Station science team set for change of expeditions
Posted: August 5, 2001

The international space station. Image: NASA
The Space Station crew and ground teams are preparing to conclude one successful science expedition and begin another.

"We're coming down the home stretch for Expedition Two, with a few activities remaining before we return the rest of the science on 7A.1 Shuttle mission," said John Uri, lead increment scientist for Expeditions Two and Three, from NASA's Johnson Space Center in Houston."And now we're gearing up to begin the research on Expedition 3."

The 7A.1 Station mission, scheduled for an August 9 launch, will carry the Expedition Three crew to the orbiting research facility and return home with the Expedition Two crew after a five month tour of duty in space.

Three Expedition Two experiments returned home aboard Space Shuttle Atlantis recently. Expedition Three will have 18 experiments, including 10 continuing from Expedition Two, as well as eight new experiments.

About 11 hours of crew time are allocated for remaining experiment activities this week, not counting task list items that the crew can do as time permits. In fact, the crew has accomplished a number of payload activities using the task list.

"The crew has taken on the research program as their own," Uri said."They have been able to catch up or get ahead on work and have given up their own time. The Expedition Two crew has set the bar very high."

On Monday, July 30, the crew completed stowing the Middeck Active Control Experiment for return. They also received a new list of targets for the Crew Earth Observation photography program, including a geologic fault zone in Tanzania and the Antarctic ice sheet and icebergs near the South Sandwich Islands. The science team confirmed that the crew was also able to capture an image of the Mt. Etna volcano in Sicily.

They were also scheduled this week to take documentation photos of the Protein Crystal Growth Enhanced Gaseous Nitrogen Dewar experiment, which arrived on the recent Shuttle mission and was located in Zarya, the Russian FGB module.

The crew this week also has continued to recharge batteries for the Dosimetric Mapping experiment's portable radiation sensors, transfer radiation data to a portable computer for later transmission to the ground, and fill out their weekly questionnaire for the Interactions study dealing with interpersonal and cultural relationships among the crew during the Expedition.

A priority for the science team and the crew today is replacing a possible faulty actuator on the Active Rack Isolation System, an experimental device designed to protect delicate microgravity experiments from vibrations caused by crew activities and powered equipment. ARIS uses eight actuators, designed to act like powered shock absorbers to damp vibrations before they reach experiments. Ground controllers have been running tests of the device with seven actuators to demonstrate its fault tolerance.

Telescience activities controlled by scientists on the ground, are continuing with a pair of vibration measuring experiments the Microgravity Acceleration Measurement System and the Space Acceleration Measurement System, as well as the Physics of Colloids in Space experiment.

Transition activities continue as the Expedition Three cadre at the Payload Operations Center prepares to take over for Expedition Two controllers on August 6. Controllers are continuing to update the software on board the Station to recognize the new payloads, and control software on the ground is undergoing similar updates.