From: Johnson Space Center
Posted: Thursday, July 13, 2000
EMU O2 Contamination Recovery Status
Since hydrocarbon contamination on a Secondary Oxygen Package (SOP) regulator was first reported on 6/14/00, the EMU and JSC engineering community have steadfastly embarked on four main branches of recovery efforts. First, a plan for disassembling, cleaning, and rebuilding all SOP systems was put into place. This plan provides for three SOPs to support the current STS-106 launch date. Currently, Hamilton Sundstrand and Carleton Technology, the regulator vendor, are on schedule with this effort. Second, the JSC engineering community has recommended operation of the PLSS system as is, based on WSTF testing and analysis. In addition, samples taken from flight regulators to date suggest negligible contaminants exist in the primary system. Third, clearing use of test stands at USA and Hamilton Sundstrand is in work. Development and testing of cold traps (filters) should be completed this week, allowing USA to begin processing Short EMUs for the upcoming flight next week. Finally, JSC Safety is working hand-in-hand with these efforts to understand and relay the risks to other NASA flight and ground systems.
EMU Mishap Investigation Status
The EMU mishap investigation report was completed and signed by the board members on June 29, 2000. The debrief to the Engineering Directorate and the EVA Project Office management occurred on July 11, 2000, and the presentation to the Director JSC is scheduled on July 21, 2000. Findings, observations , conclusions and recommendations will be addressed in the presentation.
Service Module (SM)
Service Module was launched successfully at 11:56 p.m. July 11. Deployment of Kurs, Lira and solar arrays appears to be successful. Moscow did not receive positive telemetry indicating the nadir docking target has deployed but indicated that the pyro had successfully fired. Activation of onboard thrusters and scheduled attitude adjustment may nudge the target into itís final position. The docking target supports SM/FGB contingency 1R.1 assisted berthing using manual TORU in the event the Kurs antenna fails. We are following events to determine if deployment will need to be addressed on 2A.2b. The docking target is not used again after FGB/SM berthing, but covers plate 7 connectors required for 2A.2b and Docking Compartment-1. SM/FGB Docking is targeted for July 25 at 7:10 p.m. Progress 251 launch is shown as July 31 with docking shown August 2.
Cupola TIM and Joint Program Review
The EVA Project Office supported the Cupola TIM the week of June 26, 2000. The meetings ended with a NASA/ESA Joint Program Review (JPR). The two EVA items discussed were the requirement to provide EVA hardware interfaces to support two EVA crewmembers during a task and the inability of the Cupola shutters to meet loads requirements for both EVA and on-orbit ISS loads. Both NASA and ESA program managers agreed to changes to the Cupola requirements that would support two-EVA crewmember tasks for both contingency and maintenance tasks such as window changeout. This requires additional EVA worksite interfaces and handrails on Node2 to support a crewmember on a foot restraint. The second crewmember will be on the robotic arm. A change request was signed by NASA managers that updates the Cupola requirements document and directs MSFC to analyze the feasibility of adding the new EVA hardware to Node3.
ESA analysis showed the seven Cupola shutters cannot meet the 2.0 factor of safety margins when the shutter is fully opened for both EVA kick loads of 125 lbf or on-orbit loads. EVA agreed it is acceptable to close adjacent shutters during an EVA, but, could not completely insure a crewmember would not kick the open shutter on the window where the task is performed. As a relief to the loads requirement, Boeing and NASA structures experts determined the loads factor of safety can be reduced from 2.0 to less than 1.5 in some cases due to the specific locations the Cupola resides on ISS. ESA agreed to rerun loads analysis with the reduced safety margins to determine if they come close to or meet the new loads requirements with the current hardware design. The EVA AIT will review the loads issue next week to determine if the factor of safety reductions are acceptable for EVA kickloads. Both programs will convene in September 2000 once ESA completes the loads analysis.
EVA ORU Labels for P6 Approved
The ISS Program approved directive 3568 sponsored by the EVA Project Office. This directive provides for installation of new EVA compatible ORU labels on 17 ORUís on the P6 truss element. The labels have been produced and shipped to KSC. The labels are scheduled to be installed this week. After installation of these labels, all of the ORUís on P6 will have EVA compatible labels.
Gregory J. Harbaugh
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