Satellite Motors

Les Mureaux, 07/09/2001 Note PADC 129/01 A 0 Page 1 / 7 Direction Commerciale et marketing ESTEC Contract No 14818/00/NL/PA Assessment Study on the Application of Solid Propulsion to Satellites EXECUTIVE SUMMARY DRAFT DOCUMENT Evolution Indexes Index Edition Revision Modified paragraph Evolution references & sum-up Date A 0 - Original issue 07/09/01 Distribution ESA / ESTEC M. LANG I. KÄLSCH F. FELICI Name Company Date Visa Approved by B. Lallemant PyroAlliance This document is the property of PyroAlliance - Propulsion Division - SNPE Group. Its contents shall not be disclosed. ? PyroAlliance - Propulsion Division - SNPE Group - 2001. Les Mureaux, 07/09/2001 Note PADC 129/01 A 0 Page 2 / 7 Direction Commerciale et Marketing 1) Introduction This document constitutes the executive summary of the " Assessment study on the application of solid propulsion to satellites". The related works have been led in cooperation with Bertin Technologies of Montignyle-Bretonneux (F) and are co-funded at a 50/50 ratio by ESTEC, under the contact N° 14.818/00/NL/PA [1], and by PyroAlliance – Group SNPE / Propulsion Division (F). As a general specification [3], this assessment study aims at finding solid propulsion applications so as to state their performance characteristics and to give design and illustration of the suitable solid propulsion subsystems that could be used for to-day and future satellite missions, either to fulfil entire functions, such as the satellite de-orbiting [2], or to optimize the propulsion system by working alongside with other technologies such as electrical propulsion equipment. The assessment study, treating of solid propulsion to satellites, is divided in three main parts : a) System study : Satellite mission analysis (Work Package 1200) [4] : After the definition of the satellite missions, while bringing into account the satellite characteristics, the influence of the launch possibilities and the induced requirements, notably as concerning the orbit insertion and the space environment, it is provided an overview of the potential propulsion needs for every satellite mission. Finally, by the illustration of the thrust versus the burn time for the unit impulses, performed for achieving the satellite propulsion functions, the potential application areas for solid propulsion can be assessed. b) Propulsion subsystem study : Architecture definition (WP 2100) [5] : After having considered the advantages and drawbacks of the existing propulsion technologies, the various propulsion system architectures, for which the solid propulsion is bringing advantages and may be used as an add-on system, are developed in terms of required characteristics for dealing with the corresponding satellite propulsion functions. Thus, five applications of the solid propulsion to satellites are pointed out. : Trade-off & Architecture optimization (WPs 2200 & 2300) [6] : Relatively to the specific types of satellite missions, for the five identified applications where solid propulsion may be advantageous, a trade-off is led between all the candidate architectures, through accurate comparison criteria. The result of the trade-off confirms the architecture feeling and states the optimized architectures, for achieving the five propulsion functions, with a solid propulsion add-on system. Finally, as an architecture illustration, the related placements on the satellite body and the corresponding performance specifications are given for each propulsion function. c) Technological solid propulsion study (WP 3100) [7] : From the previously defined performance specifications for the five identified applications, the suitable technological solid propulsion solutions (cluster of solid motors) are sized and designed with respect to operational requirements : particle emission free propellants, limitation of acceleration for satellite integrity purpose. Then, the followed specifications of the solid motors that could be used for each application, are stated and the related solid motors designed. As examples, four satellite platforms types are considered for illustration in order to give an overview of what the solid propulsion would imply in terms of installation on a satellite. Finally, considerations on technological and industrial aspects of solid propulsion complete this study, which show that the development & qualification of such solid motors, for achieving the five selected satellite propulsion applications, are affordable, without technical risks, while the time to market is no more than two years. 2) References [1] [2] [3] [4] [5] [6] ESTEC/Contract No.14818/00/NL/PA, European Space Agency, 10/01/01 Schöyer H.F.R., Some Considerations on the Use of Solid Propellant De-orbiting Motors, ESTEC, Sept. 98 Dubuisson M., General Specifications for the Using of Solid Propulsion for Spacecrafts, PyroAlliance, Document DT/D/S MDU n°49, 14/11/00 Bullock M., Assessment Study on the Application of Solid Propulsion to Satellites-Work Package 1200 Mission Analysis, PyroAlliance-Bertin Technologies, Document n° 01-0031/H, 31/01/01 Bullock M., Assessment Study on the Application of Solid Propulsion to Satellites-Work Package 2100 Architecture Definition, PyroAlliance-Bertin Technologies, Document n° 01-0426/H, 31/05/01 Bullock M., Assessment Study on the Application of Solid Propulsion to Satellites-Work Packages 2200 & 2300 - Trade-off & Architecture Optimization, PyroAlliance-Bertin Technologies, Document n° 395-001-DE001-A, 03/08/01 Martin P., Assessment Study on the Application of Solid Propulsion to Satellites-Work Package 3100 Technological Study, PyroAlliance, Document DT/E/01032, 03/09/01 [7] This document is the property of PyroAlliance - Propulsion Division - SNPE Group. Its contents shall not be disclosed. ? PyroAlliance - Propulsion Division - SNPE Group - 2001. Les Mureaux, 07/09/2001 Note PADC 129/01 A 0 Page 3 / 7 Direction Commerciale et Marketing 3) System study : mission analysis Satellite missions The satellite mission can be defined by the application and the working orbit. Typical combinations include: ??Telecommmunications and broadcast satellites in GEO and HEO ??Telecommmunications satellite constellations in LEO and GEO ??Earth Observation satellites (weather, imaging, remote sensing) in GEO and in LEO (and in LEO-SSO) ??Science satellites (astronomy and fundamental physics) in LEO, HEO and interplanetary orbits ??Navigation satellites in MEO The above mentioned working orbits can be defined as follows: ??GEO: Geostationary Orbit (altitude: 35786 km, inclination: 0°) ??HEO: Highly Elliptical Orbit (ex. Tundra orbit, perigee: 24388 km, apogee: 47097 km, inclination 64?) ??LEO: Low Earth Orbit (altitude lower than 1500 km) ??LEO-SSO: Sun-synchronous or near Sun-synchronous, (ex. altitude of 800 km, inclination 98.6°) ??MEO: Medium Earth Orbit (altitude between than 10000-25000 km) Launch possibilities Mission Telecom - GEO Telecom - LEO EO -LEO Navigation - MEO Induced requirements : orbit insertion Main Launch Vehicles – 2002/2003 Ariane 5, Atlas 3 or 5, Proton M(-Breeze M), Zenit Delta 2 and 3, Soyouz, Rockot Soyouz, Rockot, Delta 2 and 3, Kosmos Ariane 5,Proton, Soyouz Table 3.1 Launch vehicles to be considered as a function of satellite mission Propellant Mass/ Geosynchronous ?V Satellite Mass (Isp=290s) Transfer Orbit (km/s) 0,40 1,45 700 x 35940 km, 7? 35786 km, 0? 0,40 1,45 220 x 45300 km, 17? 0,40 1,47 250 x 35700 km, 0? 0,37 1,32 5500 x 35940 km, 17? 0 0 35700 km, 0? Table 3.2 Estimated energy (? V) required to achieve near GEO with different launch vehicles Final Orbit 23220 km, 54? Propellant Mass/ Main Launch Geosynchronous ?V Satellite Mass (Isp=290s) Vehicles Transfer Orbit (km/s) Ariane 5 1,39 0,39 700 x 23220 km, 54? Soyouz 1,39 0,39 700 x 23220 km, 54? Proton (ILS) 0,89 0,27 7000 x 23220 km, 54? Proton –Breeze M (ILS) 0 0 23220 km, 54? Table 3.3 Delta V requirements to achieve MEO from the defined transfer orbit Launch Vehicles Transfer Orbit Final Orbit Main Launch Vehicles Ariane 5 Atlas 3B Sea Launch Zenit Proton Proton –Breeze M Propellant Mass / Satellite Mass ?V (Isp=290s) (m/s) 1470 km, 53° Soyouz 940 km, 53° 250 0,08 Delta 940 km, 53° 250 0,08 Table 3.4 Estimated energy (? V) required for transferring a LEO (Skybridge) satellite into working orbit Space environment The space environment defines the working environment. Key space environment considerations for the spacecraft propulsion design include : ??vacuum conditions ??temperature range and cycling ??eclipses ??debris ??radiation and atomic oxygen . Final Orbit This document is the property of PyroAlliance - Propulsion Division - SNPE Group. Its contents shall not be disclosed. ? PyroAlliance - Propulsion Division - SNPE Group - 2001. Les Mureaux, 07/09/2001 Note PADC 129/01 A 0 Page 4 / 7 Direction Commerciale et Marketing Propulsion needs The goal of this section is to provide an overview of the propulsion needs for the selected satellite missions. The propulsion needs that are considered are the following: ??Orbit Injection: transfer between launch vehicle separation orbit and the working orbit ??Orbit Placement: fine corrections to place satellite into its operating position ??Orbit Maintenance: fine corrections to maintain an operating position ??Attitude Control ??End-of-life De-orbiting The following Table provides an overview of the needs. As shown in this Table, the needs for propulsion vary in size (in force and in length) and in burn type (continuous and pulse bits). Propulsion Need Orbit Injection Application (Transfer) Telecom/GEO 1300-1500 m/s (? 1 burn) Orbit Placement ? V Budget : 10 to 20 m/s 0.1- 6 m/s/burn 4 to 10 burns similar as above Orbit Maintenance (Station keeping) Inclination (N/S) 3-6 m/s/burn; monthly Semi-major axis 0,1-0,5 m/s/burn; monthly above 1200 km: 1-30 mm/s/burn 3-6 burns/year Attitude Control De-orbiting or re-orbiting 11 m/s (? 2 burns) 300 km orbit raising < 1x 107 pulses (mainly 10-20 ms) weekly or monthly or for specific operations 230-360 m/s Telecom/LEO 150-250 m/s < 1x 106 pulses perigee reduction to (mainly 10-20 ms) (? 2 burns) 60 km weekly or monthly or for specific operations from 900 - 1460 km 140-220 m/s < 1x 106 pulses similar as around 600-800 km EO/LEO separation orbit perigee reduction to (mainly 10-20 ms) above 5-100 mm/s/burn (SAR and optical) is near working 60 km weekly or monthly or bi-weekly to bi-monthly orbit for specific operations from 550 - 850 km 18,5 m/s < 1x 106 pulses Navigation/MEO 900-1400 m/s similar as To be determined (mainly 10-20 ms) above Assumed to be between 0,1 (? 2 burns) (? 1 burn) weekly or monthly or 300 km orbit raising mm/s to 1 m/s/burn; for specific operations Monthly basis at least 2 burns Table 3.5 Overview of the potential propulsion needs as function of satellite mission Illustration of the thrust versus the burn time, giving the potential application area for solid propulsion (clear grey) 100000 10000 1000 LEO spin-up GEO/MEO insertion - 1 burn LEO GEO/MEO de-orbiting re-orbiting GEO spin-up 7 Tons, 1450 m/s 2 Tons, 1450 m/s Thrust (N) 100 10 1 0,1 0,1 1 10 100 GEO E/W & MEO stationkeeping LEO (550-850 km) orbit maintenance GEO/MEO insertion- 3/4 burns LEO insertion or orbit plane changes GEO N/S stationkeeping 1000 10000 100000 Burn Time (s) Achievable satellite missions & foreseeable applications (propulsion functions) for solid propulsion ?? Telecom / GEO & Navigation / MEO : Orbit insertion – Re-orbiting – Spin-up/-down ?? Telecom / LEO : Orbit insertion & orbit plane changes – De-orbiting (until 60 km) – Spin-up/-down This document is the property of PyroAlliance - Propulsion Division - SNPE Group. Its contents shall not be disclosed. ? PyroAlliance - Propulsion Division - SNPE Group - 2001. Les Mureaux, 07/09/2001 Note PADC 129/01 A 0 Page 5 / 7 Direction Commerciale et Marketing 4) Propulsion subsystem : Architecture – Trade-off Considered Propulsion technologies ?? Liquid Monopropellant: : wide thrust range, modulable, proven / difficult to handle, toxic vapors, low Isp ?? Liquid Bipropellant : wide thrust range, modulable, proven / complex, costly ?? Solid propulsion : large thrust capability, simple, cheap / not low thrust, one thruster per burn ?? Electrical propulsion : large Isp, low thrust capability / complex, power consumption, large maneuver time It appears that the combined propulsion technology :" Electrical + Solid" covers the whole thrust range and will be retained for our purpose. Moreover, such a solution provides a decisive advantage for the cases which require redundancy and independent propulsion technologies. Comparison criteria ?? Global costs : Propulsion Hardware, Production, Integration, Launch (i.e. mass/cost), Operational (Facility and man-time costs for operations) ?? Impact on Satellite Design : Structure, Stabilization requirements ?? Maneuver Duration (insertion, relocation): Impact on degradation (ex. time in Van Allen belt), on operations costs, lost revenue, potential downtime ?? Maneuver Accuracy (insertion, relocation) ?? Volume/Integrability: Volume of satellite versus available volume in the fairing, Integrability of propulsion unit in the satellite ?? Operational Risk Assessment : Dependability, Availability, Reliability ?? Technological Risks (maturity of available technology) ?? Versatility/potential of launch vehicles Trade-off results Application Electrical (only) Electrical + Liquid Electrical + Solid /Mission +: reduced time in +: lowest mass Orbit +: reduced time in radiation belt, versatility -: longest Insertion radiation belt, radiation Tel./GEO global cost -: global cost exposure Nav/MEO -: high thrust, thermal Re-orbiting Tel./GEO Nav/MEO Orbit changes Tel./LEO De-orbiting Tel./LEO +: independent +: lowest mass +: independent system, system, global cost versatility -: potential -: versatility -: global cost concern for reliability +: versatility, 1-2 day +: 1-2 day +: lowest mass manoeuvre time manoeuvre time, -: longest -: global cost global cost manoeuvre time -: versatility, integrity (loss of service) +: lowest mass +: versatility, reduced +: global cost, -: many passes time in other working reduced time in in manned s/c & orbits other working orbits satellite orbits -: global cost -: versatility Electrical (only) Spin-up/ spin-down all missions +: lowest mass -: manoeuvre time Conclusions Solid motor appears to be an attractive low cost solution to bring satellites above radiation belt Points to consider: impact of thrust level on satellite design Solid propulsion may be an interesting low cost solution if satellite operators wish to have an independent solution Solid propulsion may be an interesting low cost solution if satellite operators wish to have a rapid manoeuvre in order to reduce down-time Solid motor appears to be attractive for performing the final de-orbit manoeuvre due to its global cost Points to consider: impact of thrust level on satellite design Attitude Control Electrical + Solid Actuators Solid propulsion may be an interesting low cost +: easy to control +: independent -: manoeuvre time, may system, global cost solution if satellite operators wish to have an need to increase -: versatility, integrity independent solution and/or a rapid manoeuvre actuator size Table 4.1 Summary of trade-off propulsion solutions Architecture definition & placement on satellite body refer to appendix This document is the property of PyroAlliance - Propulsion Division - SNPE Group. Its contents shall not be disclosed. ? PyroAlliance - Propulsion Division - SNPE Group - 2001. Les Mureaux, 07/09/2001 Note PADC 129/01 A 0 Page 6 / 7 Direction Commerciale et Marketing 5) Technological propulsion study Propulsion requirements Application for Solid Propulsion Orbit Insertion Mission/Orbit Telecom/GEO Navigation/MEO Telecom/GEO Navigation/MEO Telecom/ LEO Telecom/ LEO Propulsion system architecture Electrical/ Solid Electrical/ Solid Electrical/ Solid Electrical/ Solid Requirements for Application ?V : 1,45 km/s Msat : 2 - 7 Tons Minimum : 1 burn ?V : 11 m/s Msat : 800 - 2000 kg Minimum : 2 burns ?V : 250-350 m/s Msat : 200 - 1250 kg Minimum : 2 burns ?V : 230-360 m/s Msat : 200 - 1250 kg Minimum : 1 burn Specifications 1) Msat = 2000 kg / ?V = 1450 m/s 2) Msat = 7000 kg / ?V = 1450 m/s 1) Msat = 800 kg / ?V = 11 m/s 2) Msat = 2000 kg / ?V = 11 m/s 1) Msat = 200 kg / ?V = 300 m/s 2) Msat = 1250 kg / ?V = 300 m/s 1) Msat = 200 kg / ?V = 300 m/s 2) Msat = 1250 kg / ?V = 300 m/s Re-orbiting Orbit Plane Change or Orbit Insertion De-orbiting (to an altitude of 60 km) Spin-up/ spin-down All missions Electrical/ Solid 1) GEO beginning of insertion (spin-up) : Msat = 4500 kg / 5 -> 30 rpm 6-25 kNs for GEO insertion 2) GEO end of insertion (spin-down) : Msat = 2700 kg / 30 -> 0 rpm 2-10 kNs for GEO re3) GEO end of life reorbiting (spin-up) : Msat = 1400 kg / 0 -> 30 rpm orbiting 0,5-5 kNs for LEO de-orbiting 4) LEO beginning of insertion (spin-up) : Msat = 700 kg / 0 -> 30 rpm 5) LEO end of insertion (spin-down) : Msat = 700 kg / 30 -> 0 rpm 6) LEO end of life deorbiting (spin-up) : Msat = 700 kg / 0 -> 30 rpm Table 5.1 Considered specifications for each solid propulsion application Solid propulsion main constraints a) Selection of propellants, particle emission free in combustion, such as : ?? Composite propellant : Butalite : d=1.699 – Isp=270s – Combustion velocity=3.8mm/s ?? Homogeneous propellant : SD 1152 : d=1.647 – Isp=290 – Combustion velocity=30mm/s b) Limitation of acceleration and related propulsion thrust, for keeping the satellite integrity during maneuver ?? ? =0.5 g max for applications where appendages are non deployed (orbit insertion) ?? ? =0.04 g max for applications where appendages are deployed (orbit plane change – re-/de-orbiting) c) Limitation of the length of the propellant loading (end burning mode) by the splitting in a full or cylindrical "Cluster" of standard solid motors, successively burning two by two, until the achievement of the propulsion application, thus bringing it some modulation. Definition of the solid propulsion applications, related to four satellite platform examples Satellite Application Spin-up before orbit insertion Orbit insertion ARTEMIS TYPE (GEO / 3.1 T / 1.24 T) Spin-down after orbit insertion Spin-un before re-orbiting Re-orbiting JASON TYPE (LEO / PROTEUS / 0.5 T / 0.46 T) SKYBRIDGE TYPE (LEO / 1.25 T / 1.2 T) Spin-up before de-orbiting De-orbiting Combination : Spin-up +Orbit plane change or insertion + Spin-down Combination : Spin-up + orbit insertion + Spin-down Configuration of the motors 2 clusters of 3 solid motors 1 cylindrical cluster of 14 solid motors 2 clusters of 3 solid motors 2 clusters of 3 solid motors 1 cluster of 4 solid motors 2 clusters of 2 solid motors 1 cylindrical cluster of 12 solid motors 1 cylindrical cluster of 12 solid motors : 4 motors (+ 4,6°) : spin-up + thrust 4 motors ( 0°) : thrust only 4 motors (- 4,6°) : spin-down + thrust 1 cylindrical cluster of 14 solid motors : 4 motors (+ 0,6°) : spin-up + thrust 6 motors ( 0°) : thrust only 4 motors (- 0,4°) : spin-down + thrust 2 clusters of 3 motors 1 cluster of 4 motors Dimensions of each motor (mm) diameter : 36 length : 200 diameter : 265 length : 975 diameter : 30 length : 240 diameter : 24 length : 235 diameter : 67 length : 206 diameter : 15 length : 120 diameter : 85 length : 425 Diameter : 140 Length : 345 Specifications Propellant : SD Combustion : end burning Propellant : SD Combustion : end burning Propellant : SD Combustion : end burning Propellant : SD Combustion : end burning Propellant : SD Combustion : end burning Propellant : SD Combustion : end burning Propellant : BUTALITE Combustion : end burning BUTALITE End burning ASTRA TYPE (GEO / SPACEBUS 3000 / 5.25 T / 3.1 T) Diameter : 345 Length : 975 Diameter : 37 Length : 220 Diameter : 105 Length : 203 SD End burning SD End burning SD End burning Spin-up before re-orbiting Re-orbiting Table 5.2 Solid propulsion applications : orbit insertion – re- / de-orbiting to platforms examples This document is the property of PyroAlliance - Propulsion Division - SNPE Group. Its contents shall not be disclosed. ? PyroAlliance - Propulsion Division - SNPE Group - 2001. Les Mureaux, 07/09/2001 Note PADC 129/01 A 0 Page 7 / 7 Direction Commerciale et Marketing - APPENDIX Propulsion architecture definition for Telecom / GEO & Navigation / MEO Propulsion function needs Orbit Insertion Orbit Maintenance Re-orbiting Solid to pass radiation belt Electric to complete orbit transfer & to place in mission orbit Electric for N/S and E/W station keeping Electric or solid (if independent system is required) Placement on satellite body (GEO & MEO) Z axis (yaw) (Earth pointing) Y axis (pitch) (South) X axis roll Dir. of motion Solid motor – insertion Solid motor – re-orbiting Electric Propulsion Propulsion architecture definition for Telecom / LEO Propulsion function needs Orbit Insertion Orbit Maintenance De-orbiting Electric or Solid to make orbit transfer Electric to place in mission orbit Electric for orbit maintenance Electric to place in transition orbit Solid to place into a capture orbit Placement on satellite body (LEO) Z axis (yaw) (Earth pointing) Y axis (pitch) X axis roll Dir. of motion Solid motor – de-orbiting Solid motor – insertion This document is the property of PyroAlliance - Propulsion Division - SNPE Group. Its contents shall not be disclosed. ? PyroAlliance - Propulsion Division - SNPE Group - 2001.