Docstoc

ASTROD2006-Heinzel.ppt - Wikispaces

Document Sample
ASTROD2006-Heinzel.ppt - Wikispaces Powered By Docstoc
					    Third International ASTROD Symposium, Beijing
                       14 July 2006




               LISA Pathfinder


        A Technology Demonstrator for the
     LISA Space Gravitational-Wave Detector

Gerhard Heinzel and Albrecht Rüdiger, AEI Hannover
LISA Pathfinder


                             Thanks
First I would like to convey Gerhard Heinzel‘s regret
        that he cannot be here today: urgent other commitments
My talk will draw to a major extent on Gerhard’s notes
Next, I would like to express my thanks for the invitation
  to come to Beijing for this
Third International and First Sino-German ASTROD Symposium,
    this one again in Beijing as the memorable first one in 2001
It fills me with joy to meet many „old“ friends and colleagues,
    and to make new acquaintances, and I am again overwhelmed
          by the friendliness and helpfulness of the organizers
                          6th International LISA Symposium
LISA Pathfinder


Sequence of talks on LISA, LISA Pathfinder

It is unfortunate that my talk on the LISA Pathfinder precedes
    Oliver Jennrich‘s talk on LISA, to be held tomorrow
May I, not to overload my talk with the details of LISA,
  just assume LISA to be sufficiently known to most of us
       and plunge into discussing its Technology Demonstrator
Tomorrow will then give you the latest news on LISA,
  from the person most competent on it: Oliver Jennrich




                        6th International LISA Symposium
      Third International ASTROD Symposium, Beijing
                         14 July 2006




                 LISA Pathfinder


An ESA-Nasa project to test certain technological
                    aspects of
       the full-sized LISA GW detector:
      Third International ASTROD Symposium, Beijing
                         14 July 2006




                 LISA Pathfinder


An ESA-Nasa project to test certain technological
                     aspects of
        the full-sized LISA GW detector:
 Two free-floating test masses in one spacecraft
LISA Pathfinder




                  6th International LISA Symposium
LISA Pathfinder

Interferometry on LISA Pathfinder: two free-floating test masses




           Multiple interferometry using heterodyne Mach-Zehnder to measure:
           relative distance, displacement, relative beam phase, laser frequency

                                              6th International LISA Symposium
LISA Pathfinder




                   Injection into orbit near L1 Lagrange point
                  with sequence of apogee-raising rocket firings
                             6th International LISA Symposium
LISA Pathfinder


LISA Pathfinder
        After initial study, SMART-2 was descoped and renamed LISA
        Pathfinder
          – Darwin Pathfinder removed from mission
          – Single spacecraft with two payloads:
                  • European provided LTP
                  • NASA provided DRS
          – Both payloads comprised*:
                  •   Two inertial sensors
                  •   Laser metrology
                  •   Micro-Newton Thrusters
                  •   DFACS
          – Orbit: Lissajous orbit around L1
          – Launch Vehicle: Rockot
          – Launch date: 4th Qtr 2009


          *The inertial sensor and laser metrology
          have now been descoped from the DRS

                                               6th International LISA Symposium
LISA Pathfinder


Mission Goal [1]

            The primary goal of LISA
            Pathfinder is to verify that a
            test mass can be put in
            pure gravitational free-fall
            with residual acceleration
            noise less than
                                              f 2  2
                      f   3  10
             1
                                      14
           Sa    2
                                            1          ms   Hz
                                            
                                                 3mHz  
                                                          

            over a frequency range
            of 1-30mHz




                                                          6th International LISA Symposium
LISA Pathfinder


Mission Goal [2]

         A secondary goal, which
         has now become directly
         relevant to LISA, is to
         demonstrate laser
         metrology using free
         floating mirrors with a
         displacement sensitivity of

           1                 3mHz  2 
        Sx2                     f  m
                9  1012 1              Hz
                            
                                     

         over a frequency range of
         1-30mHz



                                            6th International LISA Symposium
LISA Pathfinder


Proof Mass
           Procured from Heraeus, Germany
                                                                   Raw
           46mm cube of Gold-Platinum                              Material
            – 73% Au:27%Pt
           Mass = 1.96kg
           Indentation on top and chamfered
           corners for caging mechanism
                                                                   Polished
           Similar to LISA test mass
            – Magnetic Susceptibility requirement
              relaxed by one order of magnitude

           “A sensitive Torsion Balance for LISA
           Proof Mass Testing”,                                    Polished
                                                                   and Coated
           Stephen Schlamminger, Tuesday, 16:50

                                6th International LISA Symposium
LISA Pathfinder


Inertial Sensor Ground Testing

           Inertial sensor cannot be fully tested on ground
            – Hence the need for LISA Pathfinder
           Ground testing focussed on torsion pendulums

           Dedicated torsion pendulums constructed at the University
           of Trento
           Noise in torsion pendulum approaching that of LISA
           Pathfinder!!
            – Only in one axis
            – Light-weighted proof mass
            – Cannot fully represent cross-coupling


                                 6th International LISA Symposium
LISA Pathfinder


Micro-Newton Thrusters
           Micro-Newton thrusters for LTP based on Field Emission
           Electric Propulsion (FEEP)
           Two developments underway in Europe
            – ALTA: Caesium FEEP
            – ARCS: Indium FEEP
           After first phase of development, down-select will be made
           between the two thruster architectures
            – This design will be taken to flight hardware




                                 6th International LISA Symposium
LISA Pathfinder




                  6th International LISA Symposium
LISA Pathfinder


LTP Integration: how it’s put together




                  6th International LISA Symposium
LISA Pathfinder




                  6th International LISA Symposium
LISA Pathfinder




                  6th International LISA Symposium
LISA Pathfinder




                  6th International LISA Symposium
LISA Pathfinder




                  6th International LISA Symposium
LISA Pathfinder




                  6th International LISA Symposium
LISA Pathfinder


LTP Core Assembly




                  6th International LISA Symposium
LISA Pathfinder

      Schütteltest Optische Bank




                   6th International LISA Symposium
LISA Pathfinder


Launch Vehicle
        Baseline launch vehicle: Rockot
          – Procured from Eurockot, Bremen
          – Breeze KM upper stage
          – Proven vehicle with heritage
                  • SS19 ICBM!
          –   Launch from Plesetsk, Russia (latitude 63o)
          –   Injection into 200x900 km orbit
          –   Max lift-off weight of S/C: 1910 kg
          –   Facility to be upgraded for bi-propellant
              fuelling (vapour traps, waste disposal, etc)




                                   6th International LISA Symposium
LISA Pathfinder


Launch Vehicle

           Target launch vehicle is VEGA
            – Procured from Arianespace
            – New launcher
                  • LPF could be first flight!
            – Launch from Kourou, French Guiana (latitude 5o)
            – Injection into circular orbit…Check
            – No free injection into L1 Lissajous orbit
                  • Requires injection burn


            – Winter temperature : ~28oC




                                         6th International LISA Symposium
LISA Pathfinder


Launch Sites


           Plesetsk:
           Winter temperature : -30oC!




          Kourou:
          Winter temperature : +28oC!


                             6th International LISA Symposium
LISA Pathfinder


Orbit

           LPF launched into high inclination orbit of 200x900km
           15 apogee raising manoeuvers required to deliver LPF to
           L1
            – High inclination orbit allows free transfer (no orbit insertion
              required)
           Prop module separate
           during transfer phase
           Final orbit is Lissajous
           orbit around L1




                                   6th International LISA Symposium
LISA Pathfinder



Interferometry on LISA Pathfinder: two free-floating test masses




         Multiple interferometry to measure: relative distance, displacement from OB,
         relative beam phase, laser frequency

                                                6th International LISA Symposium
LISA Pathfinder

             Heterodyne measurement of relative distance




                                   6th International LISA Symposium
LISA Pathfinder

                  Displacement with respect to optical bench




                                    6th International LISA Symposium
LISA Pathfinder




                  6th International LISA Symposium
LISA Pathfinder




                  6th International LISA Symposium
LISA Pathfinder



Interferometry on LISA Pathfinder: two free-floating test masses




         Multiple interferometry to measure: relative distance, displacement from OB,
         relative beam phase, laser frequency

                                                6th International LISA Symposium
LISA Pathfinder




                  6th International LISA Symposium
LISA Pathfinder


Optical Bench EM performance




                  6th International LISA Symposium
LISA Pathfinder


Phase-meter performance




                  6th International LISA Symposium
LISA Pathfinder




                  6th International LISA Symposium
LISA Pathfinder


LPF Status

           LPF passed Mission Preliminary Design Review (M-PDR)
           in February 2006
            – M-PDR consolidates the LTP PDR, System PDR, Ground
              Segment Requirements Review, and DRS CDR


            LISA Pathfinder is now in PHASE C/D:
                    Detailed Design Phase




                              6th International LISA Symposium
LISA Pathfinder


LPF Main Reviews/Schedule
          System Requirements Review                            Jun-Nov 2004
          Technology Readiness Review                           22 June 2005
          Preliminary Design Review                             29 September 2005
          LTP Preliminary Design Review                         31 August 2005
          Ground Segment Req Review                             24 November 2005
          DRS Delta-CDR/Risk Review                             20 January 2006
          Mission Preliminary Design Review                     16 February 2006
          LTP Subsys. Critical Design Review                    Q3-Q4 2006
          LTP Critical Design Review                            Q1-Q2 2007
          Critical Design Review                                Q3 2007
          Flight Acceptance Review                              Q4 2009
          Launch                                                Q4 2009

                             6th International LISA Symposium
LISA Pathfinder


LTP Team




                  LTP workshop, Trento 2005

                      6th International LISA Symposium

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:3
posted:3/22/2012
language:
pages:40