INTERNATIONAL SPACE STATION
Expedition Two Science Operations
Status Report for the week ending August 8, 2001

During the past week, a science team at  NASA's Glenn Research Center in
Cleveland conducted four scheduled tests using the Experiment on Physics of
Colloids in Space.

Excellent data was collected on colloid polymer gas and liquid phases, as
well as the performance of a colloid polymer gel, the science team reported.
A colloid is a system of particles mixed in a fluid.  Examples are paint,
milk and ink.  Colloids are commonly used in industry.  A better
understanding of how they behave could lead to engineering new kinds of
materials.

An experimental device to protect delicate microgravity experiments from
vibrations aboard the International Space Station is undergoing tests of its
full capability this week following repairs on Thursday, August 2.  Flight
Engineer Jim Voss repaired the Active Rack Isolation System (ARIS).  He
replaced one of the eight actuators designed to act like powered shock
absorbers to dampen vibrations.  During his inspection, he determined that a
pushrod operated by the actuator was bent and replaced that also.

Ongoing tests that began last weekend proved that the repair was a success,
including several "hammer tests" in which Voss rapped with a small hammer on
EXPRESS Rack 2, which houses the ARIS system.  Having already completed
7-actuator testing to prove the system's fault tolerance, the team is ready
to begin full 8-actuator testing.

"Jim tapped it a number of times in a number of locations and we monitored
it in real time from the ground," said Naveed Quraishi, manager of the ARIS
ISS Characterization Experiment (ARIS-ICE) at NASA's Johnson Space Center in
Houston.  ARIS-ICE is designed to characterize ARIS' on-orbit performance.
In addition to generating controlled disruptions on and off EXPRESS Rack 2,
ARIS-ICE will enable real-time monitoring of the on-orbit vibration
isolation capabilities of various ARIS configurations.

In June, the ARIS-ICE science team began a series of tests that last 16
hours a day for up to 120 days.  So far, there have been no unanticipated
problems and testing is going according to plan, Quraishi said.  The
actuator and pushrod repair come just in time for this week's Space Shuttle
mission.

"We're very excited to be at this point because we are ready to do a full-up
test during mission 7A.1 docked operations," he said.  "When the shuttle
docks, that will put an enormous impulse into the whole Station.  We're
hoping to see the performance of the ARIS system when that happens.  It will
be orders of magnitude worse than anything we'll ever see in normal science
operations, when experiment runs will be timelined between dockings."

Photography targets uplinked to the Station for the Crew Earth Observations
program this week included lakes and river levels where the Tigris and
Euphrates Rivers descend to the plains of Syria; land use, wetlands, and
sediment plumes in the Irraddy River Delta of Burma; and river levels and
water diversion projects in the Yellow River delta of China.

On Monday, August 6, the Expedition Three cadre officially took over
operations from the Expedition Two team.  As part of that handover, normal
communications between the Payload Operations Center and telescience centers
on the ground and the Space Station were interrupted briefly for the third
time in the Station program while computers on the ground and computers on
the Station were converted to run the programs needed to run Expedition 3
experiments.  The new programs also allow the science and control teams to
continue operating Expedition Two payloads until the mission is completed.
Similar updates were conducted between the 5A.1 and 6A missions and between
the 6A and 7A missions.

Coming up this week, the crew will deactivate the Phantom Torso and
Dosimetric Mapping radiation measuring experiments and ready them for return
on the Shuttle.  The Bonner Ball Neutron Detector will remain on the Station
to measure radiation levels but will be moved to a new location in the
Destiny lab module.

Normal operations continued this week on the Interactions, Commercial
Protein Crystal Growth, Microgravity Acceleration Measurement System and
Space Acceleration Measurement System experiments.