12.01.97

Monday, December 1, 1997 - 7:00 p.m. CSTSTATUS REPORT: STS-87-25

STS-87 MISSION CONTROL CENTER STATUS REPORT # 25



STS-87 mission managers Monday afternoon decided to add a second 
spacewalk to this mission, giving astronauts and EVA designers more 
confidence in techniques which will be important to assembly of the 
International Space Station.



Astronauts Winston Scott and Takao Doi will exit Columbia’s 
airlock at approximately 2:15 a.m. CST Wednesday for a five-hour 
spacewalk which will repeat part of the crane operations, handling 
the smaller of the boxes which represent objects it will have to move 
during Space Station assembly.



Greg Harbaugh, acting manager of the EVA Projects Office at Johnson 
Space Center, explained in a press conference Monday that planners 
want to get as much confidence as possible that the movement of ORUs 
(Orbit Replaceable Units) can be done successfully. He noted that 
handling of the boxes during the first spacewalk did not give EVA 
designers all the information they needed. The original spacewalk 
timeline was modified last week to accommodate the retrieval of the 
SPARTAN satellite.



Another component of the second EVA will be checkout of the AERCAM 
SPRINT flying video camera which will be used during Space Station 
assembly and operations as a second point of view to observe work 
outside the station.



With the juggling of the crew timeline to add the second EVA, other 
mission activities have been rescheduled. After the astronauts awaken 
tonight at about 7:45 p.m. CST, their flight day 13 will include 
three hours of PEP operations (Particle Engulfment and Pushing), the 
MEPHISTO furnace experiment and SOLSE (Shuttle Ozone Limb Sounding 
Experiment) observations. The in-flight crew press conference has 
been moved earlier, now scheduled to begin at 4:36 a.m. CST. Media at 
Johnson Space Center in Houston, Kennedy Space Center in Florida and 
in Kiev, the Ukraine, will participate.



Just before 9 a.m. CST Tuesday, Columbia’s crew will reduce the 
cabin atmospheric pressure to 10.2 psi, giving Scott and Doi 16 hours 
of advance pre-breathe time which reduces their in-suit pre-breathe 
to just one hour.



The next status report will be issued at approximately 6 a.m. CST 
Tuesday.

	
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