Other Flight Pressure Systems

Phase III Flight Safety Review12 Jan 2009

Flight Pressure Systems

In addition to the magnet cryosystem, AMS-02 has four additional flight pressure systems– Transition Radiation Detector (TRD) Gas Supply– Warm Helium Gas Supply– Thermal Control System– Tracker Thermal Control System (TTCS)

TRD Gas Supply and Warm Helium Supply include Composite Overwrapped Pressure Vessels (COPVs).

TRD Gas Supply

Transition Radiation Detector uses a mixture of Xenon and carbon dioxide gas to identify incoming particles.

System is divided into three major regions– Box S: The primary gas supply, contains all the high-

pressure elements.– Box C: The circulation box, contains the pumps used

to circulate gas through the detector.– TRD: Within the detector itself, gas flows at low

pressure through a series of small composite tubes and then back into Box C.

TRD Box S

TRD Box C

TRD Straw Tubes

TRD Gas Tanks

Xenon and CO2 is stored in two COPVs in Box S.

Both tanks were manufactured by Arde’ and are duplicates of previous designs.– Xenon tank was previously

used on ISS Plasma Contactor Unit (PCU)

– CO2 tank was previously used on X-33.

Warm Helium Gas Supply

Valves used on the flight cryosystem are gas-actuated.

Parallel pipework system used to deliver helium for valve operation.

Warm Helium Tank

Warm Helium Tank is a COPV manufactured by Arde’.

Tank is identical to previous design used on Pegasus vehicle.

Tank was designed for MDP of 5800 psi in Pegasus application, but AMS-02 will only pressurize to 2900 psi.

Thermal Control System

Thermal Control System uses heat pipes and loop heat pipes to transfer heat to the main and zenith radiators.– Main radiators use ammonia as working fluid.– Zenith radiators use propylene as working fluid.

All pipes operate in sealed mode and have no nominal or fault venting.

Most tubes are embedded inside radiators, but a few run along the USS, the Vacuum Case, or the Cryomagnet Avionics Box (CAB).

All tubes are manufactured by Iberespacio and are standard designs used throughout space industry.

Main Radiator Heat Pipe Layouts

Ram Radiator Wake Radiator

Zenith Radiator Loop Heat Pipes

Tracker Thermal Control System

Tracker Thermal Control System is a two-phase carbon dioxide system used to remove heat from the Silicon Tracker.

Tubes run along the sides of the tracker, across the Vacuum Case upper flange, to condensers on the Tracker Radiators.

Small heat pipe used in accumulator to optimize operations.

System operates in sealed mode and has no nominal or fault venting.

Composite Overwrapped Pressure Vessels

At Phase II Ground Safety Review, AMS-02 was asked to implement additional safety verifications based on draft COPV requirements.– Submitted Damage Control Plan for review.– All tanks reinspected by WSTF personnel.– Stress reports re-evaluated by ES4.– ES4 performed additional stress rupture calculations.

All AMS-02 COPVs passed inspection and stress report review did not identify additional issues.

All tanks and protective coverings are installed.Stress rupture reanalysis ongoing.

TRD Gas Supply Installed Configuration

Warm Helium Tank Installed Configuration

Conclusion

Details of each of these pressure systems are included in the Safety Data Package– TRD discussed in section 5.5.– Warm Helium Tank discussed in section 5.1.3.– Thermal Control System discussed in section 5.13.– Tracker Thermal Control System discussed in section

5.9.4.– Main pressure systems analysis included in Hazard

Reports #4 and #5. – Flammability issues reviewed in Hazard Report #10.