
     material types:                                casting industry.                             Development Network is a joint initiative
     ß advanced light metals                              One of the projects funded by the       between the CSIR, Mintek and Necsa as
     ß advanced composites                          Advanced Manufacturing Technology             part of the AMI and is coordinated by the
     ß natural/green materials.                     Strategy (AMTS), which is hosted by the       CSIR. The objective is to provide active
                                                    CSIR on behalf of the Department of           support for the growth and sustainability
                                                                                                  of an international downstream South
     Advanced                                       Science and Technology (DST), is to devel-
                                                    op advanced metals manufacturing tech-        African light metals industry.
     light metals                                   nologies for complex, thin-walled, light-            The CSIR is an active founder mem-
                                                    weight components using the investment        ber of the Rapid Product Development
     The CSIR is actively involved in the pro-      casting process.                              Association of South Africa, which looks
     cessing of aluminium, magnesium and tita-            Titanium casting development, in        at novel technologies for use in advanced
     nium for advanced applications in the          particular, is one of the main focuses of     manufacturing.
                                                                                                                                                13




                                                                                               Aerospace human
                                                                                               capital development
                                                 glass fibre reinforcement have wit-
                                                 nessed compounded growth of about             The need to develop skills in the aerospace
Advanced                                         7% in volume and value terms. This is         R&D environment specifically, and in the
                                                 attributed to their unique properties.
composites                                              The potential advantages of
                                                                                               aerospace sector in general, underpins the
                                                                                               CSIR’s technology advancement pro-
                                                 weight saving (light material), lower         grammes. Human resource management is
The CSIR has been involved in the develop-
                                                 raw material price from natural origin,       using the smart partnerships model tradition-
ment of novel composite material technolo-
                                                 and thermal recycling, or the ecologi-        ally applied to technology advancement. The
gies for the aerospace sector for the past 40
                                                 cal advantages of using resources that        CSIR engages with various people, through
years. Current activities deal primarily with
                                                 are renewable, contribute to the popu-        networks established by the AMTS, higher
smart structures and novel emerging materi-
                                                 larity of this material. The most impor-      educational institutes and further education
als.
                                                 tant of the natural fibres used in com-       and training to ensure that students are
       The smart structure technology focuses
                                                 posite materials are flax, hemp, jute,        exposed to the science of aerospace and
on adaptive structures that can change shape
                                                 kenaf and sisal, due to their properties,     have opportunities for financial assistance.
in response to their environment and specific
                                                 availability and good performance-to-         These efforts attempt to provide continuity in
operational requirements. The constituent
                                                 price ratio.                                  the need for specific research skills and the
components of the technology include the tai-
                                                        South Africa’s resurgence in the       curriculum followed at the institutions.
loring of composite laminates and the design
                                                 global automotive market and the inter-       Coupled to this is the programme to continu-
of actuators and sensors. One potential appli-
                                                 est of leading players in the aerospace       ously develop existing skills in the CSIR
cation is for aircraft wings without any con-
                                                 industries for sourcing natural fibre-rein-   through post-graduate study. The CSIR is
trol surface that geometrically morph on a
                                                 forced composite products and technol-        working with academic institutions by expos-
continuous basis in order to adapt to their
                                                 ogy from the country, sparked a project       ing students to the scientific method and
environment.
                                                 on natural fibre-reinforced composites.       allowing access to wind-tunnel test facilities
       Emerging materials under investigation
                                                 This project under the AMTS pro-              and experimental equipment, such as stereo-
include nano composites. These materials
                                                 gramme will address the research prob-        scopic particle image velocimetry for quanti-
incorporate nano diameter fibres embedded
                                                 lems and aims to fulfil in the need for       tative flow diagnostics.
in a conventional matrix. In the long term,
                                                 technical applications in structural and            On another level, in collaboration with
these materials will allow for enhanced per-
                                                 exterior components.                          the AMTS human capital development pro-
formance when compared to the current gen-
                                                        As one of the top four facilities in   gramme and the Automotive Industry
eration of materials. The underlying techno-
                                                 the world, the CSIR’s natural fibres cen-     Development Centre, students from universi-
logical advantage of nano composites as
                                                 tre in Port Elizabeth is involved in          ties are placed in an internship programme
applied to the aerospace sector, is increased
                                                 developing a natural fibre composite          at various companies over a period of 12
material performance against wear and dam-
                                                 material in conjunction with several          months. The students are exposed to technol-
age, improved structural strength-to-weight
                                                 academic institutions and industry part-      ogy challenges and ultimately gain experi-
ratios and improved surface finishes. This
                                                 ners. From a product perspective, the         ence in solving industry-specific problems.
technology allows manipulation and exploit-
                                                 objective is to produce a secondary
ing of material properties at metallurgical
level.
                                                 structure that conforms to stringent          Enquiries:
                                                 aerospace and automotive certification        Philip Haupt
                                                 requirements for fire, smoke and toxici-      Tel 012-841-2447
Natural/green                                    ty. It will also seek to develop fully        Email phaupt@csir.co.za
materials                                        renewable bio-composite materials in
                                                 line with the AMTS and scientific tech-       Dr Kamalluddien Parker
Over the past decade, natural fibre-rein-        nology plans of international aerospace       Tel 012-841-2179
forced polymeric composites that substitute      original equipment manufacturers.             Email kparker@csir.co.za
14    SCIENCESCOPE DECEMBER 2006




        Wind tunnel “crown jewels”
        essential for accurate data
           By Peter Bidgood




     Introduction                                    What do wind-       How they work
                                                     tunnel balances do?
     Major strides towards man’s first powered                                                        Internal wind-tunnel balances are, in
     flight were made between 1871, when             The primary aim of a wind-tunnel test            essence, lumps of material that have been
     the first wind tunnel was built and 1903,       is to obtain the loads imposed on a flight       shaped to produce measurable stresses at
     when the Wright brothers made their first       vehicle under varying environmental              specific points under specific loading con-
     powered flight at Kitty Hawk. These devel-      conditions. Thereafter, the science of           ditions, and no stress under any other
     opments were made possible largely by           scale modelling takes over. Using the            load conditions. The stress levels at these
     knowledge gained from wind-tunnel test-         load data obtained from an accurately            points are usually measured by means of
     ing. Even today, with parallel processing       scaled model in the wind tunnel, it is           strain gauges, which measure the local
     computers making in excess of 15 000            possible to predict the flight characteristics   material deformation. This deformation (or
     processors available, the use of computer       of the actual full-scale aircraft.               electrical output from the strain gauges) is
     modelling is still limited, particularly in            7The wind-tunnel balance provides         mapped to the applied load (calibration)
     modelling of phenomena that occur during        that data to an exacting level of accuracy       so that when in use, the load can be
     the change from sub-sonic to super-sonic        in the presence of large environmental           determined indirectly from the electrical
     speeds (i.e. in the speed ranges where          changes, such as temperature. In a               output of the strain gauges. The wind-tun-
     one changes from slower than the speed          fiercely competitive environment, wind           nel model is mounted on such a device to
     of sound to faster than the speed of            tunnels are largely characterised by the         determine any loads on the model. These
     sound). At these speed ranges, a fuzzy          quality of data they are able to produce.        balances are usually mounted inside the
     region exists where parts of the flight vehi-   It is not surprising that the balances           model and therefore referred to as internal
     cle may experience sub-sonic and other          developed and maintained at any specific         balances.
     parts experience supersonic conditions.         wind tunnel are often referred to as the                7The primary challenge in the pro-
     This is referred to as the trans-sonic region   “crown jewels” and are kept under lock           duction of these devices arises from the
     and is the primary test area for which the      and key, as this is often the underlying         fact that they have to measure six load
     medium-speed wind tunnel at the CSIR            technology base.                                 components simultaneously and accurate-
     was built.                                                                                       ly. In addition to this, two of these loads
                                                                                               SCIENCESCOPE DECEMBER 2006                   15
are usually very small in comparison to        • Micro Craft Technology (formally Allied      research and development and the building
the remaining four. To maintain the            Aerospace)                                     of several balances - all of which break with
required high levels of accuracy, the load     • Lockheed Martin                              currently accepted design philosophies - have
components are machined from single            • Institute for Aerospace Research             brought the wind tunnels to a point where they
pieces of maraging steel. The resulting        • Veridian (formally Calspan)                  can offer several cutting-edge balance tech-
design is usually not unlike a Chinese puz-    • Boeing                                       nologies.
zle. This creates a challenge for the          • AEDC                                               The latest balance produced by the
designer, the stress analyst as well as the                                                   CSIR’s medium-speed wind tunnel, called the
manufacturer. The designs usually require      Since then, there has been a significant       HARMS1, contains all the technologies pre-
substantial machining by means of spark        advance in balance technology. The             dicted to relevant by a panel of internationally
erosion, whereby the material is slowly        European community soon followed the           recognised experts from both Europe and the
eaten away by an electrical spark. This is     USA example and set about identifying key      USA in 1997, as well as some additional
a slow process; it is not uncommon for the     technologies that would be required to         technologies.
manufacture of a balance to take 12            obtain any significant advantage. The dan-
months to complete. A high degree of           ger of this was a potentially widening tech-   The future
confidence in the final design is required,    nology gap between the South African and
which is ensured, where possible, by finite    international wind tunnels.                    The process of research, it is said, has a
element analysis modelling. In the case of                                                    strong tendency to create more questions than
balances, this is not a simple process, par-   Latest CSIR                                    answers. This is undoubtedly true for the
ticularly if thermal modelling is included.                                                   research done over the past decade on inter-
                                               technologies                                   nal balances. Numerous avenues for contin-
Creating a common                              Recognising the trend in balance technolo-
                                                                                              ued development have opened up as a result
reference                                      gy, the CSIR’s medium-speed wind tunnel
                                                                                              of work done thus far. These include a collab-
                                                                                              orative research effort between the CSIR and
                                               set about characterising its balances and      Johannesburg University, aimed at the devel-
The escalating needs of the aeronautics        benchmarking them against data quoted          opment of fibre-optic balances. CSIR research
community in the mid-nineties led to the       from all available sources. A process of       into better sensors, design of experiment and
American Institute for Astronautics and
                                                                                              response surface methods, materials (including
Aeronautics recognising the need for
                                                                                              composites), electronics, data acquisition sys-
improving the performance of balances.
                                                                                              tems, automatic calibration as well as fully
Standards had to be created so that bal-
                                                                                              automated thermal calibration techniques, con-
ances from all the American tunnels could
                                                                                              tinues in a successful attempt to keep pace
be compared, thus having a common ref-
                                                                                              with international standards.
erence from which to advance.

Collaborators in this effort included:                                                        Enquiries:
• NASA Ames                                                                                   Peter Bidgood
• NASA Langly                                                                                     Tel: 012 841 4887
• NASA Lewis                                                                                         Email: pmbidgood@csir.co.za
• Northrop Grumman




Peter Bidgood is one
of the CSIR’s engineers
responsible for the devel-
opment and maintenance
of the highly sensitive
internal balance instru-
ments – the crown jewels
of wind tunnels testing.
16   SCIENCESCOPE DECEMBER 2006




                                                    Figure 5: In addition to the wind tunnel equip-
                                                    ment, the CSIR also has an extensive computation-
                                                    al fluid dynamics capability that extends into solv-
                                                    ing industrial flow problems. The capability is



       Unique
                                                    powered by a small cluster of computers and has
                                                    been used to do ground-breaking work on the
                                                    modelling of store release and unsteady helicopter



     facilities
                                                    flows used to optimise the self-protection suite of
                                                    the Rooivalk Attack Helicopter.




         give a
     competitive
             edge
                         By Dr Motodi Maserumule




                                                   Dr Motodi Maserumule
                                                                                               SCIENCESCOPE DECEMBER 2006                    17
                                            THE CSIR boasts the largest and best-            external aerodynamics in different flight
                                            equipped wind tunnel complex on the con-         regimes with numerical solution of the
                                            tinent. Seven wind tunnels and a water           governing equations of fluid motion. In
                                            tunnel, varying from the large 7m low            coming years, the group plans to be a
                                            speed wind tunnel to the smaller high            hub of expertise for computational aerody-
                                            speed wind tunnel, offer a test and evalu-       namics in South Africa.
                                            ation capability up to 4,5 times the speed             The Capital Renewal Programme,
                                            of sound. These facilities are backed by         funded by the Department of Science and
                                            world-class instrumentation and measure-         Technology (DST), is making a significant
                                            ment capabilities and a team of experts          contribution to maintaining the high stan-
                                            with experience that includes not only           dard of equipment and facilities.
                                            local aeronautical achievements relating
                                            to the Rooivalk, Umkhonto missile and            To date, the following capital renewal
                                            ACE trainer, but also international experi-      projects have been completed:
                                            ence on Eurofighter and Aermacchi.               • A new 1700cfm screw compressor for
                                                   The in-house design of internal bal-          the Mach 4,5 high speed wind tunnel,
                                            ances is one of the capabilities that makes          which doubled its productivity
                                            the CSIR’s wind tunnels uniquely competi-        • A high angle of attack (60º) and roll
                                            tive. Internal balances are used to obtain           scan capability high speed wind tun-
                                            the loads imposed on the flight vehicle              nel, enabling the testing of new gener-
                                            during wind tunnel testing, making it pos-           ation agile missiles
                                            sible to predict the flight characteristics of   • A vibration monitoring system for the
                                            the full-scale aircraft. The challenge is to         vital machinery of the premier transon-
                                            produce an instrument capable of absorb-             ic wind tunnel that helps to avoid
                                            ing the enormous stresses placed on a                expense or expensive? failures and
                                            wind tunnel model in one axis while tak-             plan maintenance activities
                                            ing precise, high-resolution measurements        • The refurbishment of a turbine test rig
                                            of all six load components (some of which        • An internal strain gauge balance
                                            are very small), and at the same time                repair, gauging and development lab-
                                            make them temperature independent. The               oratory to help maintain the develop-
                                            designs require a Chinese puzzle of com-             ment of world class balances
                                            ponents spark-eroded from a single piece         • An electronic pressure scanning sys-
                                            of maraging steel and can take as long as            tem, with sufficient portability to be
                                            12 months to complete.                               used in all of the tunnels, which signif-
                                                   These wind tunnels form an impor-             icantly enhances the pressure meas-
The recent addition of particle image       tant foundation for computational fluid              urement capability of the tunnel suite.
velocimetry equipment allows for quali-     dynamics (CFD). The Computational
tative laser sheet images such as this to   Aerodynamics Research Group focuses on           Strong links with the South African Air
become quantitative results                 the prediction and analysis of internal and      Force (SAAF) through the Test Flight and
                                                                                                          Development Centre has seen
                                                                                                          the CSIR develop the capabili-
Glen Snedden and Rhulani
                                                                                                          ty to support the flutter flight
Mathebule with the low-cost
turbine research facility that
                                                                                                          clearance envelope and store
has reaped instant reward in                                                                              configurations of all the
securing a place in a                                                                                     SAAF’s supersonic fighter air-
European Union Framework 6                                                                                craft via unique ground vibra-
aerospace project called                                                                                  tion test equipment, flight
VITAL.
                                                                                                          clearance software and flutter
                                                                                                          excitation hardware.

                                                                                                          Enquiries:
                                                                                                          Dr Motodi Maserumule
                                                                                                          Tel: 012 841 4229
                                                                                                          Email:
                                                                                                          mmaserumule@csir.co.za
18    SCIENCESCOPE DECEMBER 2006




       CSIR supports                                                                                     I can't open this tiff?

       rockets and                                                                                       please email again.


       spacecraft


                                                                                                     The photograph depicts the Ka band
                                                                                                     antenna used for TT&C services. South
                                                                                                     Africa is one of two countries in the
                                                                                                     world that operates a TT&C Ka band
                                                                                                     antenna. Ka band technology is very
                                                                                                     complex due to the high frequencies,
                                                                                                     short wavelength and rather narrow
                                                                                                     beams.

                                                                                                     Table of available TT&C frequency bands

                                    By Wabile Motswasele                                                RF BAND     FREQUENCY RANGE



 TT&C              , a commonly used acronym                 The primary technology base for                L             1-2 GHz
                   in the aerospace industry,         TT&C systems is rather similar to satellite
                                                                                                            S             2-4 GHz
 stands for telemetry, tracking and command-          telecommunications services. A useful
 ing. In the context of the operations of the         analogy would be to consider TT&C serv-               C             4-8 GHz
 CSIR Satellite Applications Centre, this             ice provisioning as the back-office opera-            X            8-12 GHz
 includes support to rocket launches, space-          tions and satellite telecommunications
                                                                                                           Ku           12-18 GHz
 craft launches and spacecraft operations. The        service provisioning as the front-office.
 CSIR renders a wide range of TT&C services                  The outdoor antenna infrastructure            Ka           26-40 GHz
 to a diverse customer base located primarily         includes the parabolic reflector, the anten-
 in the USA and Europe. The centre operates           na drive systems and the electronics sub-
                                                                                                     The significance of such a wide RF band
 and maintains a number of antenna systems,           systems. The indoor equipment consists of
                                                                                                     is that, considering South Africa’s strategic
 each optimally designed and adapted for              the processing and operations systems.
                                                                                                     geographical location, it allows the CSIR
 specific TT&C service offerings. Thus each           The interface cables between the indoor
                                                                                                     flexibility in accommodating ever-increas-
 antenna can be considered a product with             and outdoor are a crucial component of
                                                                                                     ing complex sets of user requirements
 specific features to support specific customer       the architecture. With recent advances in
                                                                                                     from a wide range of existing and poten-
 requirements. With the same infrastructure,          optical fibre technology, links made of
                                                                                                     tial clients.
 the centre also provides satellite tracking and      optical fibre present major advantages
                                                                                                            Less apparent is the fact that TT&C
 data acquisition (ST&DA) services. These             over coaxial-based cables. Improved effi-
                                                                                                     services are - by virtue of the requirement
 services are geared for receiving satellite          ciencies are achieved in terms of signal-to-
                                                                                                     to transmit signals from ground to space -
 imagery from a wide but select range of              loss ratio and minimised damage as a
                                                                                                     subject to the telecommunications regulato-
 remote sensing satellites orbiting in space.         result of lightning strikes.
                                                                                                     ry framework. Therefore, each TT&C
        Tracking involves the capability of a                The CSIR’s service offerings involve
                                                                                                     capable antenna at the CSIR is licensed
 ground-based antenna to locate accurately,           the following in terms of support for a
                                                                                                     by the Independent Communications
 lock and track a spacecraft as it orbits in          rocket or spacecraft:
                                                                                                     Authority of South Africa (ICASA) for per-
 space.                                               • Low earth orbit phase
                                                                                                     mission to transmit RF signals. This process
        Telemetry refers to the activity of receiv-   • Transfer orbit phase
                                                                                                     ensures that the CSIR can perform its
 ing data from a spacecraft. The data are             • In-orbit testing
                                                                                                     TT&C services reliably without interference
 processed by complex ground-based systems            • Life cycle support
                                                                                                     from other users.
 for the distinct purpose of displaying space-        • Emergency support.
 craft operating conditions on screen and ter-
 minals.                                              These services are executed with a com-        Enquiries:
        Commanding relates to transmitting            prehensive antenna product portfolio rang-     Wabile Motswasele
 data from ground-based antennas to the               ing in a wide selection of radio frequency     Tel 012-334-5005
 space craft.                                         (RF) bands:                                    Email wmotswasele@csir.co.za
                                                     SCIENCESCOPE DECEMBER 2006   19

                                     Lee Annamalai




           CSIR imaging expertise
           propels SA to a science high
              By Dr Bob Scholes and Lee Annamalai




The first “made in South Africa” satellite, called SunSat,
was designed and assembled at the University of Stellenbosch
and launched by NASA in 1999. The main instrument it
carried was a four-band visible and near-infrared high-
resolution imager designed and built by the electro-optics
group of the CSIR. The innovative optical design of the
imager centred on sensor elements attached directly to the
surfaces of a cubic prism, thus making the assembly extremely
robust to the vibrations associated with satellite launch.
20    SCIENCESCOPE DECEMBER 2006




     S
               ubsequently, the University of       cy and economies of scale. The sensor             weight and provides the power and versa-
               Stellenbosch formed a company        therefore needed to be light, compact and         tility of having information from several
               called SunSpace to nurture and       multi-purpose.                                    different types of sensors, while avoiding
               exploit the skills that had been            The CSIR was part of the MSMI con-         the problems of aligning and coordinating
     developed during the SunSat project.           sortium. It provided one of the initial opti-     images taken from different telescopes or
     SunSpace has since manufactured entire         cal designs (not the one that was finally         over different satellites.
     satellites and subsystems for various inter-   chosen), developed the specifications for                 The principle sensor is a high resolu-
     national clients, with the CSIR providing      the image products, and developed a test          tion multispectral “pushbroom” device
     optical design, test and evaluation support    application for the data which the MSMI           with six user-specified bands in the 400 to
     in most of these projects. One of              will provide. The CSIR’s optronic sensor          1 000 nm wavelength range, which cov-
     SunSpace’s early sales was a SunSat-type       systems group still played an advisory role       ers the visible and near-infrared region.
     imager, also built at the CSIR, which was      to the project team on design-reviews and         The linear sensor elements can cover a
     carried on board a Korean microsatellite,      the precision electro-optical test, while the     path (a “swathe”) 27,6 km wide with pix-
     KITSAT.                                        evaluation laboratory performed the test          els 4,6 m wide. Each is fitted with an indi-
            The next step in the development of     and evaluation of the imager to ensure            vidual filter that lets through only a
     a South African satellite programme was        conformance to specifications. The test           defined set of wavelengths. The CSIR ran
     a three-year Innovation Fund project           and evaluation laboratory performed               a comprehensive process to recommend
     called the Multi-Sensor Microsatellite         vignetting and flat-field tests on the imag-      which bands should be selected for the
     Imager (MSMI), which began in July             er, while radiometric calibration was a           versions of the MSMI to be carried on the
     2003. Its objective was to design, build       responsibility shared between the optron-         South African satellites (Table 1).
     and bench-test an imager for use in a          ics sensor systems group and the CSIR                     Next to the multispectral sensor is a
     series of low-earth orbit earth observation    National Metrology Laboratory. These              panchromatic (black-and-white) pushb-
     microsatellites - a microsatellite has a       tests essentially ensure that the optical tele-   room sensor with twice the resolution (2,7
     mass less than 500 kg (about 150 kg is         scope and detector are performing at the          m ground sampling distance), a 23,6 km
     more typical). These small satellites are      optimum in order to capture the best data         swathe, and an outstanding signal-to-noise
     much cheaper to build and launch com-          when the satellite is in orbit.                   ratio. One of its main uses is pixel sharp-
     pared to the one-to-10 tonne space plat-              The MSMI family is quite unusual in        ening, a technique that effectively
     forms - the current workhorses of earth        that several sensors share the same focal         improves the resolution of the multispectral
     observation. As a result, many more can        plane, and thus all look at the earth             sensor to the 2,7 m range. In addition
     be built, providing operational redundan-      through the same telescope. This saves on         there is a second panchromatic sensor:

     The bands that have been selected for the MSMI on the first two South African satellites.



       Band                 Description
       (nm)

       BLU 440-510          Blue wavelengths are often left out, because the dust in the atmosphere makes them
                            turbid. That is why it is put in – knowing the amount of aerosols allows the image to
                            be corrected for dust in other wavebands. It is also good for seeing through shallow
                            coastal water and for providing the blue in true colour images.

       XAN 520-540          This is an experimental band that coincides with absorption by the secondary
                            photosynthetic pigment xanthophyll. It is hoped that it will provide information
                            about stress in plants.

       GRN 520-590          This band provides the green in true colour images. The yellows and greens can be split
                            by subtracting the XAN band from GRN.

       RED 620-680          Apart from providing the red in true colour images, this band coincides with the main
                            absorption by chlorophyll.
                            This is a heritage band, widely used on earth observation satellites as part of
                            vegetation indices.

       REI 690-730          When plants are under stress, such as from drought, their absorption spectrum shifts
                            in this red edge zone.

       NIR 840-890          Green vegetation reflects most of the radiation that falls on them in the near-infrared.
                            Therefore this band provides a good reference band for normalising vegetation indices.
                            It is a heritage band that goes with the red band.
                                                                                                SCIENCESCOPE DECEMBER 2006                    21
                                     Dr Bob Scholes




                                                                                               hyperspectral processing to detect alien
                                                                                               and invasive vegetation. These compe-
                                                                                               tences will be used to support and process
                                                                                               data collected from the South African
                                                                                               micro-satellites and support the range of
                                                                                               activities that these satellites are envis-
                                                                                               aged for.
                                                                                                      The unique capabilities of the MSMI
                                                                                               package will be tested to the limit by an
                                                                                               application designed in a collaborative
                                                                                               effort between the CSIR and the
                                                                                               Agricultural Research Council. The appli-
                                                                                               cation aims to improve the quality of fore-
                                                                                               casts of food security in Africa.
                                                                                                      Famine and droughts affect millions
                                                                                               of people in Africa and billions of dollars
                                                                                               are spent every year trying to mitigate
two-dimensional with the ability to take         data the Sumbandila will be generating.       their effects. The food security application
snapshots like an ordinary digital camera.              It is envisaged that the yet-to-be-    sets out to integrate information to be pro-
It therefore preserves the precise spatial       named ZASat-003 will be launched a            vided by MSMI on the area planted with
relationships between the image elements,        year after ZASat002’s departure into          crops, the types of crop and their project-
and is intended for use in object identifi-      space. It will carry the full MSMI instru-    ed yield at harvest, with social and eco-
cation using pattern recognition. Each           ment, as well as a hyperspectral imager       nomic data about demand, supply and
snapshot covers a 3,3 x 2 km area in             designed and built by Flemish collabora-      affordability of food. The aim is to reveal
2,6m pixels.                                     tors. The hyperspectral imager shares the     the locations of food shortages, at local
       The first satellite scheduled to carry    same telescope and has a 14,9 km              government level, several months before
an MSMI, the Sumbandila, (which has the          swathe with 14,5 m ground sampling dis-       they occur and thereby direct the interven-
serial number ZASat-002), is due for             tance. It slices up the spectrum between      tions more accurately.
launch in May 2007 aboard a Russian              400 and 2 350 nm into 200 bands, each
submarine. This will be a pathfinder mis-        10 nm wide. It will be used mainly for        Enquiries:
sion to test the technology - the telescope      detecting crop diseases and stresses, as      Dr Bob Scholes
is slightly smaller than the one to be car-      well as for prospecting new mineral           CSIR National Resources and the
ried with the normal MSMI package, and           deposits.                                     Environment
the ground sampling distance of the multi-              The CSIR is actively building its      Tel: 012 841 2045
spectral sensors is therefore 6,5 m (with a      research capacity in hyperspectral analy-     Email: bscholes@csir.co.za
swathe of 40 km). The CSIR Satellite             sis so as to be able to use this new tool
Applications Centre, through its tracking,       effectively. A key initiative in hyperspec-   Lee Annamalai
telemetry and command capability, will be        tral image processing has been an inter-      CSIR Defence, Peace, Safety and
responsible for communication with the           national collaboration and exchange pro-      Security
satellite once it is airborne. The centre will   gramme between the CSIR and VITO (the         Tel: 012 841 3039
also be responsible for downloading the          Flemish institute of technology), to use      Email: lannamalai@csir.co.za
22    SCIENCESCOPE DECEMBER 2006




     South Africa leads the way into
     A simulation of the various swathes cre-
     ated by the four sensors in the MSMI
     package that are to be carried on
     board the ZASat-003




                                                South Africa will launch its own
                                                low-earth orbiting microsatellite,
                                                Sumbandila, abroad a Russian
                                                submarine near Murmansk on
                                                the Barents Sea. It’s the first
                                                of a series of national satellite
                                                developments that will give
                                                South Africa more affordable
     The
     assembled
     SunSat (ZASat-001)
                                                access to space technology
     on its handling trol-
     ley, prior to launch.                      and data.
                                                                                                   SCIENCESCOPE DECEMBER 2006                    23




space for developing world


                                                            By Dr Bob Scholes, Professor Arnold Schoonwinkel and Hendrik Burger

                                                 Scholes is a systems ecologist at the CSIR,
                                                 Schoonwinkel is Dean of Engineering at the University of Stellenbosch and
                                                 Burger is project engineer at SunSpace Ltd.




  T
          he name Sumbandila, meaning            economies from low-value farming and             viation. If MSMI can be improved, even if
          “lead the way'”in Tshivenda, was       mining economies to sophisticated service        only by a few per cent, the reliability of
           selected as the winner in the         and manufacturing economies that offer           information about who needs what food
  "name the satellite challenge" that was        higher growth rates and better jobs. These       and when, the savings on loss of life and
  open to all South African school learners      countries already have active space pro-         resource wastage will easily pay for the
  in grades 7-12.                                grammes. Two African countries (Algeria          cost of the satellite. Many other satellites
         7Although the country’s work on         and Nigeria) recently purchased satellites       in space can (and do) help, but none
  satellites is relatively new, it has been      from the developed world – South Africa          have the unique combination of wave-
  marked by remarkable success. In               believes that building our own grows our         bands and image detail needed to moni-
  February 1999 a NASA rocket carried            capacity far more effectively.                   tor crop development in smallholder fields
  SunSat – a microsatellite designed and                The task of designing and satellites,     in Africa. As a scientific bonus, the full
  built at the University of Stellenbosch –      together with the data-processing software       MSMI package that will be carried on
  into orbit. This pioneer survived in the       and supporting ground stations, raises the       Sumbandila will include a hyperspectral
  space environment for nearly two years,        competitive standards across the fields of       sensor that slices the visible and infrared
  beaming back images of the earth’s sur-        technology and manufacturing. Advanced           spectrum into over 200 narrow bands,
  face and testing several innovative aero-      capacity in materials science, electro-          providing a unique “spectral signature”
  space technologies. SunSat was one of a        mechanical design, communications,               for different types of land surface. By
  handful of satellites ever launched that       optics, data-handling, precision manufac-        measuring the precise absorption bands
  were designed and built by university stu-     ture, and testing and systems is required.       of particular molecules, hyperspectral sen-
  dents. And its launch made South Africa        These high-tech developments have appli-         sors can provide information about crop
  one of a small group of nations with the       cations in many other spheres. South             health, nitrogen content, soil type and
  capacity to build and operate space plat-      Africa has already notched up significant        mineral resources.
  forms.                                         sales in the competitive domain of space-               Weed control is another example of
                                                 related hardware and created a small but         the way MSMI sensors can be applied.
                                                 competent industrial sector. Most impor-         The South African government spends hun-
  Why a space                                    tant, a space programme develops,                dreds of millions of rands each year com-
  programme for                                  retains and attracts skilled and talented        bating water-wasting alien vegetation so
  a developing                                   people for the country.                          as to increase the flow in our rivers2. If
                                                        The satellites will provide great earth   the MSMI can direct this investment more
  country?                                       observation benefits. The Multi-Sensor           precisely, the benefits can be greatly
                                                 Microsatellite Imager (MSMI) package to          improved.
  The “space race” has its origins in nation-
                                                 be carried by South Africa’s satellites was             A third example involves urban serv-
  al pride. Beyond nation-building, howev-
                                                 designed to improve food security in             ice delivery. Like most developing coun-
  er, space programmes have strategic
                                                 Africa, but meeting the observation speci-       tries, South Africa is urbanising rapidly.
  value as well as industrial spin-offs. South
                                                 fications for this challenging task also has     The MSMI can help to map and classify
  Africa, with countries such as China, India
                                                 the potential to achieve much more.              informal settlements and help direct servic-
  and Brazil, belong to a small group of
                                                        African and donor nations spend           es to where they are needed.
  developing nations endeavouring to mas-
                                                 over a billion rands a year on hunger alle-
  ter technologies required to leapfrog their
24     SCIENCESCOPE DECEMBER 2006

           A computer-aided design image of           Depending on the width of the strip observed         together – and to fit into the microsatellite
             the ZASat 003 satellite, carrying        (the swathe), it can be days or months before        mass and volume restrictions. They have
               the full MSMI sensor package.          they pass directly over the same scene again.        to work flawlessly, despite the violent
                                                      This period is called the revisit interval. In       shaking of the launch and the hostile
                                                      practice, the revisit interval must also take        environment of space. So they need a
                                                      into account the possibility that the scene will     rigid chassis made of light, strong materi-
                                                      sometimes be obscured by clouds.                     als and much careful design and testing.
                                                                                                                  The prototypes begin as three-
                                                               Satellites that must stay exactly in        dimensional drawings and computer
                                                                one place in the sky have to occupy        models. Then physical models are built,
                                                                a very special geostationary orbit.        to exacting standards, with the right mass
                                                                This is an equatorial orbit (going         and shape. The components are baked,
                                                                around the middle of the earth             irradiated and shaken to the point of fail-
                                                                rather than over its axis) at approxi-     ure – first individually, then together –
                                                                mately 36 000 km above the                 and redesigned if necessary. [Figure 4
                                                                ground. Since there is only one            here] Then an exact duplicate of the
                                                                such orbit, and it’s in high demand        satellite is built and exposed to rigorous
                                                                for telecommunications and weather         tests that mimic launch and space condi-
                                                                satellites, the “parking spaces” in        tions. Once it passes all the tests, the
                                                                the geostationary orbit are strictly       actual satellite is built and packaged for
                                                                regulated.                                 shipping to the launch site.

                                                                Select a sensor                            Design and build the
                                                                system                                     ground sector
                                                                  Different features on the earth’s sur-   A satellite in space is no use if one can’t
                                                                  face vary in size and spectral           communicate with it or use the data it
     Recipe for a satellite                           reflectance or radiance (colour 3). Different
                                                      sorts of sensor are needed to detect this
                                                                                                           provides, so a ground sector must be
                                                                                                           built. The elements that stay behind on
                                                      returning electromagnetic radiation. The visi-       earth – the antennae, control systems,
     Decide what you need it for                      ble and near-infrared part of the spectrum           data processing hardware and software,
     Designing a satellite involves a series of       can be covered using cheap, robust and sen-          image delivery systems and applications
     compromises: decisions need to be based          sitive silicon charge-coupled devices (CCDs).        developed for the data – are typically as
     on mass, cost, reliability, and various per-     The longer wavelengths need more exotic              expensive to build as the space hard-
     formance characteristics. Sometimes differ-      detectors.                                           ware itself. Fortunately, South Africa has
     ent applications have similar requirements              Most satellites do not form an image by       certain infrastructure in place. This
     in terms of the wavelengths in which they        taking a two-dimensional snapshot like a digi-       includes the CSIR Satellite Applications
     observe the size of the objects they need        tal camera. Instead, they use the forward            Centre that will be responsible for opera-
     to be able to see, and the frequency with        motion of the satellite to scan along the scene      tions, telemetry, tracking, control as well
     which they need to see them – however            using a one-dimensional array of sensors,            as data capturing when Sumbandila is
     this is not always the case. So it’s crucial     rather like a scanner. The advantage of              launched. Other partners in this
     to decide, first of all, what the satellite is   microsatellites is that they’re relatively easy to   Department of Science and Technology-
     needed for, and then to work out the             point side to side to see something that does        developed project include the University
     design specifications for satisfying those       not lie directly below the satellite path. The       of Stellenbosch, Sunspace and
     needs.                                           same inertial control system can be used to          Information Systems. The University of
                                                      “nod” the sensor along the path, so that it          Stellenbosch is responsible for managing
     Select an orbit                                  dwells on a scene for a longer time, thus cap-       the project and training students, while
     “Space” begins about 100 km above the            turing more light. This feature becomes impor-       Sunspace and Information Systems are
     earth. The higher the orbit, the more            tant if you’re looking at tiny objects within a      tasked with building the satellite.
     expensive it is to launch the satellite. But     narrow wavelength band.                                     The task also includes raising user
     orbits lower than 1 000 km experience a                 The type of sensor and the quality of         awareness, training new operators and
     small drag caused by the remnants of the         the optics control the resolution (the smallest      preparing everyone for the deluge of
     atmosphere. Unless it carries “booster”          detail detectable on the focal plane). The tel-      information when it comes.
     fuel, the satellite gradually slows down         escope focusing on the image, together with
     and drops out of orbit.
     The higher the orbit, the harder it is to see
                                                      the altitude of the orbit, then determines how       The sky is the limit
                                                      big an object this becomes when translated
     small objects on the earth’s surface.            into its size on the ground the ground sam-          The South African Space Agency (SASA)
     Therefore, earth observing satellites typi-      pling distance). The swathe width is deter-          was formed in July 2006, while a space
     cally occupy low earth orbits (LEO) some         mined by the number of sensors once can              council has also been formed to decide
     500–900 km up, which means they make             pack across the focal plane. If one wants to         on space policy. In addition, South Africa
     one complete circuit around the earth            see small objects on the ground, the swathe          will chair the prestigious international
     about every 90 minutes. During this time,        needs to be narrow.                                  Committee of Earth Observation Satellites
     the earth rotates beneath them (assuming
                                                                                                           (CEOS) in 2007 and will join the exclu-
     that they are in a polar orbit, which takes      Fit the package together                             sive club of nations operating their own
     them more or less over the north and             The sensors, optics and systems for control,         satellites.
     south poles), and they see a different part      navigation, data storage, communication and
     of the globe on their next pass.                 power supply all need to work seamlessly
                                                                                                                                  SCIENCESCOPE DECEMBER 2006                25
           Satellites come in different sizes
According to broadly-accepted convention, satellites are classified                                                  The past two decades
as follows:
                                                                                                                     of SA’s space history
      >500 kg             satellite (this type includes most communication,
                          weather and earth observation satellites)                                                  1991–1999 A group of engineering students at
                                                                                                                                   the University of Stellenbosch, led by
     10–500 kg            microsatellite (includes many of the research                                                            Garth Milne, Arnold Schoonwinkel,
                          satellites in space)                                                                                     Jan du Plessis, and Sias Mostert,
                                                                                                                                   decided to design a microsatellite as
      1–10 kg             nanosatellite (currently under development)
                                                                                                                                   a collective project.
       >1 kg              picosatellite (no well-known ones yet)
                                                                                                                                   Microsatellites are quicker to design,
In practice, launch opportunities are defined as much by the volume                                                                cheaper to build and launch and
occupied by the satellite as by its mass. Sumbandila must fit into a                                                               more agile in space than convention-
box with dimensions 600x600x800 mm. The solar panels and the
                                                                                                                                   al satellites weighing several tonnes.
telescope baffles unfold once safely in orbit in space
                                                                                                                                   SunSat was built on a remarkably
                                                                                                                                   low shoestring budget in the
 The South African satellite platforms                                                                                             University’s Department of Electrical
                                                                                                                                   and Electronic Engineering, with
                           ZASat-001                        ZASat-002                     ZASat-003                                optics designed and manufactured
                           (SunSat)                         (Sumbandila)                                                           by the CSIR [Fig 1 near here].
                                                                                                                                   SunSat used off-the-shelf electronic
 Launch date               23 Feb 1999                      December 2006                 December 2007                            components as far as possible rather
 and place                 Vandeberg Air                    Barent Sea,                   Barent Sea,                              than the very expensive custom-
                           Force Base,                      Russia                        Russia                                   made, space-certified hardware typi-
                           California USA                                                                                          cal of the big space agencies;
                                                                                                                                   NASA carried SunSat into orbit,
 Orbit                     Oblique eccentric                Polar 500 km                  Polar 660 km                             piggy-back with a satellite of its
                           620–850 km                                                                                              own.

 Sensors                   4 bands in the                   6-band                        6-band                     2001          To maintain the momentum, the
                           visible and near                 Multispectral                 Multispectral                            University of Stellenbosch created a
                           infrared                         6.5 m GSD*                    Panchromatic                             company called SunSpace to design
 ∑                         15 m GSD*                        40-km swathe                  pushbroom                                and manufacture aerospace compo-
 ∑                         52-km swathe                     Panchromatic                  Panchromatic                             nents. It has supplied satellite com-
 ∑                                                          area                          area ∑                                   ponents, such as optics, sensors and
 ∑                                                                                        200-band                                 starfinders and a complete
                                                                                          hyperspectral                            microsatellite, for an international
                                                                                                                                   clients.
 Total mass                64 kg                            60 kg                         150 kg
                                                                                                                     2003          The University of Stellenbosch,
 Optics                                                     1,2 m focal                   1,72 m focal                             SunSpace, the CSIR and the
                                                            length,                       length,                                  Agricultural Research Council
                                                            200 mm                        280 mm                                   formed a consortium, the Multi-
                                                            aperture                      aperture                                 Sensor Microsatellite Imager (MSMI),
                                                                                                                                   to build a radical new imager pack-
 * GSD (Ground Sampling Distance) gives the approximate minimum size of the objects that can be seen on the ground
                                                                                                                                   age for future microsatellites*.

                                                                                                                     2006          The South African Cabinet approved
A test model of parts of
                                                                                                                                   a programme of earth observation
the MSMI telescope (the
                                                                                                                                   satellites – the ZASat series – for
black carbon-fibre tube
                                                                                                                                   launches beginning in 2006. “ZA”
on the left supports the
                                                                                                                                   is the international designation for
secondary mirror and the
                                                                                                                                   South Africa. ZASat-002 (the second
silver disk beneath repre-
                                                                                                                                   South African satellite after SunSat)
sents the primary mirror)
                                                                                                                                   is a smaller, lighter technology
and the hyperspectral
                                                                                                                                   demonstrator for ZASat-003, which
sensor optical bench
                                                                                                                                   will follow about a year later carry-
(gold-coloured box on
                                                                                                                                   ing the full MSMI package [Fig 2].
the right) on the vibration
                                                                                                                                   Both launches will take place on a
table, where it is shaken
                                                                                                                                   commercial basis from a Russian
as if undergoing a launch.
                                                                                                                                   submarine in the Arctic.
26   SCIENCESCOPE DECEMBER 2006




                                                                            A space
                                                                         agency for
                                                                        South Africa
                  – a holistic frame of reference
                                                                                             By Dr Jan Roodt




                                  T
            The South African                he key question was to deter-
                                                                              The role of a
                                           mine
      government approved                    the objectives of a space        space agency
                                             programme. Several impera-
      the establishment of a      tives were raised immediately, notably      Any systematic approach to developing a
                                  those highlighted in the Accelerated        common understanding must first acknowl-
       space agency during        and Shared Growth Initiative for South      edge those boundaries or constraints that are
                                                                              beyond manipulation. These realities dictate
       2006. Leading up to        Africa (AsgiSA) such as the develop-
                                  ment of human capital and establish-        the possible outcomes. For example, South
                                                                              Africa is a developing country with a specific
     this, a study of several     ment of empowered small businesses.
                                  The strategic value proposition for         historical context that forces certain issues to
       other agencies in the      access to space had to address these        the fore, such as ways to support the efforts
                                                                              to erase the second economy, support for
                                  issues. In doing so, it would direct the
       world highlighted the      activities of the South Africa Space        development of a scientific prowess to posi-
                                  Agency to develop this specific sector      tion the country for global recognition, and
     diverse nature of these      of the social, technology and economic      the agency’s potential to contribute to the
                                                                              realisation of the dream of the State
           organisations even     infrastructure and take into account the
                                  other initiatives, especially the aero-     President, Mr Thabo Mbeki, to see Africa
                                                                              develop into a leading force in all aspects of
            when considering      space drive.
                                         To structure and analyse this com-   life on a global stage.
              those in smaller    plex socio-technical system presented              Additional issues include the roles of
                                                                              other African countries with similar aspira-
                                  several challenges. Many of the perti-
      countries. This led the     nent factors cannot be quantified in a      tions and active space initiatives, particularly
                                                                              Algeria and Nigeria. An agency in South
                                  meaningful manner, as they link social
     Department of Science        and political dimensions and technical      Africa will clearly have, many facets ranging
                                  elements in intricate ways. Several         from technology and social dimensions to
      and Technology (DST)        uncertainties are inherently part of this   political.

         to contract the CSIR     landscape, for example, whether South
                                  Africa should develop a launch capabil-     Structuring the
     for a study to establish     ity and what the political and social       problem “space”
                                  impact of such a high-cost endeavour
        the elemental frame-      would be. Would it be economically          CSIR Defence, Peace, Safety and Security
                                  viable, or drive the development of spe-    has years of experience in dealing with large
          work of a strategic     cialised skills that would help position    system-of-system analysis and synthesis stud-
                                  South Africa for sustained growth? It       ies on behalf of the Department of Defence
      value proposition and       was obvious that a “big picture”            (DoD) and the Armaments Corporation of
        operational directive     approach was needed to develop a
                                  shared understanding of the problem,
                                                                              South Africa (Armscor). This experience and
                                                                              its strong links with the Swedish Defence
          for a South African     which would leverage the power of           Research Agency (FOI), led to the CSIR being
                                  consensus to define the shape and char-     called upon to assist with the mammoth task
               space agency.      acter of the new agency.                    of establishing a framework.
                                                                                                  SCIENCESCOPE DECEMBER 2006                    27




                                                                                                plex problem space and development of a
                                                Morphological                                   common and shared modelling frame-
                                                analysis –                                      work. This framework is open to thorough
Two stages were proposed to the DST:            discovering                                     inspection with traceability built into it.
during the first stage, a non-quantitative
analysis and synthesis would be done to
                                                the anatomy                                     Software developed by the FOI and main-
                                                                                                tained under agreement by the CSIR
develop a consensus-based launch pad for        of the SA space                                 develops and captures the model versions
the second stage that would focus on a          landscape                                       at every iteration.
technology audit and road mapping exer-                                                                Several issues or dimensions were
cise. It was hoped that this first stage        A small team of knowledgeable individu-         discussed, such as the link between the
would support the DST, who would proba-         als was proposed by the DST to partici-         current aerospace drive, near-space plat-
bly be the custodian of the agency during       pate in a workshop during June 2006 at          forms like those proposed for a novel sur-
the initial formative years, to discover        the CSIR. These people had a good grasp         veillance system called AwareNet (see
where to focus the attention of phase two.      of the dimensions relevant to the proposed      article in this issue of ScienceScope) and
This article deals only with the first stage.   effort around space in the South African        the utilisation of satellites. Attention was
      The method proposed by the CSIR           context. Participants represented the           also paid to synchronisation of these
was based on work of Dr Tom Ritchey of          Department of Trade and Industry, the           efforts for maximum effect; leveraging of
the FOI in Stockholm. His work on com-          Department of Communication, DST, the           existing capabilities in South Africa; lever-
puter-aided morphological analysis was          South African Astronomical Observatory          aging the high regard for South African
used successfully in the past by the CSIR       and the CSIR.                                   astronomy globally to enter new “clubs”
to develop similar frameworks for the                  Morphological analysis (MA) - best       of knowledge sharing to the benefit of all
DoD, such as the frame of reference for         described as facilitated creativity amongst     South Africans and eventually Africans in
the development of a cyberspace protec-         the small group of subject matter experts -     general. The latter brings to mind the
tion capability, and his method was used        uses several iterative steps or phases of       Southern African Large Telescope (SALT)
successfully on several problem spaces in       analysis and synthesis, which form the          and the work on the newest concepts of
the past . In view of his extensive experi-     basis of developing scientific models . A       radio astronomy by bidding to host or
ence, Ritchey was contracted as part of         central feature is facilitated group interac-   contribute to the Square Kilometre Array
the CSIR team to support the DST.               tion that supports structuring of the com-      (SKA) .
28   SCIENCESCOPE DECEMBER 2006




                                        The diagram shows a specific con-                 The traceable model can be used to
                                  figuration of the final MA map as it was         discover or understand relationships and
                                  delivered to the DST.                            is the result of consensus amongst the
                                  Six dimensions are shown: each of these          workshop participants. However, several
                                  “variables” is populated with a number of        presentations to stakeholders confirmed
                                  “states”. For example, the dimension or          that experts covered the important ele-
                                  variable “Current Programs” has the              ments adequately. This model may be
                                  states:                                          expanded in future to accommodate new
                                  1) SKA                                           insights (with traceability inherent) and the
                                  2) Micro satellites                              current thinking, based on current informa-
                                  3) ARMC                                          tion, is captured for further synthesis and
                                  4) SAEON                                         analysis.
                                  5) COMSAT
                                  6) SECURITY
                                                                                   What was
                                  These states are linked to current endeav-       discovered?
                                  ours in South Africa.
                                                                                   This model has a specific context and can
                                         The model may be used to inspect          be used only to analyse the environment it
                                  links and synergies. In the case shown           was designed for, in this case space-relat-
                                  (MICRO SATELLITES being selected as the          ed programmes, facilities, stakeholders,
                                  state in the variable CURRENT PRO-               etc. When interrogating the model, sever-
                                  GRAMS), it is clear that all national imper-     al interesting observations were made.
                                  atives are answered by developing an             It is obvious that a South African Space
                                  industry in micro satellites and that space      Agency (SASA) must answer to national
                                  research, frameworks for industrialisation,      imperatives. Through well-designed pro-
                                  earth observation and satellite engineer-        grammes, it will have to advance the level
                                  ing will benefit from such a project. At the     of science and technology, human
                                  same time, it can be seen that certain           resources development, go beyond sci-
                                  facilities must exist, like the CSIR Satellite   ence and technology and deliver growth
                                  Applications Centre, which are govern-           in such diverse fields as logistics and
                                  ment-owned or controlled facilities. No          legal affairs. It must impact the quality of
                                  industries were considered, as it is left        the lives of the population on several lev-
                                  open to government to decide how to              els, including cultural pride and heritage
                                  empower industry, given these insights.          and open the door to the exclusive clubs
                                                                                             SCIENCESCOPE DECEMBER 2006   29




of nations with access to space to allow      deeper positioning around cultural knowl-
South Africa and Africa to share in the       edge is shown, funding becomes a sec-
rich diversity of knowledge available to      ondary issue.
these nations. At the same time, it should           South Africa will play a major role
open up opportunities for South African       in the establishment of the SKA, whether it
industries to carve niches for themselves.    is built in Africa or Australia. This means
South Africa has a wonderful heritage in      that our signal processing knowledge and
astronomy. It is now obvious that the SKA     system engineering ability will grow,
will be situated either in South Africa or    which will definitely impact our growth
Australia. In any event, the current work     potential positively as we seek to develop
on prototypes for the SKA will enable         large projects in Africa, including devel-
South Africans to contribute to a global      opment of infrastructure and communica-
pool of knowledge through our system-         tion links supported by our space efforts.
level engineering and signal processing       Collaboration with large suppliers of com-
abilities, as is evident from the technolo-   munication and geo-positioning satellites
gies that underpin the programmes and         becomes a possibility: we could now link
functions shown in the map.                   into the Galileo global positioning system,
                                              for example, and work with companies
The next steps                                like Alcatel Alenia Space in France, one
                                              of the largest suppliers of large satellites
The strengths of the South African technol-   in the world, while simultaneously carving
ogy base can easily be deduced from this      a niche in hyper-spectral optical sub-sys-
morphological analysis. This must be used     tems for these satellites.
during the next phases to develop technol-           The opportunities are endless and
ogy and developmental roadmaps and            the South African spirit of innovation is
during audits of existing capabilities. It    acknowledged widely. It will be the task
will allow for risk mitigation and the        of the SASA to develop the landscape
focused application of scarce resources.      through appropriate action within the
Small economies cannot defend large           established holistic framework.
research programmes that do not deliver
medium-term social impact. As was
argued recently by Mostert and Roodt , a      Enquiries:
science such as astronomy is a good           Dr Jan Roodt
example where social benefit is slow to       Tel +27-12-841-4847
materialise, but once the benefits of a       Email jroodt@csir.co.za
30    SCIENCESCOPE DECEMBER 2006




                                                                     CSIR gas turbine
                                                                technology smartens
                                                                    up future aircraft
                                                                                          By Philip Haupt and Glen Snedden




     T
              echnology projects ranging from        equipment manufacturers on three conti-         operational environment.
              the design of entire engines to the    nents (Rolls Royce in the USA, Snecma in                Hot-and-high takeoff conditions
              detailed analysis and repair of        France and Klimov in Russia) on some of         prevalent on the South African Highveld
              specific components have been          the most important defence projects in          result in two damage mechanisms. Firstly,
     developed at the CSIR in the field of gas       South Africa’s industrial history.              the overall temperatures in the main gas
     turbine technology over the past 25 years.             Currently the CSIR is developing         path in the aircraft engines are elevated
     Current research and development (R&D)          tools, expertise and techniques to be able      by a function of the increased inlet tem-
     is driven by international relationships and    to support the SAAF in the use and acqui-       perature, an effect which can lead to
     alliances, whereas most requirements, and       sition of new strategic assets, as well as in   severe component damage, especially to
     hence expertise, were initially driven by       maintaining its aging fleet. This is            those in the hottest part of the engine. The
     the needs of the South African Air Force        achieved via two technology defence proj-       second, and by far the more significant
     (SAAF).                                         ects involving nine institutes and universi-    mechanism since it cannot be eliminated
           The CSIR harnesses skills from across     ties, and technology partnerships with          by reducing thrust as is the case for the
     the country through an inclusive network        original equipment manufactures such as         first mechanism, is the increased tempera-
     of universities and institutes to develop       Volvo Aero in Sweden and Snecma                 ture and reduced volumetric flow of the
     and retain key gas turbine R&D technolo-        Moteurs in France.                              coolant air to those same hot components.
     gies, particularly for the hot-end - or tur-                                                    These include the nozzle guide vane, the
     bine section - of a gas turbine engine.         Current activities                              first stage rotor blade and their supporting
     Hot-end technology is seen as a main                                                            discs.
     enabler in the development and mainte-          Over the past three years the CSIR has                  The CSIR focuses on understanding
     nance of gas turbines world-wide and is         moved towards the smart user/smart              these aerothermodynamics, heat transfer
     heavily controlled by the world’s leading       buyer philosophy. Nevertheless, the major       and stress damage mechanisms and pro-
     nations such as the USA. It is therefore tes-   technological focus is still to minimise the    viding a better understanding of potential
     timony to the CSIR’s skills and experience      effects of the hot-and-high environment in      maintenance problems, as well as provid-
     that the group has worked with original         South Africa, as well as the associated         ing capabilities to reverse-engineer and
                                                                                                   SCIENCESCOPE DECEMBER 2006                     31
re-design the components to reduce these       While the equipment and levels of technol-           fatigue testing of titanium and superalloy-
damaging effects.                              ogy may change, the basic operational                based components for commercial air-
       One of the most successful projects     environment has not. The same situation              craft engines and is currently developing
of this nature has been the CSIR’s close       can be envisaged for the future, along               an internationally accepted quality sys-
involvement with 28 Squadron of the            with some new difficulties resulting from            tem adhering to ISO17025.
SAAF and their fleet of C130 Hercules          the increased level of technology inherent      •    The CSIR has been included in the EU
transport aircraft. The C130 engine manu-      in the newer engines being purchased by              FP6 project VITAL (EnVIronmenTALly
facturer, Rolls Royce Corporation, reduced     the South African government. The main               Friendly Aero Engine), which aims to
the cycle life of particular hot-end compo-    challenge is to push the available minds             reduce the noise, fule use and polluting
nents by over 60% and removed the flight       and tools forward two decades as illustrat-
                                                                                                    emissions from aircraft. As part of proj-
hour limit, which necessitated the SAAF to     ed in Table 1.
                                                                                                    ect VITAL, some CSIR engineers will work
verify the claims of the manufacturer inde-
                                                                                                    on PhD studies at Durham University in
pendently. This led to the CSIR undertak-      To cope with the leap in technology repre-
                                                                                                    the United Kingdom, undertake the refur-
ing a detailed reverse engineering,            sented by the new engines currently enter-
aerothermodynamic and structural analy-                                                             bishment of the CSIR turbine test rig, and
                                               ing local service, the CSIR is utilising the
sis programme of the engine components         traditional Department of Defence (DoD)              develop appropriate international net-
involved. Once the models and analysis         sources of funding, as well as funds from            works. This is aimed at ultimately devel-
tools were put in place, Rolls Royce           the Departments of Science and                       oping CSIR-based unique testing capabil-
Corporation was satisfied with the CSIR’s      Technology (DST) and of Trade and                    ities to validate low-pressure turbines
analysis capabilities and the CSIR became      Industry (the dti) and the European Union            destined for the next generation of airlin-
full partners in the programme to investi-     (EU) to consolidate existing knowledge               er engines.
gate and solve this problem. Other part-       and facilities. The network with local and      •    The CSIR has maintained its six-year mem-
ners were the National Research Council        international universities and original              bership on the Society of Automotive
(NRC) in Canada, the United States Navy,       equipment manufacturers is also being                Engineers Aerospace Committee on
the United States Air Force and the            expanded, and skilled individuals are                Engine Condition Monitoring that creates
Defence Science and Technology                 increasingly being developed through                 international engine safety and analysis
Organisation (DSTO) in Australia.              links with specific international gas turbine        standards for both commercial and mili-
       The CSIR performed computational        companies such as Volvo Aero and                     tary gas turbines.
fluid dynamics and transient stress analy-     Snecma Moteurs.                                 •    South Africa and the CSIR have main-
ses, both advanced 2D and detailed 3D                                                               tained national membership of the
models, as input to the final component        Recent highlights include:                           International Symposium on Air
life assessment. The organisation also con-    • The CSIR’s aerospace investment                    Breathing Engines since the early 1980s,
structed the high-fidelity mission cycle for      foundry has undergone a facility                  which is the only international forum on
all the users, performed the stress analysis      upgrade and is involved in collabora-             gas turbines. South African participation
of spin pit components and the develop-           tive research with Volvo Aero in the              has grown from no papers in the late
ment of the only CAD model of the T56 in          casting of thin-walled superalloy struc-
existence today. In addition, the CSIR per-                                                         1990s to four papers in 2007.
                                                  tures, such as engine support vanes.
formed independent life assessment analy-      • A CSIR engineer, Euodia Kruger, has
ses to verify the calculations reported by                                                     Enquiries:
                                                  been seconded to Volvo Aero to work
Rolls Royce Corporation.                                                                       Philip Haupt
                                                  on the aerodynamic design of                 Tel 012-841-2447
       While the final result may not be
                                                  advanced turbine concepts for EU             Email phaupt@csir.co.za
encouraging (the reduced life was unfortu-
                                                  Framework projects.
nately confirmed), the value of the models
                                               • The CSIR’s mechanical testing labora-         Glen Snedden
and data transferred are immeasurable to
the safe and cost-effective operation of the      tory has been upgraded in partnership        Tel 012-841-3094
aircraft in future.                               with Snecma Moteurs to undertake             Email gsnedden@csir.co.za

Collaboration                                    Table 1: Technology migration in gas turbines

The CSIR turbine technology area                  Atar 09K50                                   Volvo RM12
collaborates with the following entities:
                                                  •   1960s design based on a                  •    1980s design
• University of Pretoria
                                                      1940s design                             •    Advanced low bypass ratio twin
• Stellenbosch University                         •   Simple turbojet, single spool                 spool cycle
• University of KwaZulu-Natal                         cycle                                    •    Single crystal castings
• University of the North                         •   Welded fabrications                      •    27:1 pressure ratio
• University of Northwest                         •   6,15:1 pressure ratio                    •    Transonic compressor blading
• University of Cape Town                         •   NACA65 type compressor,                       with controllable guide vanes
                                                      subsonic blading                         •    FADEC controls
• Premier ThermoFluids
                                                  •   Hydraulic controls                       •    Massively film cooled NGVs and
• SAAF                                            •   Impingement cooled NGV,                       rotors with internal serpentine
                                                      uncooled rotors. Afterburner                  passages
Future role                                           ring flame stabilisers                   •    Cooled cooling air
                                                  •   Converging nozzle                        •    Reduced length combustor cans
The CSIR gas turbine technology area is                                                             and afterburner with radial
                                                                                                    flame holders
putting technology in place to support
                                                                                               •    Converging/diverging nozzle
new and future aircraft acquisitions.
32    SCIENCESCOPE DECEMBER 2006



     CSIR activities in light
                                                                                                     •∑Wind lidars can remotely measure
                                                                                                       wind speed versus distance.
                                                                                                       Applications range from global wind

     detection and ranging                                                                             field measurements from atmospheric
                                                                                                       and weather research to air-traffic safe-
                                                                                                       ty;
                                                                                                     •∑Backscatter lidars measure the dis-
     By Dr Jan van Aardt, Anton du Plessis, Christoph Bollig and Corné Eloff                           tribution of atmospheric particles called
                                                                                                       “aerosols” versus distance. They are
                                                    Taking the speed of light into account, it is      used to monitor the concentrations of
     Introduction                                   possible to determine the distance to the          dust, smoke, haze and thin clouds in
                                                    measurement point by measuring the time            the atmosphere.
     Although light detection and ranging
                                                    it takes for the light to return to the lidar.
     (lidar) has been used for monitoring the
                                                    The most important types of lidars are:          While most lidars are ground-based sys-
     world’s natural resources since the mid-to-
                                                                                                     tems, it is worthwhile noting that all of
     late 1980s, it is still regarded as a rela-
                                                    •∑Range finders determine the dis-               these are also operated on aircraft plat-
     tively recent remote sensing technology.
                                                      tance to a target and are widely used          forms by National Aeronautics and Space
     Lidar, which is based on laser technology,
                                                      in industrial and military applications.       Administration (NASA) and European
     can rightly be considered the optical ana-
                                                      Mounted on an aircraft, they can be            aerospace agencies such as ESA. Range-
     logue of the better-known ranging tech-
                                                      used to determine ground and vegeta-           finding and backscatter lidars are already
     nique of radio detection and ranging
                                                      tion profiles;                                 incorporated on satellites. Lidar data have
     (radar). A lidar measures a certain quanti-
                                                    •∑Gas and pollution detection                    obvious potential benefits South African
     ty at a distance to the lidar system.
                                                      lidars: The so-called “Differential            scientific and public institutions. Both
            Its technology is based on simple
                                                      Absorption Lidar” (DIAL) can detect gas        NASA and ESA are investigating the pos-
     principles, but requires advanced technol-
                                                      concentration versus distance. It relies       sibility of launching a wind lidar into
     ogy to implement. Different types of lidar
                                                      on the characteristic light absorption         space for global wind measurements.
     exist; all of them dependent on a laser to
                                                      features of gases. Typical applications
     emit laser pulses and for the detection sys-
                                                      are water vapour measurements and
     tem too. The laser pulses are sent out into
                                                      air pollution monitoring;
     the atmosphere and the light is scattered
     back either from atmospheric particles or
     from a “hard target”.




                                     (a) Surfaces interpolated from small-
                                    footprint lidar data that represent the
                                    top-of-canopy and ground digital ter-
                                     rain models, and (b) differencing the
                                   two surfaces in (a) results in a canopy
                                 height model, where brighter tones rep-
                                          resent taller tree and vice versa
                                                                                                   SCIENCESCOPE DECEMBER 2006                     33
      At the CSIR, lidar research is carried    old-age growth, understory vegetation and         tral-structural data sources, as well as
out in various research areas: natural          young pioneer species. Not only can for-          characterising the nature of vegetation for
resource assessment applications; built         est structure be characterised in this man-       non-utilisation purposes, e.g. threats to
environment characterisation; and lidar         ner, but by interpolating the first return hits   power lines where tall exotic species can
sensor development.                             and the last, known as the ground-return          be removed, but indigenous species have
                                                hits, it is also possible to derive top-of-       to be managed.
Lidars in forestry                              canopy and ground digital terrain models
                                                (DTMs).                                           The CSIR is involved in ground-based lidar
Forest applications can serve as useful                The result of logically-subtracting the    development for application to the detec-
examples for describing the various types       ground DTM from the canopy DTM, is the            tion of atmospheric gases. This method of
of range-finding lidars. An airborne profil-    canopy height model (CHM; Figure 1)               remotely determining gas densities at high
ing lidar literally acquires range informa-     which in turn can be used for forest inven-       accuracy is one of the most widely used
tion in a transect (linear) sampling            tory purposes to derive individual and            applications of lidar world-wide, especial-
scheme, thereby providing the researcher        average tree heights. It is important to          ly in pollution monitoring. An interesting
with a profiled “slice” of the target area.     note that the magnitude of lidar hits for         new application of this technology is a
One can typically think of a graph that         relatively small areas is restrictive in terms    current project involving the detection of
depicts height on the y-axis and distance       of processing requirements, which makes           isoprene emission from living plant materi-
on the x-axis. One is thus provided with a      the technology not quite applicable for           al, in particular Eucalyptus plants.
side-view of a forest that very effectively     purposes other than digital elevation             Isoprene is termed a biogenic volatile
highlights the range of heights along that      model (DEM) derivation, flood mapping,            organic compound and is of interest in
transect, e.g. tall trees, pioneer species      building measurement, power line assess-          atmospheric chemistry studies, since it
and so-called “ground hits”. But what           ment, etc. Large-footprint lidar however          plays an important role in the formation of
about the surrounding vegetation struc-         offers a potential solution for sampling          ozone and NOx. These molecules (ozone
ture?                                           larger areas.                                     and NOx) can also potentially be target-
       Small-footprint lidar sensors emit              Large footprint or waveform sensors        ed with lidar technology; this is currently
pulses at very high frequency, typically in     typically have footprint diameters in             being pursued as a potential research
excess of 30 kHz. Each of these pulses          excess of 20 m. The energy signal is inte-        topic at the CSIR National Laser Centre.
travels to the target and based on beam         grated across the entire footprint, which
divergence at the sensor, will typically        results in a height value on the y-axis and       The CSIR Satellite Applications Centre
yield a footprint of <1 m diameter. These       an associated energy response on the x-           views airborne lidar technology as a com-
pulses are emitted in a zig-zag scanning        axis. This is a very useful technique for         plimentary technology to precision correct
pattern as the plane travels across the         estimation of forest biomass, which in turn       remote sensing products. Application
landscape and the sensor sweeps across          is critical to applications like carbon sink      requirements from the broader user com-
the direction of travel. Airborne, small-       and source determination. One can literal-        munity highlighted the need for 3D terrain
footprint lidar data typically have point       ly correlate the energy response at each          models of metropolitan areas with very
densities of >2 hits per square meter,          height to the biomass that intercepted and        high resolution imagery as a backdrop.
since the plane can acquire various over-       returned that signal. Footprints are not          Planning for World Cup 2010, for
lapping flight lines by travelling up and       contiguous, but rather exhibit a pre-deter-       instance, could benefit from lidar technolo-
down the area of interest.                      mined spacing in a systematic sampling            gy through 3D reconstruction of stadiums
       As a sign of sophistication, many        fashion, very similar to how a giant would        with computer-aided design (CAD) soft-
sensors have what is called “multiple           tread across the landscape. Potential             ware utilising lidar ground and non-
return capabilities”, meaning that a single     applications include derivation of global,        ground points. The potential also exist for
pulse can be recorded more than once,           course-resolution DEMs, global vegetation         military and safety and security institutions
depending on the amount of energy that          biomass assessment, and large-area disas-         to improve their spatial intelligence using
is returned to the sensor at various travel     ter management.                                   this technology.
times. In the forest example; a single pulse
can hit the top of the tree canopy, return a    CSIR involvement in                               The future
portion of the energy to the sensor, and
some of that same pulse energy can hit
                                                lidar applications                                This exciting technology offers many novel
understory vegetation, in turn returning a                                                        opportunities that the CSIR is exploring as
portion of the energy of the same pulse to                                                        lidar applications research spans many
                                                CSIR Natural Resources and the
the sensor. Many sensors have up to five                                                          activities within the CSIR scope. South
                                                Environment is involved in forestry appli-
returns for each pulse, which allows                                                              Africa is already on its way to becoming
                                                cations, which include structural assess-
researchers to characterise vegetation                                                            one of the few nations that can boast a
                                                ment (inventory) of forest resources and
structure. An even-aged, homogeneous                                                              hyperspectral satellite in space, why not
                                                investigating the spectral-structural interac-
pine plantation might have a first return                                                         strive for a spaceborne lidar sensor?
                                                tion of vegetation. The latter aspect is of
(top-of-canopy), followed by a second
                                                particular importance since it guides the
return (bulk of canopy biomass), and a
                                                interpretation of remotely-sensed imagery
final (third) return from the ground,
                                                that is influenced by a variety of factors,       Enquiries:
depending on whether there is enough                                                              Corné Eloff
                                                among which structural variability -
open space for the signal to penetrate. A                                                         CSIR Satellite Applications Centre
                                                objects might “look” the same, but not
more complex uneven-aged heterogeneous                                                            Tel 012-334-5058
                                                “feel” the same, and vice versa! Other
indigenous forest may have up to five                                                             Email celoff@csir.co.za
                                                projects include characterisation of exotic
returns, mainly due to the fact that the for-
                                                and indigenous vegetation through spec-
est structure is typically more complex with
34    SCIENCESCOPE DECEMBER 2006




     Water is essential to
     all aspects of life, yet 99% of the water on
     earth is unsafe or unavailable to drink. Some 1,2 billion
     people globally lack safe water to consume and 2,5 billion do not have access
     to adequate sanitation. Its estimated that 9 500 children die world-wide every day
     from water-related diseases and a lack of clean drinking water. Water is an economic
     issue as it is essential for poverty reduction, agriculture, food and energy production.
                                                    Water of the UK. The project was inspired   ply of quality water to users, while ensur-
       CSIR helps raise                             by former US Senator Paul Simon's power-    ing the integrity of the resource so that

            awareness                               ful book, "Tapped Out".
                                                          Speaking at a media briefing before
                                                                                                economic growth and prosperity is
                                                                                                realised despite environmental constraints.
          about global                              the event, CSIR water expert Bettina
                                                    Genthe said the CSIR was acutely aware
                                                                                                This research is conducted in the areas of
                                                                                                groundwater, water ecosystems, health
         humanitarian                               of the urgency of addressing water issues
                                                    in southern Africa. Research efforts are
                                                                                                and governance and is in line with the
                                                                                                CSIR's commitment to improving quality of
           water crisis                             focused on assessing and managing           life and growing the economy, both
                                                    water resources to ensure an optimal sup-   nationally and regionally.
     A documentary, intended as a global call
     to action regarding the evolving world
     water humanitarian crisis, made its debut
     in South Africa when it was screened at
     the CSIR in November.
           Running Dry, written, produced and
     directed by Jim Thebaut and narrated by
     Jane Seymour, sets out to raise awareness
     regarding the worsening global humani-
     tarian water crisis, a message that is par-
     ticularly relevant in South Africa. The film
     focuses on life-and-death crises with water
     and sanitation in China, India, South
     Asia, South Africa and the Middle East.
     Mrs Lindiwe Hendricks, Minister of Water
     Affairs and Forestry, hosted the event and
     delivered the keynote address. The event
     was organised by the CSIR and Thames
                                                                                             SCIENCESCOPE DECEMBER 2006                   35


                                                                       Sea conditions and
                                                                       cholera outbreaks
                                                                       researched in
Safe drinking water                                                    Mozambique
from the sun                                                           CSIR environmental researchers are
A simple, low-cost technique to provide safe drinking water, and       investigating the potential role that
thereby avoid water-borne diseases such as cholera, dysentery
and polio, is the subject of a new European Union-funded project.      various sea conditions play in cholera
The CSIR is one of three African participants in the project.          outbreaks. The researchers are focus-
       The SODISWATER project aims to demonstrate that water
can be disinfected using only a water bottle and a steady supply       ing their efforts on an area in Beira,
of sunlight. This technique can help vulnerable communities in
developing countries that do not have a reliable, safe water sup-
                                                                       a coastal city in Mozambique.
ply and who might find themselves exposed to natural or man-
made disasters.                                                        Cholera is an acute bacterial infection of the small intestine,
       According to the World Health Organisation (WHO), over 1        caused by Vibrio cholerae and characterised by massive diar-
billion people around the world have no access to any kind of          rhea with rapid and severe depletion of body fluids and salts.
treated drinking water. Every year 1.6 million people, most of         The bacteria enter the body via the mouth, usually in contami-
them young children, die of diarrhoeal diseases such as cholera        nated water or foods, and cause an infection in the mucous
that are attributable to a lack of access to safe drinking water and   membranes lining the lumen of the small intestine.
basic sanitation. Millions more are infected with water-borne par-            The project focuses on environmental conditions of the
asites.                                                                disease and not on the social conditions promoting outbreaks.
       Solar disinfection has been approved by the WHO and is          The multi-disciplinary team is investigating the ecology of the
commended for its proven efficiency in the aftermath of the            bacteria to determine whether there are linkages between
Tsunami disaster in southeast Asia in 2004.                            cholera outbreaks in the area and various land and sea condi-
       Martella du Preez, a senior researcher at the CSIR, says the    tions. They are developing a model based on the data related
technique is simple: solids are removed by settling or filtration.     to certain environmental factors and the number of cholera
The water is placed in a clear bottle and shaken vigorously to         cases.
aerate the water. Under the heat of the sun, the water soon reach-            While research continues, preliminary findings indicate
es temperatures in excess of 50-60°C. Combined with ultraviolet        that the area is an environmental reservoir for the bacteria.
radiation from the sun, this will inactivate many viruses, bacteria    The research team has found patterns and consistencies in the
and parasites within a few hours.                                      data relating to environmental factors and cholera outbreaks.
       Over the next three years, the multidisciplinary research       The cholera bacteria have also been identified in samples
group will investigate the factors that influence communities to       taken along the coast line of Beira and in the estuary close to
adopt or reject SODIS; whether the basic technique can be              the city. The team is investigating the entire landscape and is
improved using simple technologies and whether there are any           analysing remotely-sensed as well as in situ data on parame-
major waterborne diseases that can't be prevented through              ters, such as air and sea surface temperature, chlorophyll in
SODIS. The team comprises the Kenyan International Community           the sea and rainfall.
for the Relief of Suffering and Starvation, the Institute of Water            Cholera bacteria survive in the sea and can contaminate
and Sanitation Development in Zimbabwe, the Royal College of           marine resources such as shellfish. Using remote sensing data,
Surgeons in Ireland (RCSI), the University of Ulster, the University   the researchers are investigating the overall pattern of the
of Leicester (both in the United Kingdom), the Swiss Federal           occurrence of chlorophyll and its potential link with cholera.
Institute of Aquatic Science and Technology, the University of         Researchers in other parts of the world have shown the bacte-
Santiago de Compostela and the Plataforma Solar de Almeria,            ria to be associated with the zooplankton. The cholera bacte-
both in Spain.                                                         ria are carried by copepods - a zooplankton - and where there
                                                                       is chlorophyll, zooplankton are found.
As part of the agreement, CSIR researcher Eunice Ubomba-Jaswa                 ”The CSIR research team, comprising earth observation
has travelled to Ireland to take up a three year PhD research posi-    experts, mathematical and statistical modellers, microbiologists
tion under the supervision of Dr Kevin McGuigen, Department of         and oceanographers, will continue their work to generate evi-
Physiology and Medical Physics at the Royal College of Surgeons        dence to prove, or disprove, the potential sea-based link,”
in Ireland. She will spend 18 months in Ireland and England and        says research leader Marna van der Merwe.
then move to Spain to complete her experiments.
                                                                       Enquiries:
Enquiries: Martella du Preez                                           Marna van der Merwe
Tel 012-841-3950                                                       Tel 012-841-3397
Email mdupreez@csir.co.za                                              Email mvdmerwe@csir.co.za
36     SCIENCESCOPE DECEMBER 2006




                                                           The BCLME programme acknowl-
                                                     edges that nature does not heed man-            Biodiesel waste
                                                     made boundaries - environmental prob-
                                                     lems occur across national boundaries. As       to be used
                                                     part of this programme, marine scientists
                                                     and experts from Angola, South Africa           in animal feed
                                                     and Namibia have pooled their resources
       Dredger tailings discharged to the
                                                     for the past four years, working on numer-
       intertidal zone on the Namibian
                                                     ous projects to protect the ecosystem of
                                                                                                     South Africa's
       coast. Image courtesy: Namdeb
       Diamond Corporation.                          one of the most productive ocean areas in       Department of Science
                                                     the world, the Benguela current region.
                                                           CSIR sediment dynamics specialist         and Technology (DST)
                       Action                        and leader of the project on sediment dis-
                                                     charges from diamond mining, Geoff
                                                                                                     has awarded funding
                      needed                         Smith, says in recent years some diamond
                                                     mining operations have resulted in the dis-
                                                                                                     to the CSIR for research
                                                                                                     on the beneficiation of
        to reduce impact                             charge of up to several million tons of tail-
                                                     ings at a single site annually.                 biodiesel by-products
     of diamond mining                                     “Several future mining operations
                                                     are planned to be of a similar scale. This      and its possible
     in Benguela region                              study was rooted in a concern that cumu-
                                                     lative effects, over time and space, may
                                                                                                     economic spin-offs
                                                     be severe,” Smith explains. The project         for rural agricultural

     S
             outh Africa, Namibia and Angola         area covered a section of the Namibian
             need to consider additional environ-    coastline from the Olifants River (in the       communities.
             mental management and monitoring        south), to Spencer Bay (in the north), and
     actions to better understand and mitigate       from the high-water mark extending to 40        The main objective of the research is to
     the effects of discharged sediments result-     m in depth.                                     improve the nutritional value of oil cake,
     ing from near-shore and coastal diamond                                                         a biodiesel by-product, thereby increasing
     mining. This advice is contained in a           Other findings included:                        its inclusion levels in animal feed, specifi-
     report, compiled under the leadership of        • Natural sediment (from the Orange             cally pig and poultry diets and fish food.
     the CSIR, on the cumulative effect of dis-        River) and windblown sediment tend to         Animal feed trials and related research
     charges resulting from such mining activi-        be fine. Most of the sediment dis-            will be done in collaboration with the
     ties in a defined area in the Benguela            charged from mining, however, is              Agricultural Research Council (ARC).
     Current Large Marine Ecosystem (BCLME)            medium to coarse sand. The fine sedi-         Research will also be conducted into its
     region.                                           ment is mobilised by wave action and          possible future use beyond animal feed.
            It is estimated that 400-800 million       is transported rapidly, generally north-      Another objective is to increase the eco-
     tons of sediment from the Orange River            ward, by wind and wave-driven cur-            nomic viability of biodiesel and create
     was discharged from 1968 to 2005 in               rents. This is not the case with coarse       manufacturing industries in semi-urban
     this area. In comparison, it is estimated         mine sediment, which generally results        and rural areas.
     that about 400 million tons of sediment           in accretion.                                         “Research on value addition to the
     resulted from near-shore and coastal dia-       •∑The discharge of large volumes of sand        soybean oilcake will require investigations
     mond mining during the same period.               can result in long-term (years to             into other areas, such as the de-hulling
            The research project was one of 75         decades) deposition on reefs, which           process, the type of oil production,
     linked to the BCLME, which received fund-         overshadows natural trends. By 2013,          variability in raw materials and selection
     ing to the tune of R65 million through the        an estimated total of about 3 km of           and type of oilseed,” explains Dr Gatsha
     United Nations Development Programme              rocky inter-tidal and near-shore sub-         Mazithulela, Executive Director of CSIR
     (UNDP) over the past four years. The              tidal smothering of reef in the demon-        Biosiences. During the research project,
     BCLME programme aims to pave the way              stration areas will occur.                    soybeans and sunflower seeds will be the
     for the three countries of the Benguela -                                                       two main crops used for biodiesel produc-
     Angola, Namibia and South Africa - to           Recommendations put forward include that        tion. Information on these two readily-
     manage the region’s valuable marine and         detailed logs should be kept of the hourly      available crops is extensive and the use
     coastal resources and to strike a better        and daily rates of all sediment discharges,     of the oilcake by-products is established
     balance between human needs and con-            as well as accurate directional wave            in the animal-feed market. “The project
     servation issues.                               measurements and wind data in mining            will draw on the expertise of food scien-
            The Benguela current region is situat-   areas.                                          tists, fermentations specialists, process
     ed along the coast of southwestern Africa,                                                      chemists and biotechnologists of the
     stretching from east of the Cape of Good        Enquiries:                                      CSIR,” comments Mazithulela.
     Hope in the south, northwards to Cabinda        Geoff Smith
     in Angola and encompassing the full             Tel 021-888-2564 Email
     extent of Namibia’s marine environment.         gsmith@csir.co.za
                                          A
                                                         research consortium led by
                                                         the CSIR has received a sub-
                                                         stantial international grant to
                                                         explore an advanced method
                                                         of nutritionally enhancing two
                                          of Africa’s major staple food crops without
                                          introducing any foreign genes to these
                                          plants. The Agricultural Research Council
                                          and the University of Pretoria are the
                                          CSIR's research partners in this project.
                                          The revolutionary method of altering the
                                          plant’s own genetic signals without intro-
                                          ducing any foreign genes is based on
                                          nuclear radiation technology. The grant
                                          was awarded by the International Atomic
                                          Energy Agency (IAEA), a specialised
                                          agency of the United Nations.
                                                 Commenting on the grant, CSIR
                                          Biosciences Executive Director, Dr Gatsha
                                          Mazithulela, says: “The CSIR’s commit-
                                          ment to provide biosciences solutions for
                                          improving health and fighting diseases is
                                          aligned with the IAEA’s role in contribut-
                                          ing to the Millennium Development Goals
                                          for social, economic and environmental
                                          development.” The IAEA promotes safe
                                          and peaceful uses of nuclear science and
                                          technology.
                                                 “In Africa, trends in child malnutri-
                                          tion, household food insecurity and pover-
                                          ty are moving in the wrong direction.
                                          Some crops grown in the region are also
                                          low in major nutrients and vitamins. The
                                          CSIR’s aim is to improve the lives of peo-
                                          ple; our biosciences researchers are
                                          directing their scientific endeavours at
                                          improving the nutritional value of African
                                          staple crops. We believe all technologies
                                          should be explored as a means to achieve
                                          this, including conventional breeding,
                                          genetic engineering and nuclear science

                       CSIR to improve
Biotechnologist                           coupled with large-scale screening,” says
Nosisa Dube is par t                      Mazithulela.
of a CSIR team who                               The two-year grant, which is likely
will use the IAEA
grant to research          cereal crops   to be extended for another two years,
                                          will allow biotechnologists to conduct
modification of

                         without using
                                          research on the modification of maize and
maize and sorghum                         sorghum by exposing plant material to
using nuclear radia-                      radiation. Gamma rays cause random

                         foreign genes
tion technology and                       modification in endogenous biochemical
not genetically mod-                      pathways. The randomness of these
ified organisms                           changes results in broad genetic varia-
                                          bility, which scientists could use to
                                          leverage other studies such as developing
                                          plants that are heat tolerant, drought
                                          tolerant and cold stress tolerant.
THE CSIR’S OPERATIN G UNITS, NATIONAL RESEARC H CENTRES AND SERVICES

I CSIR Biosciences
          Pretoria (012) 841-3260
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          Pretoria (012) 841-2034

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          Pretoria (012) 841-2780

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          Pretoria (012) 841-2411
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          Pretoria (012) 841-2674
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          Durban (031) 242-2300
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I Meraka Institute
          Pretoria (012) 841-3028

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          Pretoria (012) 841-4188

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          Pretoria (012) 841-4152

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          Hartebeesthoek (012) 334-5000

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          Pretoria (012) 841-2525




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Photography: Gerry le Rouw, Loretta Steyn, Rudi van Aarde, ?????




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