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Safety Summary of Significant Changes Since Phase II

Safety Summary of Significant Changes Since Phase II. This Presentation will:. Highlight changes to AMS-02 Highlight modifications made to Flight Hazard reports Will not detail verification status changes, those will be presented with hazard reports.

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Safety Summary of Significant Changes Since Phase II

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  1. Safety Summary ofSignificant Changes Since Phase II AMS-02 Phase III Safety Review

  2. This Presentation will: • Highlight changes to AMS-02 • Highlight modifications made to Flight Hazard reports • Will not detail verification status changes, those will be presented with hazard reports. • Updates to supporting data not reflected here. AMS-02 Phase III Safety Review

  3. ROEU Folding Bracket • As the ROEU extension outside of the ICD defined envelope for theAMS-02 CAS site is no longer deemed an impact to an adjacent ELC, the EVA operable PIP pins have been removed and replaced with fixed threaded fasteners. • Hazard Reports directly impacted • AMS-02-F11 • AMS-02-F14 • AMS-02-F18 AMS-02 Phase III Safety Review

  4. AMS-02 Magnetic Field Strength • The maximum current supplied by the AMS-02 Cryomagnet Avionics Box (CAB) to the superconducting magnet has been reduced by 7.6%. (459 A → 424 A) • New Value established through ground magnet quench “training.” • Associated with this change the ramp rate for charging and discharging the AMS-02 has been changed, to reduce the probability of a quench during discharge. • The number of dump diodes have been reduced to 9, to provide this reduced discharge rate. • Charging and discharging time has gone from 1.5 hours to 2.5 hours. AMS-02 Phase III Safety Review

  5. AMS-02 Cryosystem Modification • To protect the cryosystem during ground operations, a “burp valve” has been installed. • Allows for any long periods of quiescent operations (such as a hurricane rollback) for the AMS-02 to “burp” evolved gases if power is not available to operate the nominally operated vacuum pumps. • This protects from operating burst disks in the event there is a delay in restoring services while preventing air from being ingested into the Cryosystem. • Valve is isolated prior to launch. AMS-02 Phase III Safety Review

  6. AMS-02 TRD Gas Supply • The TRD Gas Supply has been modified to remove the Calibration Tubes (also referred to as Monitoring Tubes) that contain the radioactive Fe55 isotope. • The removal of the AMS-02 system’s only radioactive material removes the need for hazard report AMS-02-F09 • AMS-02-F05, Control 1.2 was revised to remove reference to the tubes containing the radioactive material. AMS-02 Phase III Safety Review

  7. AMS-02 TRD Gas Supply • The TRD Gas Supply has been modified to add a supply gas link so that alternative gas sources may be used while on the ground to keep the delicate tubes used in the sensing array from being reversed pressurized by atmospheric changes. • Supply only used on the ground. • Additional plumbing to the low pressure section of TRD that remains on the AMS-02 meets applicable flight requirements. • AMS-02-F05 tables updated for additional components. AMS-02 Phase III Safety Review

  8. AMS-02 TRD Gas Supply • The TRD Gas Supply Composite Overwrapped Pressure Vessels were provided with an additional MMOD shield on the inboard side. • Constructed of aluminum foam with aluminum skins. • Necessary to meet MMOD susceptibility requirements. • Provides additional protection of COPV to impact damage. AMS-02 Phase III Safety Review

  9. TRD COPV MMOD Shield MMOD Shield (Left) COPV Ground Shield (Below) AMS-02 Phase III Safety Review

  10. AMS-02 TRD Sensor • Low Pressure Gas supply manifold structure changed • Creates larger groups of “straws”, uses fewer and more simplified valve structure for controlling. • From 41 segments of straws to 10 • M-Structure of TRD equipped with redundant strings of 120 V resistive heaters (70 W) to minimize leakage past manifold flipper valve seats during cold soak. • Allows valve operations at cold attitudes. • Heaters not considered safety critical. • Each heater has two thermostatic control devices. AMS-02 Phase III Safety Review

  11. AMS-02 Warm Helium Gas Supply • The Warm Helium Gas Supply Composite Overwrapped Pressure Vessel MMOD shield design finalized. • Constructed of aluminum foam and aluminum skins. • Same Construction as new TRD Gas MMOD shield. • Check Valves added to relief valves to minimize helium loss past relief valve seats. • Raises relief pressure of the system by 0.35 bar • Hazard Report AMS-02-F03/ F05 reflects this change • Pilot Valves replaced with different valve as old valves consumed too much helium with each operation. • New valves do not suffer same reverse pressurization issue as old valves. • Hazard Report 5 updated to remove control for fracture criticality. AMS-02 Phase III Safety Review

  12. Warm Helium Supply MMOD Shield AMS-02 Phase III Safety Review

  13. Warm Helium Gas Supply • Check Valves added to relief valves to minimize helium loss past relief valve seats. • Raises relief pressure of the pressure relief valves by 0.35 bar (5.07 psi) • Hazard Report AMS-02-F03/ F05 reflects this change AMS-02 Phase III Safety Review

  14. Warm Helium Gas Supply Modification AMS-02 Phase III Safety Review

  15. Warm Helium Gas Supply • Pilot Valves replaced with different valve as old valves consumed too much helium with each operation. • New valves do not suffer same reverse pressurization issue as old valves. • Hazard Report 5 updated to remove control for fracture criticality of old valve bodies. • New valves require additional current to drive. • New electronics box created to take existing signals and provide appropriate control power to new valves. • Taps into UPS for additional power needs during ascent. • Compliant with active electronic design and thermal limits for ignition of flammable atmospheres. AMS-02 Phase III Safety Review

  16. Warm Helium Gas Supply • New Valves had different footprint than old valves • Redesigned PVVV built and installed. • Additional Plumbing was put in to augment the evacuation of the PVVV during ground operations. Additional Valve (DV09C) put in to control this connection. • Port and valve (MV80) was added so that ground operations could use alternate source of helium gas rather than flight pressure vessel. • Check valves added to feed line to warm pilot valves to limit helium consumption. AMS-02 Phase III Safety Review

  17. Warm Helium Gas Supply Modification New PVVV AMS-02 Phase III Safety Review

  18. Warm Helium Gas Supply Modification AMS-02 Phase III Safety Review

  19. Warm Helium Gas Supply Modification AMS-02 Phase III Safety Review

  20. Warm Helium Gas Supply Modification • New Valves require more power than old valves. • Required a new electronics box to “amplify” the power to the new pilot valves. • Cryomagnet Pilot Valve Switch (CPVS) Box. • Box powered by UPS during ascent. • Contains no Arcing/Sparking parts • Does not reach autoignition temperatures • Maintains UPS isolation from power distribution system • Small heaters added to pilot valve base plate. • Insufficient power to impact pressure in system • Thermostatic control implemented to limit application to cold attitudes. AMS-02 Phase III Safety Review

  21. AMS-02 UPS • The battery cells of the AMS-02 UPS have been replaced with new cells of the same design and pedigree as a subset of the previous cells were under-performing. • Energy content of the original UPS were still sufficient to fulfill mission objectives. • Concerns over life cycle trends dictated replacement of cells. AMS-02 Phase III Safety Review

  22. AMS-02 Radiators • Edges of the AMS-02 Radiator Panels, Main Ram and Wake and Zenith, were found to have inadequate rounding (full rounding required for thin sheets) of the aluminum surface sheets that faced the radiators. • Accessible edges were covered with a Teflon tape to preclude contact with the non-fully rounded edges. • Edges weren’t found to be sharp, only non-compliant with the NASA standard. AMS-02 Phase III Safety Review

  23. TTCS Line Heaters • Design of TTCS condenser line heaters finalized. Redundant heater “wire” wrapped around tubes as they go to radiators. • Additional Control added to AMS-02-F01 to relate potential thermal impact on adjacent composite struts. • Heater control structure consistent with heater philosophy maintaining two fault tolerant control to potential hazardous event (Excessive Heat). • Concern adjacent composite struts. AMS-02 Phase III Safety Review

  24. SSRMS Power • Maximum allowable current draw for SSRMS is16.7 Amps for payload power draw as a derated wiring specification. • In SSRMS warmest attitude and currents exceeding the specification, wiring may overheat insulation • AMS-02 has not pursued the fuse described as an option at Phase II from the design and instead took the path of confirming that maximum load (everything that defaults on) can not exceed SSRMS requirement. • All heaters on exceedingly unlikely as thermostatic control implemented on heaters. • AMS-02 would have to be in a significant cold position while SSRMS was in excessively hot position to reach AMS-02 maximum draw and approach SSRMS limit (16.2 to 16.7 Amps.) • AMS-02 active systems implement current protection AMS-02 Phase III Safety Review

  25. RICH Modification • RICH Aerogel volume was previously fitted with relief valves and bladders to minimize atmosphere intrusion during ground processing. • In order to make sure the aerogel remains dry, a low pressure (~1-2 psi) flow was provided for through this volume. • Uses the 1 psi relief vents, T fittings, and a ground source of dry nitrogen gas. • PTFE Piping and quick disconnects mounted to ease access to ports to connect gas supply. • At Phase II the volume of the aerogel and sodium flouride was not considered a pressurized system, and this modification did not change that categorization. AMS-02 Phase III Safety Review

  26. RICH Modification AMS-02 Phase III Safety Review

  27. TTCS • Tracker Thermal Control System • Differences in Primary and Secondary Loops were removed • Both looks now identical, “Experiment” valves in Primary Loop removed. AMS-02 Phase III Safety Review

  28. TTCS Location of Removed Valves AMS-02 Phase III Safety Review

  29. Warm Heliomatic Valve Modification • Warm Heliomatic Weka Valves were found to leak past the activation stem that attached to the bellows when transitioning between open and closed. • Leakage was small inclusion of atmosphere into the low pressure cryosystem lines • A low pressure manifold was put in place to place a helium blanket where it would be ingested in lieu of atmosphere. • Stainless Steel construction with 1/8” piping that can be evacuated or filled with a low pressure (1 bar or less) helium blanket. • Nine Weka Warm Valves modified. • Anomaly report AMS-02-A26 AMS-02 Phase III Safety Review

  30. Hazard Report Modifications • AMS-02-F01 – Structural Failure of Hardware • Add control for vented containers (ΦII Instruction) • Add new Cause and associated controls to address rotating equipment (ΦII Instruction) • Numerous small pumps exist in AMS-02 subsystems • AMS-02 On-Board Pump will operate on ground only (within payload bay), but flies with the AMS-02 into space. • Verification of Magnet Structure changed from 1.1x test to 2.0 analysis • Coordinated with SWG • Specific Verification on Acoustic Analysis/Test removed from verifications • Reference to JSC 23642E changed to JPR 8730.2 for fastener testing. • Under reconfiguration of AMS-02 (i.e. capture bar failed to be returned to nominal location) it was not desired by NASA to make this a planned or contingency EVA, Control adjusted to address method available, not specific EVA. • Folding ROEU Bracket removed from Controls (12.2) AMS-02 Phase III Safety Review

  31. Hazard Report Modifications • AMS-02-F02 – Toxic Material Offgassing • No modifications AMS-02 Phase III Safety Review

  32. Hazard Report Modifications • AMS-02-F03 – Rupture of Superfluid Helium Tank, Vacuum Case and/or Pressurized Systems • A modification to the “2 o-rings” on all non-welded Vacuum Case interfaces provides a caveat for specific electrical connectors a single o-ring is used with a Loctite 1C Hysol Epoxi-Patch potting used as a second sealing method. • Pressure Tables and Schematics updated AMS-02 Phase III Safety Review

  33. Hazard Report Modifications • AMS-02-F04 – Overpressurization of Orbiter Payload Bay • Control 6.1 modified to: • reflect that AMS-02 MLI will not be retained by what the project considers “soft” means of attaching MLI, including the use of hook and loop fasteners. • GFE which have been independently approved in their design and application of hook and loop fasteners to retain their unique MLI/blankets are being used within their certification. • Modification of controls to reflect that only a single burst disk now used on Vacuum Case emergency vent and two burst disks on the Super Fluid Helium Tank emergency vent • Control 5.2 updated with up to date quantity of propylene and specifies that it is in each of 8 tubes, previously the number of tubes was not mentioned in control. • Controls 5.3, 5.5 and 5.7 are updated with the final fill values of ammonia used in heat pipes and heat pipe loops. • All changes within the scope of previous analyses. • Schematic updates for TRD, Cryosystem and Warm Helium Gas Supply. AMS-02 Phase III Safety Review

  34. Hazard Report Modifications • AMS-02-F05 – Rupture of AMS-02 Pressure Systems: (list) • Control 1.2 modified to remove reference to TRD Monitor/Calibration Tubes. • Control 1.3 modified to reflect addition of check valves that minimize the leakage of gas past the relief valves. • This addition makes a minor alteration of the relief pressure of the system (.3 bar) • All components have adequate margin to account for this alteration. • Pilot Valves have been changed out for valves that do not consume as much helium in operation • New valves do not have reverse pressure criticality like previous valves. Control removed that was specific to old valves. • Control 8.6 revised to explain that Ram and Wake heater redundant heater strings only have two thermostatic controls per string as analysis shows that two strings must fail on to drive heat pipe pressure above MDP. Two fault tolerance to hazard does not required each string to be independently two fault tolerant. • Verification added to include Fault/thermal analysis. • Schematic and Table updates for TRD and Warm Helium Gas Supply. AMS-02 Phase III Safety Review

  35. Hazard Report Modifications • AMS-02-F06 – Excessive Thrust/ Overturning Moments • Control 2.2 was clarified to include not just cryogenic sources of potential thrust materials, but gaseous sources as well. • Correction made to Control 1.3 to reflect zero-thrust vents and not specifically “T” vents. • Schematic Updates for TRD and Cryosystem (including Warm Helium Gas Supply). AMS-02 Phase III Safety Review

  36. Hazard Report Modifications • AMS-02-F07 – Excessive Field Strengths: EMI, Magnetic (DC Field) • Magnetic field nominally 7930 Gauss included in controls. • Maximum Cryomagnet Current now 424 not 459 and changes made accordingly in Control 1.8 • Typographical error in SVM 1.3.4 • Control 1.4 and 3.1 removed erroneous statement about switching of cables by EVA during a launch phase. • Verifications modified to account for this as well • Verifications for 1.5 and 3.2 modified to account for Go-No Go call not being an LCC and being an OMRSD • Redundant and poorly worded duplicate verification removed from control • Control 1.6 specifically describes that Hall Effect sensors will detect magnetic field’s presence. • Safety Verification 1.6.9 added to establish EVA keep out zones for excessive magnetic fields as OCAD submittal. • Added Control 1.10 addressing magnetic field impact on visiting vehicles (none) per Phase II Agreement. AMS-02 Phase III Safety Review

  37. Hazard Report Modifications • AMS-02-F08 – Electric Shock/ Discharge • No Modifications AMS-02 Phase III Safety Review

  38. Hazard Report Modifications • AMS-02-F09 – Exposure of the Crew to Excessive Ionizing Radiation • The source of radioactive Fe55 has been removed from the payload • Hazard Report Withdrawn for Phase III AMS-02 Phase III Safety Review

  39. Hazard Report Modifications • AMS-02-F10 – Flammable Materials in the Payload Bay • Added Cause 3 and Control 3.1 for ignition of non-AMS-02 Source flammable materials • Control of potential hotspots, electrical sparking equipment, etc controlled as per letter NS2/81-MO82 and MLI grounded per ICD 2-19001. • Added verifications for: • Thermal Analysis • Review of Design • Grounding Testing of MLI • All values for Ammonia and Propylene fill quantities changed to final as measured values. AMS-02 Phase III Safety Review

  40. Hazard Report Modifications • AMS-02-F11 – Mechanism Failure • Verification 5.1.4 erroneously referenced travel limiters which have no impact on control, changed to relevant component, Load Release Screw Locking Mechanism. • Control 6.1 modified to account for ROEU folding bracket no longer folding. • Verification 6.1.1 deleted • Control 6.2 deleted in entirety to account for the ROEU folding bracket no longer folding. • Four verifications deleted. AMS-02 Phase III Safety Review

  41. Hazard Report Modifications • AMS-02-F12 – Mate/Demate of Connectors • Control 1.6 added to account for the need to deadface T-0 power prior to launch. • Verifications confirm ground procedures and required additional LCC for AMS-02 sourced power. • Modification required by KSC operations to protect the flight vehicle. • Control 1.4 was giving a Review of Design verification (1.4.1) and the Testing Verification became 1.4.2 and the list of EVA accessible connectors was modified to PVGF and ROEU as well. AMS-02 Phase III Safety Review

  42. Hazard Report Modifications • AMS-02-F13 – Battery Failure • Descriptive bullet list attached to hazard report updated to reflect the SDP text and control 3.2 on stack level monitoring for overdischarge. AMS-02 Phase III Safety Review

  43. Hazard Report Modifications • AMS-02-F14 – EVA Operational Hazard • Control 1.1 modified to clarify that FRGF and PVGF EVA Release have been approved for both free float and use of the WIF socket. • Control 1.2 modified to remove “with a 7/16 inch drive” • “Drive” is the interface between the “socket” and the “tool” not the “socket” and the bolt. Prepositional phrase added nothing to the control and was deleted. • Verification 1.3.3 went from “Crew EVA inspection” to “Crew inspection” as the inspection was to be on flight hardware at KSC, not during an EVA. • Control 4.1 was modified to account for AMS-02 NCR-001 for EVA Touch Temperature violations. • Verification 4.1.2 added for approval of the NCR.. • Control 4.2 was modified to clarify that the touch temperature compliance was limited to areas that were accessible to an EVA crew member. • Control 4.2.3 modified to account for the functional testing of the heater circuitry including the heaters and thermal switches, not just the thermal switches. • Control 5.3 and associated verification deleted as ROEU folding bracket no longer folds. • Control 6.1 removes reference to folding ROEU bracket from list of EVA tasks. • Control 10.2 modified to reflect that the ROEU folding bracket no longer folds, retaining the verifications that the protrusion is documented and not extending to the adjacent payload’s envelope. AMS-02 Phase III Safety Review

  44. Hazard Report Modifications • AMS-02-F15 – Thermal Extremes • Still Deleted from Phase II AMS-02 Phase III Safety Review

  45. Hazard Report Modifications • AMS-02-F16 – Shatterable Material Release • Control 1.5 and 1.7 modified to reflect that vents of laser source boxes are unfiltered 50 micron holes and that now interior components are contained within housings or fibers within jackets. AMS-02 Phase III Safety Review

  46. Hazard Report Modifications • AMS-02-F17 – Electrical Power Distribution Damage • Control 1.2 modified to reflect new consensus on SSRMS Power utilization that allows for the removal of the AMS-02 supplied fuse. • Control 1.3 removes reference to Cryomagnet Avionics Box from control as it is not relevant to the control. • Control 2.4 referenced incorrect control in hazard report AMS-02-F12. AMS-02 Phase III Safety Review

  47. Hazard Report Modifications • AMS-02-F18 – Rapid Safing/Payload Reconfiguration • Control 1.6 added to address the rapid safing analysis to show that Orbiter can be safed during AMS-02 transfer within1 hour and 35 minutes. • Safety Verification 2.2.2, inspection of hardware, not applicable to control and deleted. • Control 3.3 was rewritten as a repair solution and not an established EVA as it required multiple failures and operational errors to get to that point and it wasn’t considered contingency or nominal EVA. • Control 3.4 deleted as ROEU folding bracket no longer folds. AMS-02 Phase III Safety Review

  48. Hazard Report Modifications • AMS-02-F19 – Excessive Glare • Withdrawn prior to Phase II safety review, PSRP concurred with this action at Phase II. AMS-02 Phase III Safety Review

  49. Hazard Report Modifications • AMS-02-F20 – Crew Exposure to Coherent Light • No Modifications AMS-02 Phase III Safety Review

  50. Hazard Report Modifications • STD-AMS-02-F01 – JSC Form 1230 for AMS-02 Exterior Elements • Per Phase II instructions, the content of this hazard report have been reassigned to other hazard report. • Sub HR 3 moved to AMS-02-F01 • Sub HR 12 moved to AMS-02-F10 • Sub HR 13 moved to AMS-02-F01 AMS-02 Phase III Safety Review

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