The STS-105 mission to deliver the third resident crew to the ISS is scheduled to launch tomorrow at 4:38 p.m. Central time as the ISS sails over the Southern Ocean south of Adelaide, Australia at an altitude of around 240 statute miles.
Discovery's Commander, Scott Horowitz, Pilot Rick Sturckow, and Mission Specialists Pat Forrester and Dan Barry are ready to ferry Expedition Three Commander Frank Culbertson, Pilot Vladimir Dezhurov and Flight Engineer Mikhail Tyurin to the Station for a four-month mission, succeeding Usachev, Voss and Helms, who have been aloft since March 8.
Discovery was cleared for launch earlier this week by Shuttle managers after reviewing the status of fuel injector units used in the hydraulic power units that steer the Shuttle's solid rocket booster nozzles during the first two minutes of powered flight.
Last night aboard the ISS, one of three command and control computers (C & C 1) which is used as a backup for the operation of some Station systems experienced a problem reading its hard drive, or Mass Storage Device. The hard drive stores commands for a variety of vehicle activities on the U.S. segment of the complex. Flight controllers attempted to reboot the computer with no success and are continuing efforts to bring it back into operation. This computer has lost only some of its functional capability. The Station's primary computer (C & C 3) is operating normally, however, and a third computer (C & C 2) is being transitioned from standby status to act as the backup for C & C 3.
A newly refurbished command and control computer had already been manifested to be launched on Discovery to the ISS as a spare, and would be installed for operation, if required. The backup computer glitch has had no impact on Station operations and will not affect the joint mission to deliver the new Expedition crew to the orbital outpost.
As Usachev, Voss and Helms prepared to handover command of the Station to a new crew, Russian engineers prepared two vehicles for launch right after the STS-105 mission. At the Baikonur Cosmodrome in Kazakhstan, a Progress resupply ship is being readied for launch on August 21 to deliver food, fuel and supplies for the new Expedition Three crew. It is scheduled to dock to the aft docking port of the Zvezda Service Module on August 23, one day after the current Progress attached to the ISS is jettisoned. And the newest ISS module, a Russian Docking Compartment named Pirs, the Russian word for pier, is in the final stages of preparation for launch on September 15 to link up to the earthward facing docking port of Zvezda. It will provide a new docking port for future visiting Russian vehicles.
In addition to packing to come home, the Expedition Two crew continues to oversee a variety of science investigations.
The International Space Station (ISS) is orbiting at an altitude averaging 240 miles (385 km).