HTHGA System TDA by Kongsberg Team TSR Presentation at ESTEC 23 February 05

Transcription

1 HTHGA System TDA by Kongsberg Team TSR Presentation at ESTEC 23 February 05 Aud Fossdal / Johan Mürer WORLD CLASS through people, technology and dedication WORLD CLASS through people, technology and dedication KONGSBERG February 25,

2 TSR Presentation Contents 1. Brief recall of original Objectives of TDA 2. Technology Requirements (confirmation/amendment of the quantitative performance and environmental requirements in SoW and TDA specification) 3. Scope of TDA (as actually run), including an estimate of the achieved TRL 4. Schedule of TDA (if not yet completed by February 2005) 5. Deliverables of TDA (hardware models as actually built, software, key specifications and reports) 6. Critical Technology Requirements not met and performances not achieved by the TDA 7. Critical technology items not covered by scope of TDA (late discovery, limited resources) and assessment of related technological risk 8. Planning to Flight Model status (additional development & qualification activities, required models, required facilities if critical/non-standard, estimated schedule) KONGSBERG February 25,

3 HTHGA Concept 3

4 1. Brief recall of original Objectives of TDA The main objective of this study was to derive at a high temperature (250 C TBC by Contractor), high gain antenna system design, including detailed unit, component, material and process selections. The result should be a mass efficient (20 kg) and feasible concept. TDA completed before start of the BepiColombo realisation phase (early 2003). 4

5 1. Brief recall of original Objectives of TDA The study was primarily aimed at critical technologies by investigation, analysis and design, followed by feasibility demonstrations by sample- and BB testing. It should show that there is a high probability of meeting the functional performance requirements under the severe environmental conditions on the Mercury mission. 5

6 2. HTHGA Technology Requirements Thermal functional requirements, initial in SoW: ARA -150 C to +250 C (TBC) APA, mechanisms: -40 C to +250 C (TBC) Qualification temperature limits established by analysis of Mercury orbit conditions and TCS performance with antenna geometry. D = Cold Case B1 and B2 Max gradient and max temp F = Hot Case 6

7 2. HTHGA Technology Requirements Margins applied: Qualification temperature = Calculated +40 K / -30 K White paint EOL sun absorption; alpha = 0,35 Qualification upper temperatures: ARA reflector: 345 C ARA sub-reflector: 359 C APM structure/bearing: 264 C (elevation stage) APM motor: 289 C (elevation stage) APA Boom: 261 C APM Azimuth: 113 C 7

8 2. HTHGA Technology Requirements ARA temperature performance: ARA resin (Cyanate Ester RS9D), max 287 C (Supplier recommended). Significant out-gassing encountered in sample tests with RS9D. The considerable increase of temp above 250 C made RS9D too high risk for ESA to continue the Phase 2 of TDA. Final optimized performance of RS9 combined with potential identified improvements in thermal conditions, is therefore not verified. 8

9 2. HTHGA Technology Requirements APA temperature performance 2 axis APM with integrated Ka- and X-band RF Rotary Joint. High temperature composite boom. Life tested bearing lubrication program performed at 250 C, with about 20% additional cycles in temperature steps at 275 C and 300 C. Lubrication performance verified, final cage material to be confirmed. High temperature solder material chosen for motor (eutectic melting point at 310 C) combined with dry lubrication in bearings and gears. Mechanisms materials mainly Titanium alloy and Stainless Steel capable of temperature and well matched for minimum thermal deformations. 9

10 2. HTHGA Technology Requirements Mass required < 20 kg (not incl. margin and drive electronics) Mass budget w/ light weight composite sandwich reflector: -APA (incl. 2 APM s w/rj s, Boom, WG s, HDRM, MLI) -ARA (incl. Ø2 m reflector, WG s, Dual band horn, MLI) -Total with phase 1 light weight reflector 12,2 kg 9,1 kg 21, 3 kg 10

11 2. HTHGA Technology Requirements Radio Science Experiment Antenna Requirements Equivalent electromagnetic path length variation over 1000 seconds, one way: Ka-Ka less than: 0.9 mm; HTHGA worst case: 2.6 mm X-X less than: 3.6 mm; HTHGA worst case: 5.9 mm X-Ka less than 9 mm; HTHGA worst case: 2.5 mm 11

12 2. HTHGA Technology Requirements Mechanical performance Pointing Accuracy -APM required: 0.01 half cone. APM analysis main conclusion: -Pointing accuracy within 0.01, but average value biased due to: Electrical lag, pending friction; about Gear backlash, pending drive direction; about Antenna first bending mode gives pointing disturbance. 12

13 2. HTHGA Technology Requirements Mechanical performance Max pointing rate and acceleration, requirements: -Antenna re-orientation speed; 2 deg/s max accel; 1 deg/s2 -Antenna pointing, rate; 0,2 deg/s accel; 0,1 deg/s APM predicted to meet the requirements. 13

14 2. HTHGA Technology Requirements Mechanical performance Pointing Accuracy example Speed 0.05 deg/s Angle [deg] Time [s] 14

15 2. HTHGA Technology Requirements Mechanical performance Disturbance torque req. < 0.05 Nm in pointing mode. Analysis: Disturbance pending start conditions (avoid antenna bending oscillations) and speed. Speed 0.05 /s, disturbance < 0,03 Nm. Speed 0.2 /s, disturbance > 0,35 Nm. 15

16 2. HTHGA Technology Requirements RF Performance: Gain Req. Perf. w/ dual band horn (1.5 m) X db 36.8 db X db 38.2 db Ka db 49.6 db Ka db 50.0 db APM RF loss (unit spec): Ka band: -0,4 db X band: -0,12 db 16

17 2. HTHGA Technology Requirements RF Performance: Return Loss (VSWR), required < -25 db Predicted worst case for complete system: 12 db (pending final system design and analysis). PIMP; not considered due to assumed single carrier frequency. Cross polarisation < -25 db, pending new reflector and Horn. 17

18 2. HTHGA Technology Requirements Life requirement 5.5 years in space, more than 1+1 years in Mercury orbit / nominal cycles. Lubrication tested to more than cycles at temperature. White paint thermo optical performance (alpha < 0.35) open point. 18

19 2. HTHGA Technology Requirements Stiffness requirement (first eigen frequency): -Stowed: > 50 Hz. -Deployed: > 2,5 Hz Analysis of HTHGA design with light weight composite antenna: -Stowed: -Deployed: > 81 Hz. > 4,6 Hz 19

20 2. HTHGA Technology Requirements Launch loads; 25-g static, three orthogonal directions. Load analysis of HTHGA design yields acceptable loads for HDRM and APM s. Final verification pending new antenna design (probably increased mass, putting loads mainly into HDRM s). 20

21 3. Scope of TDA Complete pointing assembly designed in 3D with Azimuth/Elevation-APM and Boom structure. APA includes Hold Down & Release between antenna and Space Craft panel. Design developed by: APM by Kongsberg Defence & Aerospace. RF Rotary Joint by BAE Systems. Boom structure, Thermal Control System and Hold-Down&Release by Dutch Space. 21

22 3. Scope of TDA Antenna Pointing Mechanism (APM) Design Status 2D manufacturing drawings complete for elevation APM. Assembly procedure for APM and integration of RJ. Design covers an Elevation APM and includes: - Structure with main elements: Housing, Shaft and 90 deg bracket. - Motor and gear drive chain. - Main bearing. - Mechanical end stops and latch override for Stowed mode position. - Mechanical interfaces. 22

23 3. Scope of TDA Antenna Pointing Mechanism (APM) Analysis Antenna Status Pointing Mechanism (APM) Analysis Status Mass budget. Torque budget. Detailed thermal analysis by FEM by use of global model constraints. Thermal distortion. Stiffness/stress. Fit tolerance and bearing stress. End stop shock and loads. Drive performance and disturbance torque. 23

24 3. Scope of TDA Antenna Pointing Mechanism (APM) Test Status on Samples Ball bearing lubrication test program completed at ESTL: Three types lubrication systems evaluated and tested. One system chosen and tested successfully in vacuum at elevated temperature for more than one life. Both RJ support bearing and APM Main Bearing tested. Test performed in vacuum at 250 deg C for oscillations. Additional 2000 oscillation performed at each 275 deg C and 300 deg C. 24

25 3. Scope of TDA Antenna Pointing Mechanism Test Status on APM Breadboard Detailed Test Plan established, PDR and CDR deliverable. Air tests will include: Mechanical friction, detent and static torque and stiffness characterisation. Electrical grounding and dielectric resistance. Functional (pointing) and RF performance. Vacuum tests: Thermal cycling between hot and cold Functional and RF performance. Life cycles. 25

26 3. Scope of TDA Rotary Joint Design Status 2D manufacturing drawings completed. Manufacturing procedures established. Manufacturing facilities established (procedures, cost and schedule). Tooling prepared. Bearing and lubrication system tested. Bearings procured. Thermal cycling tests on Titanium Waveguide piece with plating performed. 26

27 3. Scope of TDA Boom Structure Design Status 2D manufacturing drawings completed Manufacturing tools design for CFRP tube established and manufactured Strength and stiffness analysed Sample tests performed on chosen CFRP system. 27

28 3. Scope of TDA Thermal Control System Thermal Control Systems studied and concept chosen. Thermal Analysis performed for complete Antenna System. (To be updated for new reflector) Operational limits and qualification temperatures established for all major components of the APA 28

29 3. Scope of TDA HDRM Design Status Concepts studied and preferred solution chosen. Loads studied. No hardware or tests were planned in present Study. 29

30 3. Scope of TDA ARA Design Status ESA ITT, Proposal and KO Max temp was assumed to be 250 C (tbc by Contractor) Baseline was Cyanate ester resin RS-9D Max temp has gone beyond 250 C considerably Supplier stated max 287 C for the RS-9D material Extensive material testing performed in Phase 1 to find suitable materials for the increased temperature. Introduced a CCN, to give a more information about the material baseline, RS-9D The result of the technical evaluation by ESA of the proposed technology development for RS9D is that there is not sufficient confidence that this technology would achieve the required performance. ESA has decision was therefore not to proceed with the phase 2B. A new, open, ITT will be issued for the ARA 30

31 4. Schedule of TDA Phase 2 of TDA for APA and new ARA 31

32 5a. Deliverables of TDA HW BB of Elevation stage APM includes: X and Ka band RF Rotary Joint. Drive chainwithhightemperaturelubrication Dummy Position Sensor. No electrical signal transfer (Twist Capsule). BB of ARA is TBC pending open ITT for a new high temp design. 32

33 5b. Deliverables of TDA Major Documents Item No Description Time TN1.1 HTHGA Overall Antenna System Requirement Specification CSR TN1.2 HTHGA Requirement Review and Configuration Selection CSR TN1.3 HTHGA Design Report PDR TN1.4 HTHGA Equipment Requirement Specifications PDR TN1.5 HTHGA Interface Control Document PDR TN1.7 HTHGA Design Data Package CDR TN1.8 HTHGA Test Plan / Requirement at Integrated Antenna Level CDR TN1.9 HTHGA Design and Development Plan FDR TN4.5 APA BB Design Data Package CDR TN4.3 APA Materials and Processes Sample Test Report PDR TN4.4 APA Breadboard Test Plan PDR TN4.6 APA BB Test Report and Design Update FDR TN2.3 ARA Materials and Processes Sample Test Report PDR TN2.4 ARA Breadboard Test Plan PDR TN2.5 ARA BB Design Data Package CDR TN2.6 ARA BB Test Report and Design Update FDR 33

34 6. Critical Technology Requirements not met and performances not achieved by the TDA Mass 20 kg: RSE Expected to have been met with a composites reflector Requirement changed due to new reflector ITT Phase shifts outside RSE requirement are mainly due to Wave Guides in metal (invar or titan). Intended ESA study for high temp, high stability WGs and feeds. RF Gain, TBD with new reflector design. 34

35 7. Critical technology items not covered by scope of TDA Thermal Control System White paint (Based on Bepi system level activity): -Radiation (UV) and temperature aging tests needed for verifying EOL alpha values. -White paint adhesion to MLI. May prove difficult (brittle paint). Verification of physical MLI coverage of APM for Breadboard. Demonstration of MLI attachment methods and performance. 35

36 7. Critical technology items not covered by scope of TDA Position sensor Dedicated position sensor not required, but design is made compatible with potential implementation of it. Presently, angular position is known by motor step count. In case dedicated position sensor would be required, an additional activity (with limited technological activity) shall be foreseen Close contact with Inductosyn in US is established in parallel with the BB design. 36

37 7. Critical technology items not covered by scope of TDA Twist Capsule for el. signal transfer. May be needed if position sensor is included in the APM design. Possible antenna signals (thermistors). Close contact with Mecanex is established for a high temp Twist Capsule for the elevation stage. Azimuth stage = lower temp and not driving the requirements. Delta activity with breadboard manufacture and test needed. 37

38 7. Critical technology items not covered by scope of TDA Complete BB of HTHGA structure and system verification: New reflector may introduce need for design update of APA Overall RFC performance (WG s choke gaps, etc). 38

39 7. Critical technology items not covered by scope of TDA Other potential delta activities identified: Possible modification of drive system for increased pointing accuracy and/or reduced disturbance torque. Establishment of ground test conditions of APM in air (air moisture incompatibility with dry MoS2 lubrication). N2 flush system. Azimuth APM design details. 39

40 8. Planning to Flight Model status Design phase PDR (T0 + 7 mns) Development models (TBC) Structural Model (STM), 2 APMs boom and ARA (T mns) Engineering Model (EM), elevation stage for APM (T mns) Qualification Model (QM) (T mns) Flight Model (FM), (T mns) Flight Spare (FS), EQM refurbished 40

41 WORLD CLASS through people, technology and dedication WORLD CLASS through people, technology and dedication KONGSBERG February 25,