STS-104
Report # 15 
 Thursday, July 19, 2001 - 6 a.m. CDT 
 
 Astronauts aboard the International Space Station complex successfully
replaced a leaky air circulation valve and moved a hatch into position for
the first space walk out of the new Quest airlock.

That space walk is scheduled to begin about 10:30 p.m. Friday, pending a
successful leak check of the crew lock while the crew sleeps today.
Mission Specialists Mike Gernhardt and Jim Reilly will attach a fourth and
final supply tank to the airlockís exterior, and move on to some get-ahead
tasks made possible when they were able to attach a bonus third tank
during Wednesdayís space walk. Tasks added to Fridayís space walk include
an inspection of one of the stationís solar array swivels and inspection
of the Floating Potential Probe that measures plasma levels around the
solar arrays.

STS-104 Commander Steve Lindsey and Expedition Two Flight Engineer Jim
Voss finished replacing the Intermodule Ventilation (IMV) Assembly valve
in the station's Unity module about 7:30 p.m. Wednesday. With help from
station Commander Yury Usachev, they replaced the leaking valve with
another from the Destiny laboratory that wonít be needed until the
stationís second node arrives in 2003.

Voss, Mission Specialist Janet Kavandi and Susan Helms moved the hatch
from its initial location between the Unity module and the airlockís
Equipment Lock to between the Equipment Lock and Crew Lock. The Equipment
Lock will be used for storing and servicing space suits, while the Crew
Lock will serve as the exit to space.

Usachev also worked with one of the stationís payload computers,
performing maintenance on several of the stationís Russian systems, and
Kavandi, Gernhardt and Reilly worked to transfer items between the shuttle
and station while getting equipment and space suits squared away in the
airlock. Helms also changed out a Command and Control computer that had
been temporarily installed in place of a payload data computer in Destiny.
The payload computer was cannibalized during the STS-100 and retasked when
all three of the stationís command computers broke down. The old computer
will be returned to Earth on Atlantis for testing and analysis.

Lindsey and Pilot Charlie Hobaugh gave the station another boost using the
shuttleís reaction control system jets, increasing the stationís orbit
about 5 miles to 244 x 240 statute miles. It was the final reboost planned
for this mission.  Atlantis will leave the station later this week about
10 miles higher than when it arrived.