XA/EVA Project Office Weekly Activity Report April 26, 2001
STS-100/6A EVA’s
Both EVA’s planned for STS-100/6A were successfully completed. Tasks included deploying the SSRMS, installing the UHF Antenna, removing the starboard ECOMM antenna and transferring the DCSU to ISS. One task which was not completed was removing the Video Signal Converter (VSC) from the Space Lab Pallet (SLP). The VSC bolt was not able to be released from the SLP, so it will be returned in the PLB. The task was supposed to bring the VSC inside ISS for on-orbit stowage as a spare, to be installed during the UF-2.
Some anomalies were encountered when powering up the SSRMS. The 6A team had to remate a connector installed on the Power Data Grapple Fixture to allow for redundant power to be fed to the SSRMS. Also, disconnecting the Starboard ECOMM antenna and several cables, one of the two electrical connectors being demated came apart. The EVA crew noted a wing nut and two screws were missing from the one connector and one screw was missing from another connector. The debris is believed to be contained within the CBM MLI cover on the NODE Starboard hatch. Several visual inspections were completed EVA, but no debris was found. Plans are under development to address this concern for STS-104/7A.
EMU Minimum Plasma Arc Voltage Test
EVA Project Office personnel presented the plan for the EMU Minimum Plasma Arc Voltage Test to the ISS Vehicle Control Board, with the support of Hamilton Sunstrand (HS) personnel in Connecticut. The plan delineates the tasks necessary to establish the minimum voltage at which arcing would occur with the EMU in the ISS plasma environment. Once this minimum voltage is established, the EVA Project Office can effectively assess the hazard to the crewmember in the EMU with respect to the expected ISS electrical potential level during EVA. The testing is expected to provide statistical data to sufficiently support an integrated analysis of the arc voltage for the EMU. The chairman concurred with the test plan and authorized funding to MSFC for the test facility support. The testing is scheduled to begin within the next two weeks, pending the completion of the test setup and finalization of the test procedures by the HS and MSFC test team.
ISS-3 Training
The ISS-3 prime and backup crew conducted US maintenance EVA NBL training April 19 and 20. Maintenance tasks planned for the NBL included utilization of the Early Ammonia Servicer (EAS) to refill the P6 Thermal Control System and Sband Antenna removal and replacement. EAS training went as planned, though lack of finalized procedures resulted in some variances. 7A.1 is in the process of developing these procedures for the 105 EVA checklist. Sband antenna removal and replacement could not be performed due to interference of an Airlock High Pressure Gas Tank (HPGT) with the Space Station remote Manipulator System (SSRMS). The team is investigating workarounds for this problem. A maintenance proficiency run and 7A.1 cleanup run remain for the prime ISS-3 crew, and two remaining maintenance runs are also planned for ISS-3 backup crew (ISS-5).
Original signed by:
Stephen C. Doering
Acting Deputy Manager
G. Allen Flynt
Acting Manager
