Status Report

XA/EVA Project Office Weekly Activity Report May 31, 2001

By SpaceRef Editor
May 31, 2001
Filed under , ,

STS-104/7A EVA Flight Readiness

EVA Project Office reports that all STS-104/7A EVA flight issues have been closed and the remaining work (final sharp edge inspections, EMU installation and checkout) are standard for being open at FRR. Several special topics will be discussed at FRR per JSC management request, including Exercise Prebreathe Protocol readiness, Stage 6A EVA Status and readiness, and a new technique for use of the Bends Treatment Adapter.

Bearing Motor Roll Ring Module (BMRRM) Anomaly Resolution Team (ART) Status

EVA Project Office representatives continue to work with the BMRRM ART to address the anomalous BMRRM operation on-orbit. The EVA community is developing EVA remove and replace (R&R) procedures for the BMRRM. At the SSPCB on May 29, 2001, the decision was made to not perform a BMRRM R&R on flight 7A.1 to allow the BMRRM ART more time to determine the root cause of the problem. Should a decision be made at a later point that a BMRRM R&R be required on 7A.1, a launch slip will be required, as there is not adequate time to train both the nominal 7A.1 mission and the BMRRM R&R. The plan is still to launch a spare BMRRM and supporting EVA equipment on 7A.1, and as such, the vice clamp contingency tool and the terminating connectors under development are still required for 7A.1. Launch-on-need requirements and EVA assessments for a BMRRM R&R on UF-1 are now under consideration.

Multilateral EVA Control Board (MECB)

The Multilateral EVA Control Board (MECB) was conducted on May 22, 2001, at the Johnson Space Center (JSC). It was a bilateral meeting between NASA personnel and their Russian colleagues from RSC-Energia, Zvezda and GCTC. There were six key topics discussed. The ISS-2 contingency EVA proposal to remove and replace the Arm Computer Unit on the Space Station Remote Manipulator System was statused. The Safety Tether Enhancement Agreement was approved and will be routed for Russian signatures before it is approved at the SRP. The agreement addresses two fault tolerant tethering and provides rationale for instances when the requirement within SSP 41163 is not being met. The Return to ISS Non-Compliance Report (NCR) was approved and will also be routed for Russian signatures before it is approved at the SRP. The NCR addresses the requirement within SSP 41163 for crew self-rescue and provides rationale for Orlan use until the Orlan SAFER is available. Six updates to the Generic Ground Rules, Requirements and Constraints Document SSP 50261 were approved and will be taken forward to the ISS Program for approval. The updates are contained in section 3.10 Extravehicular Activity Planning under the Ground rules and Constraints section and within section 4.3.2 Extravehicular Activity under the Generic Requirements section. The EVA flight rule for single crewmember EVA was also discussed. The rule allows a single crewmember EVA to be conducted in a contingency scenario. The proposal to have the flight rule rescinded was approved, and a change request will be submitted to the ISS Program. The plan to implement Orlan EVA’s from the joint airlock by ISS-5 was also discussed and approved by the MECB. It was a very productive meeting with key agreements made stemming from several EVA TIM’s conducted both in Russia and at JSC over the past year.

Increment 2 Contingency EVA

An EVA task to remove and replace an Arm Computer Unit (ACU) on the Space Station Remote Manipulator System during the scheduled EVA on June 8, 2001, is being assessed. The current task for the EVA is to transfer the docking cone to the Service Module nadir hatch in preparation for the docking of the DC1. Activities underway for the ACU task assessment include VR evaluation of translation paths and work sites, procedures and techniques to use U. S. tools with the Orlan, NBL runs in both EMU’s and Orlans, and bilateral development of EVA procedures and timelines. Many open issues are being addressed, and an EVA Readiness Review was performed on May 30, 2001. The ISS program is expected to decide by June 4, 2001, whether the ACU task will be added to the June 8, 2001 EVA.

Boot Fit Status

To date, several crewmembers have complained of tight EMU boot fit during EVA. After receiving feedback from the affected crewmembers, it has been determined that the discomfort is most likely being caused by material build-up at a seam which lies across the arch of the foot. Due to various issues, including the fact that the Class III hardware is broken in, the EVA crewmembers do not typically notice this discomfort while training in the NBL. It is theorized that they do not notice the discomfort during Class I fit checks and chamber runs because the crewmembers’ weight compresses the boot and moves the foot away from the problematic seam. To address resolution of the failure that has been opened on this condition, and to minimize the possibility of additional crewmembers experiencing this discomfort on orbit, several steps have been taken. First, the heavy socks that are thought to contribute to the material build-up have been removed from the list of crew preference options. Second, all crewmembers’ boot sizing is being increased by one size, unless a crewmember specifically requests to keep his or her current sizing. Third, all crewmembers are being fit checked in their Class I boots. During these fit checks, procedures have been modified in an attempt to more effectively simulate zero-g EMU fit. The crewmembers will be lifted off of the ground by the donning stand to eliminate the boot compression cased by the crewmembers weight. STS-104/7A crewmembers have all successfully completed fit checks and are ready to fly.

Original signed by

Stephen C. Doering

Acting Deputy Manager

SpaceRef staff editor.