XA/EVA Project Office Weekly Activity Report December 6, 2001
Extravehicular Mobility Unit/Premature EMU Battery Termination From Joint Airlock (JAL) Battery Charger (BCA):
On November 29, 2001, charging of EMU Batteries SN 2012 and SN 2014 in the ISS joint airlock was terminated after 2 hours on an 18-hour charge cycle. The BCA was charging through the EMU Service and Cooling Umbilical (SCU) with the batteries in the EMU. Initial indications are that the cut-off voltage settings in the BCA may be set slightly low for this charging configuration. SSATA testing is being conducted to further understand this failure. In order to insure charging capability of the EMU battery on orbit, the two batteries in question will be charged in the Battery Stowage Assembly (BSA) this week. In addition the Mid-deck Battery Charger was certified Monday, December 3, 2001, providing redundant capability on-orbit. The failure investigation is ongoing and XA expects engineering recommendations within two weeks.
Impacts to Hubble Space Telescope (HST) Portable Foot Restraint (PFR) and Manipulator Foot Restraint (MFR) Due to Revised Vibrations Loads Analysis (VLA):
The HST PFR and MFR hardware was certified on November 2, 2001 based on the original VLA. A subsequent update to the VLA load set was delivered which showed an increase of 8 to 10% at the sidewall carrier where the HST PFR and MFR are stored for launch and landing. The current certification has a small margin, and XA is concerned that there is risk to the current hardware stowage location with the approved factor of safety. A revised loads analysis is scheduled to be complete by December 13, 2001.
Russian Segment EVA:
During mating of the Progress to the aft end of the Service Module on November 28, 2001, the Progress could soft dock but was not able to hard dock. The Russians determined, that debris was lodged between the two vehicles, keeping the Progress from hard docking. An EVA tiger team was formed to work with the Russian EVA specialists to put together plans/procedures to conduct an EVA. The major issues addressed were translation paths, potential contamination, sharp edges, access to the debris, pinch hazards, and a complement of both Russian and US tools to perform the task. An EVA readiness review was conducted at the IMMT, and all issues were successfully addressed. The EVA occurred on December 3, 2001, with the EVA crewmembers successfully removing what is apparently the seal from the 5 Progress vehicle. The docking probe was subsequently retracted and the hooks engaged for a hard dock. No detectable contamination was observed on the Orlan suits or tools prior to ingress or post EVA.
Mobile Transporter Energy Absorber (MTEA):
All Certification and Acceptance testing has been completed on the MT EA. Hardware was shipped from JSC to KSC on Friday, November 30, 2001, to support ISS S0 Truss Element integration activities scheduled for this week. Acceptance Data Pack on schedule to complete by Thursday, December 6, 2001, prior to final installation.
Original signed by:
Steve Doering for
G. Allen Flynt
Manager
