Expedition 9 Commander Gennady Padalka, Flight Engineer Mike Fincke, and European Space Agency astronaut André Kuipers of the Netherlands are at the launch site, ready to go. The ISS Soyuz 8 spacecraft was mated with its rocket booster today, and the pair will be rolled out to the launch site Saturday. Launch remains on schedule for 10:19 p.m. CDT April 18.
Expedition 8 Commander Mike Foale and Flight Engineer Alexander Kaleri spent the week preparing the Station for the replacement crew's arrival, packing for the trip home after six months on orbit, and wrapping up work on several experiments.
Foale and Kaleri supported a test of their ISS Soyuz 7 return vehicle's maneuvering jets, which verified that all thrusters are ready to support undocking, deorbit burn and re-entry. Russian flight controllers monitoring the test reported seeing evidence of the same helium leak that was initially seen in telemetry during the Expedition 8 crew's launch in October. On Friday, Russian controllers conducted an additional test of the helium system used to pressurize the Soyuz fuel tanks to gather additional data on the leak rate, which is believed to have increased some over previous observations. Russian flight controllers are continuing to evaluate data from the tests. However, no impact to the normal Soyuz descent and landing is anticipated.
Kaleri also spent several hours in the Soyuz descent module changing out a pair of ventilation and humidity removal fans. He replaced the fans with a spare stored in the Zarya control module and verified that they are working well. The old fan package, which has one working fan, will be retained on the Station as a spare.
Foale conducted a final session with the Hand Posture Analyzer experiment on Thursday, after wrapping up work with the Pore Formation of Materials Investigations (PFMI) and the Foot/Ground Reaction Forces during Space Flight (FOOT) experiments last week. The Hand Posture Analyzer is an Italian investigation looking at how humans use their arms, wrists and hands for reaching and grasping in microgravity. Final sessions with the RENAL kidney stone experiment were conducted Friday.
Foale also spent several hours Wednesday setting up and activating ESA's HEAT experiment in the Microgravity Science Glovebox for his visiting colleague, Kuipers. HEAT will evaluate whether a grooved heat pipe can be used effectively in the weightlessness of space to transfer heat from hot surfaces, such as electronic devices, to cold surfaces, such as radiator panels.
Otherwise, the crew conducted a series of routine periodic fitness evaluation tests on themselves, and collected samples of a variety of environmental factors inside the Station for return to Earth and evaluation by scientists on the ground when they return home.
The Expedition 9 crew is scheduled to rendezvous and dock with the Station at 12:04 a.m. CDT Wednesday. Hatches will open and the five spacefarers will greet each other at 1:25 a.m. that morning, beginning more than a week of joint operations.