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X-Ray Gratings Mission. Integration & Test Harvey Safren 19 – 23 March 2012. From NASA Procedural Requirements, NPR 8705.4, Appendix B. Class B Missions Single Point Failures (SPFs)
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X-Ray Gratings Mission Integration & Test Harvey Safren 19 – 23 March 2012
From NASA Procedural Requirements, NPR 8705.4, Appendix B Class B Missions Single Point Failures (SPFs) Critical SPFs (for Level 1 requirements) may be permitted but are minimized and mitigated by use of high reliability parts and additional testing. Essential spacecraft functions and key instruments are typically fully redundant. Other hardware has partial redundancy and/or provisions for graceful degradation. Engineering Model, Prototype, Flight, and Spare Hardware Engineering model hardware for new or significantly modified designs. Protoflight hardware (in lieu of separate prototype and flight models) except where extensive qualification testing is anticipated. Spare (or refurbishableprototype) hardware as needed to avoid major program impact. Qualification, Acceptance, and Protoflight Test Program Formal qualification and acceptance test programs and integrated end-to-end testing at all hardware levels. May use a combination of qualification and protoflight hardware. Qualified software simulators used to verify software and system.
I&T Assumptions • Existing Goddard facilities are sufficient for observatory environmental test, but maybe not for optical testing; GSFC is baselined for observatory I&T, and both GSFC and MSFC XRCFwill be considered for optical testing. • Payload and bus delivered to GSFC ready for observatory level I&T • Fully qualified per GEVS • No additional stand-alone testing required • Subsystems include: • Power: solar arrays, battery (nonflight thru observatory testing) • Thermal: cryocooler, radiators • ACS: Star tracker, CSS's, reaction wheels, gyro, thrusters • Comm: Ka-band antenna, S-band HGA & omni • Task durations: • Include transfer and prep/setup overhead • Are "success-oriented" and do not include margin/reserve • Test-specific assumptions: • Dry vibe (wet vibe could be considered) • Wet thermal-vac • Thermal-vac includes radiators but not solar array • No jitter test or spin balance required • Some unique GSE required: • Electrical: ground test system, flatsat, spacecraft simulators • Mechanical: deployment test fixtures (g-negation), dollies, slings • Thermal: Cryo / heater panels, TCUs • Fluids: prop servicing, GN2 purge • Test conductors from Flight Ops Team; ¾-time for I&T support • Those who will be operating spacecraft during mission train during I&T
Special GSE Required for I&T effort • X-ray point source GSE used to monitor contamination in optical path, especially FMA. Gives realistic measurement of science degradation, indicate contamination event • Electrical & Mechanical simulators: • S/C simulator for testing with the payload • Payload simulator for testing with the S/C Bus • FMA mass simulator for testing with the S/C Bus • S/C Bus & Instrument Deck ETU for cold deployment testing
I&T Grassroots Cost Estimate Note: This estimate does not include GSE, simulators, shipping containers, etc.
Top-Level I&T Flow Chart Structures assembly & test & propulsion system integration Electrical harness integration Power System and battery integration C&DH, avionics & FSW Integration & func. test GN&C system I&T Comm. system integration Thermal systems integration Integration of lower part of metering structure FMA mass simulator installed Vibration testing Solar array integration Thermal testing Functional & LPT testing with FSW & GSE; Remove mass sim. To observatory I&T Bus I&T – 7 “months” (1 “month” = 28 days) Integration of upper part of metering structure Ambient functional testing &Mission simulations Integration of FPA & FMA Thermal blankets, coatings, heaters, thermistors Alignment baseline PER To environmental test at MSFC Pre-environmental CPT at ambient Vibration testing in launch config. Acoustics testing in In launch config. End-to-end RF testing EMI/EMC Separation/ Shock test Ejection mechanism testing Therm/vac (4 cycles) & thermal balance Post-environmental CPT at ambient & alignment check Mass properties measurements PSR To launch site Observatory I&T – baselined at GSFC – 9.5 “months” (1 “month” = 28 days)
Top Level Flow for Launch Site Operations Post-ship functional tests, deployment tests & alignment checks Flight battery integration & conditioning Move to hazardous facility & load propellants* Receiving & Inspection Integrate & check remaining external items Aliveness test Hoist & mate to launch vehicle Encapsulate in fairing Transport to launch pad Pad aliveness test Post-launch I&T operations LAUNCH Pad closeouts (tags, plugs, etc.) Launch dress rehearsal Flight Readiness Review (FRR)
Issues/Concerns/Considerations Test Facilities • GSFC test facilities are sufficient for X-ray Gratings observatory, but some comments: • New vibe cell planned for JWST in Bldg 29 high bay should accommodate X-ray gratings observatory; • The GSFC shaker is currently out of commission; it is not known when it will be restored; • GSFC SES 40 ft height may be sufficient for observatory optical test (~27 ft observatory height gives X-ray point source GSE ~13 ft height allowance); • Making overall test fit SES would provide significant program cost savings; • A list of sufficiently large alternative thermal/vac chambers is given in the next slide. • MSFC XRCF identified as baseline optical / thermal test facility, but MSFC environmental test facilities may not accommodate the observatory. • Should look into Wyle Laboratory capabilities local to MSFC. • Alternative: ship back to GSFC for environmental test; GSFC is currently baselined for observatory I&T.
Alternative TVAC facilities • There are five thermal vacuum chambers in the US that are large enough to accommodate the observatory (which is approximately 27 ft tall) in a vertical orientation, located above a GSE point scanning X-ray source • Arnold Engineering Development Center, Arnold AFB, Tullahoma, Tennessee; 42’ diameter by 82’ high (vertical) • NASA JPL, Pasadena, California; 27’ diameter by 85’ high (vertical) • NASA JSC, Houston, Texas; 65’ diameter by 120’ high (vertical) • NASA GRC, Plum Brook Station, Sandusky, Ohio; 100’ diameter by 122’ high (vertical) • Lockheed Martin Missiles and Space, Sunnyvale, California;40’ diameter by 80’ long (horizontal) Pressure 10-6 10,000 clean room Wet/dry mass ~3000 kg
CAT Configuration • No appreciable impact on I&T is seen from using the CAT configuration.
I&T Objectives • Maintain a Safe Environment For I&T Personnel and Flight H/W • Maintain the Cleanliness Conditions for the AXSIO S/C & Instruments • Verify all Flight Mechanical and Electrical Interfaces • Develop and Verify Command and Telemetry Database, • All Commands and Telemetry Must be Exercised at Least Once • Perform Environmental Qualification of the AXSIO Observatory • Verify Observatory Performance Requirements are Met Throughout the Environmental Test Program, Including (to the extent possible) Instrument Performance in Thermal Vacuum • Verify Observatory Compatibility with AXSIO Mission Operations Systems • Make AXSIO Ready For Launch, assist in integration to launch vehicle.
I&T Program elements • I&T Flow • I&T Schedule • List of GSEs, Simulators, Test Languages, Main Procedures • Facilities, Floor Plan layouts, IT Networking • Manpower • Cost • Verification Matrices • Verification Method: T/A/I/D • Verification Level: F/PF/Q • Verification Unit: F/PF/ETU, etc. • Verification Philosophy • Test As You Fly ! • Verify each requirement at the highest level possible • Operation of an element is verified after integration into a higher level • Performance Verification and Environmental/Workmanship Verification • Models Philosophy • ETU’s, Breadboards, Brass boards, etc. • Heavy testing / qualification on Test Models, Brass boards, EM, Acceptance testing on Flight Models
Verification Program Overview • Establish confidence that the Mission will be a success • Verify: • Functional, Performance, and Operational Requirements • Requirements • Mission Level Functional, Performance, Interface, and Operational Requirements • Workmanship Standards • Materials Control • Quality Assurance
I&T Assumptions - Requirements1 of 4 • Flight hardware will be qualified per GSFC-STD-7000, the “General Environmental Verification Standard” (a.k.a. GEVS) dated April 2005. • All lower assembly level hardware structures, boxes & components through Module level will be fully qualified per GEVS at their level of assembly prior to delivery to observatory I&T, given any additions/exceptions. • The Goddard Open Learning Design (G.O.L.D.) Rules for the Design, Development, Verification, and Operation of Flight Systems (GSFC-STD-1000 Rev D, June 2008) will be applied.
I&T Assumptions - Process2 of 4 • Although it may occur elsewhere, the process of observatory flight hardware Integration is baselined at NASA GSFC, in Greenbelt, led by GSFC personnel, and conducted per GSFC directive 568-PG-8700.1.1B. • Structural verification model built and used for structural test to verify structure models, alignment process development, and deployment testing, w/o risking damage and contamination of flight structure. • Observatory environmental testing performed with no mass simulators, mockups, protoflight units etc. • Enables Test as you fly, demonstrates self compatibility
I&T Assumptions - Cost3 of 4 • Matrixing of I&T labor is successful, especially during Phase A through Phase C where the discipline teams are building up with respect to FTEs. • Most of the observatory I&T costs are for labor. The remaining observatory I&T costs are for other (e,g., facilities, GSE, materials, TDY, training, infrastructure, packaging, shipping). • Except for selected tests, all schedule and flow elements are based on labor rates of an 8-hour per day shift, 5-day work week and observance of Federal holidays • The deliverables to observatory I&T are complete staggered, and on time • In practice, at least 20% contingency is included in planning to “merge” I&T planning estimates with past project history to allow for retesting of failed components, delivery delays, unexpected shift work and other unplanned costs as are inherent in the implementation phase of the I&T process.
I&T Assumptions – Facilities & GSE4 of 4 • GSFC or other integration and test facilities are ready and available when needed • Identification of all Module- and Observatory-level test facilities and support off-site is complete and accurate. • Rigorous contamination control including special filtration, constant N2 mirror purge, continuous real time monitoring, scheduled cleanings and black light inspections. • Preserves science integrity. Must be considered in selection, configuration and operation of facilities, cost driver, schedule driver. • All GSE and materials slated for use at the observatory I&T site are identified. • All GSE slated for use at the launch site will be CCAFS-certified in advance, calibrated, and at hand
GSE Required for I&T effort1 of 3 • NOTE: Substantial amounts of GSE are required to support the integration effort. Much of this equipment will be developed and used at the subsystem level and be delivered with the flight hardware to I&T. Other equipment will be developed specifically for I&T use. • Only GSE identified in the following table as being provided by I&T is included in the I&T costs. The costs for all other GSE are assumed to be carried by the group identified in the column marked “Provider.” • The costs and development schedule of this equipment is not trivial. This list is not meant to be exhaustive or complete.
