XA/EVA Project Office Weekly Activity Report September 6, 2001
EVA Maintenance Technical Interchange Meeting
The EVA Project Office conducted an EVA Maintenance TIM on August 28 and 31, 2001, with support from Mission Operations Directorate, International Space Station Program and Flight Crew Operations Directorate, Engineering Directorate, and Boeing EVA. The majority of the TIM involved overview type presentations in order to establish a base level of understanding for future work. In addition to many minor issues raised, the major issue which will be worked by Mission Operations as a result of this TIM is to determine the time-criticality of changing out the system critical ORU’s, to determine if the current methods of training and pre-flight planning are adequate to perform the EVA to changeout those ORU’s in the time required, or if changes in the maintenance preparedness philosophy are warranted. A core group of individuals will meet periodically to work off the other issues raised and to flush out other potential problems.
EMU Executive Program Review.
On August 30, 2001, NASA, Hamilton Sundstrand and USA participated in the EMU Executive Program Review co-chaired by the EVA Project Manager, Allen Flynt and the Hamilton Sundstrand General Manager, Larry McNamara. The full day review concentrated on the technical, cost, and schedule risks associated with sustaining of the EMU program and development of EMU upgrades. Areas emphasized and discussed in detail were the recovery plans for the following: refurbishment of 3 of the 14 primary life support systems, production of the primary oxygen pressure regulator, production and procedural control of advanced batteries, and boot fit issues. In addition, the contractor provided insight into the status of the development of the small suit, the modified drink bag, oxygen pressure transducer, and caution and warning system programs. In summary, this review was comprehensive and continues to be both beneficial for NASA and the contractor in evaluating and prioritizing program risks.
Test Readiness Review (TRR) for Module to Truss Structure (MTS) Strut Deployment Test
A TRR for the MTS strut deployment test was completed. During the TRR high loads were experienced during extension of the qual bipod strut groups. The high forces may be due to 1G effects or hardware design issues. After extensive review the test team has concluded that it is not practical to eliminate 1 G effects from the strut deployment test. A KC-135 Zero G aircraft test is planned for early November to determine whether the high forces are due to 1 G effects or hardware issues. The test team agreed it is beneficial to continue plans for a 1 G test of both flight bipods and one qual tripod group. This test will show the strut deployment, strut extension, tool stack up, and gloved hand clearance. The KC-135 evaluation will only test the extensions of one bipod qual group.
Corrosion in Top Mounted Handrail Brackets
The problem of the corroding handrail brackets was determined not to be specific to one build set during inspections performed at KSC. Also, during this investigation, it was discovered that the depth of the step within the through hole of the bracket varied greatly between build sets. As a result, the EVA Project Office organized a test with the support of the Engineering Directorate’s, Mechanical Design and Analysis Branch, to verify that these discrepancies within the handrail bracket did not compromise the structural integrity of the handrail. On August 31, 2001, a destructive load test was performed and the handrail brackets with the worst corrosion failed at a slightly lower load than non-corroded brackets. This lower load was still well with the safety margin. Therefore, all handrail brackets, including on-orbit handrails, are capable to withstand the certified loads. The EVA Project Office will approve interim FIAR closures in order to exonerate all handrail brackets.
Original signed by:
Stephen C. Doering
Deputy Manager, EVA Project Office
