INTERNATIONAL SPACE STATION STATUS REPORT #01-21
                   Wednesday, June 27, 2001 - 5 p.m. CDT
                            Expedition Two Crew

 As Shuttle and International Space Station Program managers prepare to
 meet to select an official target launch date for Atlantis' STS-104
 mission to the complex, the Expedition Two crew continues to test the
 station's robotic arm in preparation for its first official task of
 permanently installing the Airlock onto the Unity module.

 The face-to-face Flight Readiness Review at the Kennedy Space Center
 Thursday is expected to result in a launch target date for Atlantis at
 4:04 a.m. CDT, July 12. Pending completion of the robotic arm checkout on
 orbit, Atlantis will arrive with the newest component of the station late
 in the evening of July 13. The Airlock is a critical component allowing
 Extravehicular Activity (EVA), or space walks to be conducted using U.S.
 spacesuits or Russian Orlan spacesuits without the presence of the
 shuttle.

 The Airlock also will add an additional 1,200 cubic feet of volume to the
 station, bringing its size to about 12,000 cubic feet of volume. The
 six-and-a-half-ton module, built by Boeing at NASA's Marshall Space
 Flight Center, can only be attached to the station using the new
 Canadian-built robot arm that was delivered to the station on the most
 recent shuttle mission in April.

 Since that time, the Canadarm2, as it's known, has been undergoing an
 extensive on-orbit checkout. Several problems with the testing led to
 launch delays, but those issues have been resolved and the arm has
 operated flawlessly for several weeks. In the event of a recurrence of
 the most serious of the problems, which was a communications error in the
 shoulder pitch joint's backup electronics, a software patch essentially
 telling the robotic arm's electronics to bypass the nuisance fault has
 been loaded into station computers, which likely will solve the problem
 should it surface again.

 Extensive reviews by engineers from NASA, the Canadian Space Agency and
 its prime robotics contractor - MD Robotics - concluded that the
 communications error between Canadarm2's shoulder pitch joint and the
 arm's main computer commanding unit was attributable to an intermittent
 problem with a computer chip in the joint's electronic system and not a
 problem with joint itself.

 Expedition Two Flight Engineers Jim Voss and Susan Helms will conduct an
 additional dress rehearsal of the Airlock installation task Thursday,
 following an identical run a week ago.

 In preparation for launch, the STS-104 crew is at the Florida spaceport
 for its traditional countdown dress rehearsal that concludes Friday.

 Expedition Two Commander Yury Usachev, Voss and Helms continued a variety
 of science investigations this week with more than 25 hours of experiment
 work budgeted for the crew. Oversight from the ground is handled by the
 Payload Operations Center at NASA's Marshall Space Flight Center in
 Huntsville, AL, except for the Human Research Facility, which is
 monitored and controlled from the Telescience Support Center (TSC) at the
 Johnson Space Center, Houston. For details on ISS science, visit the
 following website:
 http://www.scipoc.msfc.nasa.gov.

 The International Space Station is orbiting at an altitude averaging 240
 miles (385 km). The next ISS Status Report will be issued Thursday, July
 5, or as mission events warrant.