STS-80
Report # 26 
10 A.M. SATURDAY, NOVEMBER 30 
 
   The STS-80 Mission Management Team concluded at its 8 a.m. meeting
today that around-the-clock analysis and testing so far has not
identified a most likely cause of a jammed hatch that has prevented
astronauts aboard the orbiter Columbia from conducting the first of
two planned space walks.

   The MMT, chaired by Loren Shriver, Shuttle Launch Integration
Manager, asked engineering analysis teams at JSC, the Kennedy Space
Center, and at Rockwell in Downey, Calif., to continue efforts to
identify the likely cause of the hatch problem and report back at 2
p.m. today.

  Investigations continue to center on possible problems with the
linkage and latch mechanisms located on the payload bay side of the
airlock hatch (called the "B" hatch) or with the gear actuator
mechanism driven by crew operated handles on either side of the hatch.
Analysis teams also are looking at the possibility of a small
misalignment of the hatch with respect to the orbiter structure which
might have resulted at installation or which could be caused by slight
deformation of the orbiter structure in space.

  A decision to proceed with a spacewalk today will hinge on progress
in the next few hours before the crew awakens at identifying a likely
cause of the problem and assuring that any corrective action attempted
will not adversely affect the safe operation and sealing of the hatch.
The crew wakeup is scheduled for 2:56 p.m. CST.

  NASA managers are viewing the hatch problem not only from the
perspective of completing the two space walks scheduled for the
flight, but also to develop a plan for opening the hatch in the
unlikely event that a contingency EVA becomes necessary, for example,
to close and latch the payload bay doors before entry.

  If additional time is required for analysis and testing of the
airlock hatch, a decision could be reached at the 2 p.m. MMT to defer
the EVA decision for another 24 hours and to look at dropping a second
EVA originally planned to follow two days after the initial EVA.

  An STS-80 mission status briefing is planned for 4 p.m. today at the
Johnson Space Center and on NASA Television.

  NASA Johnson Space Center Mission Status Reports and other
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