1. Tracker Thermal Control System 1 AMS Tracker Thermal Control System (TTCS) Phase II Safety Presentation SRII meeting, 21 May 2007, Houston Johannes van Es/NLR

2. Tracker Thermal Control System 2 TTCS Objective TTCS System Overview TTCS Components TTCS operational results Contents

3. Tracker Thermal Control System 3 TTCS System Overview 144 Watts

4. Tracker Thermal Control System 4 Provide accurate temperature control of AMS Tracker front-end electronics Keep heat away from the Cryogenic System and Magnet TTCS Objective

5. Tracker Thermal Control System 5 Two independent redundant CO 2 two-phase pumped loops –Primary loop TTCB Box on Port side Condenser at Wake and RAM radiator (also port side) –Secondary Loop TTCB Box on Starboard side Condenser at Wake and RAM radiator (also starboard side) –TTCE Tracker Thermal Control Electronics located at the wake radiator bottom next to PDS TTCS Overview

6. Tracker Thermal Control System 6 TTCS box envelopes (locations) Tracker radiators TTCS Condensers are attached to the Tracker radiators Tracker

7. Tracker Thermal Control System 7

8. 8

9. 9 All components except the evaporator and the condenser are located in the TTCS-box –one primary box (port side) –one secondary box (starboard side) Containing –Pumps (2x) –Accumulator with Peltier heat exchanger –Heat Exchanger with start-up heaters –Absolute pressure sensors (2x) –Differential pressure sensors (2x) –Cold orbit heater (1 unit) –Pre-heaters (2x) –Thermal switches (20x) –Pt1000 temperature sensors (30x) –Dallas temperature sensors (22x) Box components

10. Tracker Thermal Control System 10 Tracker Thermal Control System Evaporator (overview) 192 Hybrids each producing 0.75 Watts of heat (144 W total)

11. Tracker Thermal Control System 11 Tracker Thermal Control System Evaporator (overview)

12. Tracker Thermal Control System 12 Tracker Thermal Control System Evaporator tubing upper inner and outer ring Connection to transport tubing

13. Tracker Thermal Control System 13 Welding close to TTCS boxes Tracker Thermal Control System TTCS Boxes

14. Tracker Thermal Control System 14 weld locations indocated with arrows TTCS Primary Box location (wake port side)

15. Tracker Thermal Control System 15 Tracker Thermal Control System TTCS Condenser locations

16. Tracker Thermal Control System 16 TTCS Primary loop Wake Condenser (WAKE port side) Each system has two condensers one on Wake side and one on RAM side

17. Tracker Thermal Control System 17 RAM WAKE PORT side STARBOARD side Primary loop TTCS tubing on port side

18. Tracker Thermal Control System 18 RAM WAKE PORT side STARBOARD side Secondary loop TTCS tubing on starboard side

19. Tracker Thermal Control System 19 Each independent loop includes the following components the loop box: 2 redundant pumps 1 Accumulator to –accommodate liquid in case of two-phase operation and to allow for temperature-volume changes –control the evaporation temperature in the evaporator by control heaters, Peltier elements and emergency heaters Heat Exchanger to use the evaporator heat to pre-heat the subcooled CO 2 fluid (saves power) 2 Pre-heaters to heat both evaporator branches to T saturation TTCS System summary box components

20. Tracker Thermal Control System 20 Absolute pressure sensors to monitor the pressure Differential pressure sensors to monitor the mass flow Cold orbit heater used to increase energy content of the CO 2 two-phase flow. To avoid too low temperatures in cold orbit condition operation Start-up heater to heat the liquid flow to the evaporator from -40C to -20C to keep front-end electronics in their temperature window TTCS System summary box components

21. Tracker Thermal Control System 21 TTCS Box Cold orbit heater accumulator Heat exchanger Diff. P-sensor Abs. P-sensor Swagelok weld couplings

22. Tracker Thermal Control System 22 Cold orbit heater accumulator Heat exchanger Diff. P-sensor Abs. P-sensor Cover with ext. connectors Swagelok weld couplings TTCS Box

23. Tracker Thermal Control System 23 TTCS Box Cold orbit heater Pump Electronics box Pumps

24. Tracker Thermal Control System 24 Pump is an adapted Martian Exploration rover pump by PDT Centrifugal pump Successful CDR in September 2006 Pump EM Pump Pump Controller

25. Tracker Thermal Control System 25 Two-phase accumulator Heat pipe to heat the accumulator in the centre of the accumulator –Peltiers to cool the accumulator at the mantle the Peltier cold side connected to the liquid line from the condensers Accumulator

26. Tracker Thermal Control System 26 Accumulator HP cross section liquid inlet pipe with mesh

27. Tracker Thermal Control System 27 Mesh Design Spoke design to transport the liquid to the HP Wick Design Fan Mesh to keep the CO2 around the liquid inlet to supply the CO 2 -loop with liquid Fan mesh detail Accumulator Spoke and Fan mesh design Spoke mesh design fan mesh design and liquid inlet HP cross section

28. Tracker Thermal Control System 28 Heat Exchanger QM/FM Heat exchanger Assembly

29. Tracker Thermal Control System 29 Heat Exchanger exists of: –36 stacked heat exchanger plates (Inconel 625) –Two container parts (Inconel 625) with machined tube ends 2 Diff. Pressure Sensor at ones side 4 connections to the loop at the other side –2 heater wires at the mantle –2 brackets to connect to the bottom plate –2 clips to connect HX to the brackets –6 Thermal Switches (integrated later) to avoid overheating the TTCS system HX QM/FM Assembly

30. Tracker Thermal Control System 30 HX QM/FM Assembly

31. Tracker Thermal Control System 31 Pre-heater

32. Tracker Thermal Control System 32 Cold-orbit heater

33. Tracker Thermal Control System 33 TTCS Breadboard Testing Results