FEEP microthrusters experimental developments. F. Ceccanti ALTA 1 BU OOS. All rights reserved 2009, Thales Alenia Space

Transcription

1 FEEP microthrusters experimental developments F. Ceccanti ALTA 1

2 FEEP Missions FEEP Thrusters are being developed for the ESA Lisa Pathfinder mission and the CNES Microscope mission. Thruster development is nearly completed, and the assembly of the LPF FEEP Cluster Assembly (FCA) Qualification Model is ongoing. Manufacturing of FM parts for LPF was also released. Microscope programme is currently on hold, pending completion of thruster development. LISA Pathfinder (ESA Technology demonstration for LISA) Microscope (CNES - Equivalence principle) 2

3 History of FEEP development Concept ESTEC and patent (Bartoli & Von Rhoden) 80 s Development aimed at GEO NSSK application (5 to 10 Fulham (UK) and SEP (F), discontinued New interest for science missions: restart of development and EMITS program at Centrospazio/Alta TRP Development of FEEP thruster Cluster CTP Lifetime demonstration for Lisa and Darwin Microscope mission phase 1 and phase CTP Gaia, interrupted Lisa Pathfinder Phase 1 (Development) and Ph 2 LLI procurement Lisa Pathfinder Phase 2 (equiv. to ph. C/D/E) Microscope Phase 3? 3

4 FEEP development milestones (thruster) 2005 Conclusion of core development of FEEP emitter. NEV ( New Emitter Validation ) Test: 1650 h firing operation, 500 Ns total impulse First tests of a fully integrated thruster (Thruster Unit + Tank + Cover), TAEM ( Thruster Assembly Engineering model ) Tests #1, #2 and # Improvement and validation of flight design of emitter: EVT ( Emitter Validation Test ) #1 to #7. Verification of capillary and priming features Verification of Priming and performance: TA Priming Tests #1 to #3. Endurance testing: ET #1, >700 h firing, ~250 Ns; ET#2, >3200 h, ~1000 Ns. Vibration testing on FCA Development Model Thermal Balance Testing on FCA Development Model Direct Thrust Measurement: DTM Test TAS-I Torino Neutral Flow measurement: LIF ONERA Palaiseau 2009 Subsystem Neutralization ESTEC 4

5 FEEP system development milestones (other equipment) 2003 ESA contract for FEEP PCU development (TRP): Galileo Avionica (Milano) 2005 ESA contracts for equipment developments: Propellant Reservoir (Tank): EADS Astrium SAS (Toulouse) Cover Lid mechanism (LOM): Oerlikon Space AG (Zurich) Neutralizer: Thales Alenia Space Italia (Firenze) 2006 Tank PMD verification (Neutral Buoyancy Test) 2007 LOM Qualification Review Coupled PCU-thruster verification 2009 Neutralizer Qualification Review and early Lifetest results LOM Delta Qualification Review (Thermal Kit) Tank Qualification Review LPF PCU CDR 5

6 Achievements of development phase During thruster Development Phase, the following results were achieved: demonstration of priming principle and repeatability (7 thrusters in a row were successfully activated and fired) full performance characterization demonstration of endurance up to more than 1000 Ns (> 3200 hours firing) successful performance of environmental testing (sine + random vibration, thermal balance) direct thrust measurement, characterization of noise and resolution neutral flow measurement characterization (and derivation of mass flow model) verification of subsystem operation (PCU + thruster + neutralizer) and neutralization concept 6

7 Lisa Pathfinder qualification activities In the upcoming Qualification Phase ( ), the following activities will be performed: full qualification at FEEP Cluster level: reduced functional test, vibration, shock, thermal vacuum, full functional test; life test aiming at 1100 Ns target (with possible extension to 1800 Ns or more) full EMC/EMI testing, with RE/RS and AC Magnetic tests performed at The Aerospace Corporation, USA ESTEC and DC ASU Stevenage) subsystem level testing, involving two thrusters, one neutralizer and one PCU, performed at ESTEC, NL. 7

8 Delta development for GG Application of FEEP to GG mission requires: minor modifications to PCU, to increase step response performance; redesign of propellant reservoir to comply with the centripetal acceleration, reducing hydrostatic pressure on emitter tip; tailored design of cluster (thrust directions). 8

9 a few images 9

10 Images Emitter during leak testing ( bubble test ) 10

11 Images Emitter 150 µn. Side view (top) and close-up of emitter slit (bottom) 11

12 Images Measurement of maximum thrust margin: > 500 µn at maximum available total voltage 12

13 Images Tank filling (left) and sealing disk after rupture (right) 13

14 Images Phases of thruster assembling in glove box 14

15 Images 15 Thruster priming

16 Images 16 Direct Thrust TAS-I Torino

17 Images 17 LPF FEEP Cluster Assembly (partially dismounted)

18 Images 18 LPF FCA DM Vibration Testing

19 Images 19 LPF FCA Thermal Balance Testing

20 Alta S.p.A., Via A. Gherardesca 5, Ospedaletto, Pisa, Italy 20