XA/EVA Project Office Weekly Activity Report August 30, 2001
P4/S4, P5/S5 Functional Configuration Audit (FCA)
EVA Project Office personnel supported the ISS Elements P4/S4, P5/S5 FCA and coordinated with Boeing EVA representatives to close as many open issues and actions as possible for these elements. Minimal open work remains in the EVA area. Actions required for closure have been identified and scheduled for implementation. The FCA team was satisfied with the closure progress of the EVA requirements and open work remaining.
Electronic Control Unit (ECU)/ Beta Motor Roll Ring Module (BMRRM) EVA Direction
The August 21, 2001, SSPCB reviewed the issue of replacing BMRRM during a UF-1 based EVA. Also addressed was the question of when to perform a potential ECU changeout. The decision was made to continue to prepare the UF-1 crew for BMRRM changeout, pursue potential workarounds with the Z Perpendicular to the Orbital Plane (ZPOP) attitude and continue to gather information on the failure mode. It is still not clear if the fault lies within the BMRRM or the ECU. Given this lack of hard evidence, the SSPCB declined to request that the EVA Project Office pursue replacement of the ECU in September 2001, during the ISS-3 increment. A decision will be made by the end of September regarding whether to pursue replacement of the ECU in the November timeframe, which is the only other window for the EVA due to DC-1 launch and activation EVA’s. The ISS-3 ECU EVA sub-team wrapped up work in progress to await further program direction. The August 30, 2001, end-to-end ECU NBL run will proceed in order to finalize the ECU changeout procedure
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Corrosion in Top Mounted Handrail Brackets
The EVA Project Office conducted additional inspections of handrails at KSC last week with support from the Engineering Directorate and SR&QA. These additional inspections were performed in order to determine if the problem of corrosion in the handrail brackets was specific only to one build set. Initial inspections of all the handrail brackets at JSC supported the theory that the corrosion was present in only one build set. However, during the inspections at KSC, corrosion was found in handrail brackets from other build sets. As a result, the EVA Project Office is organizing testing and analysis in order to exonerate all handrails that are assembled with this particular handrail bracket, which includes Gold Anodized Top Mounted Handrails, Clear Anodized Top Mounted Handrail, and Custom Handrails. Also, a safety alert, JSC NASA Advisory, TWX-A-01-12, has been issued requesting that all installations involving the aforementioned handrails cease until the testing can be completed.
EMU Boot Fit
The EVA Project Office is nearing completion with the investigation into the boot fit concerns from recent flights. The root cause for this condition centers on appropriate sizing pre-flight and assembly of the boot itself. From this point forward crew fit checks for boots will be performed with a new operation that involves suspending the crewmember to simulate 0-g conditions. In addition the TMG lacing on the boots will be loosened to alleviate the binding occurring around the top of the foot. No design changes are required to support this issue closure. The EVA Project Office is now working with the Engineering Directorate and prime contractor to formally invoke the procedural changes.
S0/S1 On-orbit Constraints Testing
The EVA community supported S0/S1 On-orbit Constraints Testing August 21-23, 2001, at KSC. All cables and fluid jumpers mated successfully. The test showed that the avionics harnesses must be mated in an unplanned but acceptable sequence, the fluid QD lever tool can only be used on the inboard side QD#2 at panel A502, and the cable #W4102/P13 must be routed outboard of the capture latch override bar. In addition, three cables were deemed adequate for operations, but did not meet minimum pretest requirements for line length (W4008/P12, W4147/P5, W4213/P6). Discrepancy reports were taken for Boeing evaluation. Overall, the test provided verification of on-orbit line reach and provided useful operational information that will help ensure successful on-orbit mating for S0/S1 cable and fluid interfaces.
STS-109 Hubble Space Telescope (HST) Servicing Mission 3B (SM3B) EVA CCB Mid Flow Review and EVA Assessment Team (EVAAT) Recommendations
The EVA CCB conducted a mid flow review of STS-109, HST SM3B. The CCB reviewed the current status of the preparations for the mission including EVA hardware manifest and development, fit checks, EVA timelines, training, procedures and flight rules. The EVAAT also presented recommendations to the CCB from their evaluation of STS-109 NBL training. Overall, the mission is in good shape. There are plans in place to resolve all of the open issues prior to the flight. EVA 3 (Power Control Unit replacement) is predicted to exceed the 6 hour 30 minute EVA planning guideline by 30 minutes. The CCB and EVAAT concluded that the EVA is appropriately planned and that an exception to the planning guideline was justified. The remaining EVA’s are expected to be achieved within the 6 hour 30 minute guideline.
Original signed by:
Michael J. Mankin
for
G. Allen Flynt
Manager, EVA Project Office
