STS-104
Report # 11 
 Tuesday, July 17, 2001 - 7:00 a.m. CDT 
 
 Shuttle and station crews set aside work on a leaky ventilation valve and
pressed forward with activation of the new Quest airlock and a dry run of
the steps theyíll use for the first space walk using the new station
doorway to space.

The practice run included a successful lowering of the airlockís pressure
to 10.2 pounds per square inch for the first time in space.

Lead Flight Director Paul Hill said troubleshooting on the valve -- and
work the day before to get air bubbles out of an airlock water cooling
line -- have put the combined crew about half a day behind its timeline.
Among the tasks delayed was a relocation of the hatch from the junction of
the airlock and the Unity module to its final position between the
airlockís crew and equipment lock sections.

The second space walk of the flight remains on schedule for Tuesday night.
Mission Specialists Mike Gernhardt and Jim Reilly are scheduled to step
out of the space shuttleís airlock about 9:30 p.m. The objective of the 5
W* hour foray is to mount one high-pressure oxygen and one high-pressure
nitrogen tank on the shell of the new airlock to provide consumables that
would allow expeditioners to leave the station in American space suits for
construction and maintenance work without a shuttle present.  Russian
space suits can be used from the airlock as well.

The crews closed the hatches between the two spacecraft at 6:30 a.m.
Tuesday to begin lowering Atlantisí cabin pressure to that same 10.2
pounds per square inch mark. This measure helps purge nitrogen bubbles
from the space walkersí bloodstreams, and is augmented by the space
walkers pre-breathing pure oxygen. All crewmembers reviewed the procedures
for the space walk prior to closing the hatch between the shuttle and the
stationís Destiny Laboratory.

Mission Specialist Janet Kavandi and Expedition Two Flight Engineer Jim
Voss took the lead in troubleshooting the suspected leak in an Intermodule
Ventilation (IMV) assembly. The series of fans and valves circulates air
between station modules and connects the airlock to the stationís
environmental control and life support system. The pair wasnít able to
pinpoint the problem with the valve, but did install a cap that stopped
the leak. Should replacement be necessary, several valve replacement
options are available to the flight control team and crew onboard.

The delays have led flight managers to study the possibility for an extra
day of docked operations and a shuttle mission extension to ensure all of
the missionís work can be completed.

Shuttle Commander Steve Lindsey, Atlantisí Pilot Charlie Hobaugh and
Station Commander Yury Usachev took time late Monday night to answer
questions from reporters from CBS, Space.com and KNBC-TV of Los Angeles.

The eight people on orbit are scheduled to go to bed about 8 a.m. and
awaken at 4:04 p.m. The next mission status report will be issued about 6
p.m. Tuesday or as events warrant.