XA/EVA Project Office Weekly Activity Report September 21, 2000
PCU issue
The EVA Project Office continues to support the effort to evaluate the operational scenarios associated with post 4A EVA sorties should the ISS Plasma Contractor Units (PCU’s) experience a failure. ISS controls of the failed PCU issue were presented to the ISS Program and a plan to provide dual fault tolerance is in work. All of these controls assume that the EMU-produced environment (water vapor and oxygen leakage) will not extinguish the PCU’s themselves. This issue is scheduled for resolution this week. In addition to these ISS hazard controls the EVA Project Office is evaluating improvements to the EVA systems as an additional hazard control.
Orlan Technical Review
The Russian EVA Technical Review was held on September 15, 2000 and was chaired by the Manager, EVA Project Office. Russian task status was presented including the Orlan Safer, Russian EVA assurance, GCTC sustaining engineering and operations, and Orlan expertise. A preview of the CoFR 2 charts for 2R (ISS-1) was presented for Russian EVA hardware. Orlan consumables and logistics were presented, and an action was taken to address consumables shortages below the plus-two contingency during increments two and three. The Orlan mission support plan was also discussed by MOD and CTSD for Orlan based EVA’s. Crew requested hardware for ISS 1, EC Orlan suit status, Orlan safety and results of the August Zvezda TIM were also discussed.
Simplified Aid for EVA Rescue (SAFER)
During calibration of the pressure transducer on S/N 1006 SAFER, which was being processed for STS-92, two cables were accidentally swapped. The hand controller cable was connected to the rate sensor connector on the avionics box, and the rate sensor cable was connected to the hand controller connector. When power was activated, anomalous conditions were observed on the hand controller display. Upon additional checks, the hand controller board and rate sensors were found to be damaged, and the avionics control board was suspected to have overstressed electronic parts. One of the STS-106 units will be turned around for STS-92 as a substitute for this unit. The Engineering Directorate has instituted a corrective action team to prevent similar problems in the future.
EMU O2 Contamination Recovery Status – Update 9/20
With the successful completion of the STS-106 mission, the three Secondary Oxygen Packages (SOP’s) currently on the Orbiter will be expedited back to Houston within 48 hours of landing for nominal flight processing. The current plan is to integrate two of these three SOP’s with two of the EMU’s slated for STS-92. The third SOP assembly slated for the STS-92 mission was shipped by Hamilton Sundstrand on 9/15/00 and was immediately integrated with an EMU here at JSC to complete two vacuum chamber runs required for acceptance testing of hardware for the next flight. To date, four (4) SOP assemblies are ready to support flight. A fifth SOP is anticipated to be ready by 9/30/00. By mid-January next year the EMU program should be able to maintain a minimum of twelve (12) refurbished SOP’s in inventory.
SEMU 1018 Hardware Status
Inspection and testing has been completed for several of the EMU components involved in the dropped Short EMU incident. Specifically the Hard Upper Torso, several electrical harnesses, and pressure sensors have been evaluated and deemed flightworthy. Major items like the display and control module, sublimator and fan/pump/separator appear to be okay, but further thermal and vibration testing is required to completely ensure these items are ready for flight. The estimated completion date for all assessments of all the components involved in the incident is November 30, 2000. The current conservative estimate for return to flight for Short EMU 1018 is July, 2001.
Original signed by G. A. Flynt for
Gregory J. Harbaugh
Manager
