The International Space Station is contrasted against the cloud-covered home planet and the darkness of space in this post-undocking view from STS-101. Photo: NASA

Flight controllers in Houston and Moscow are beginning to prepare of the International Space Station for the launch of its third major component, the Zvezda Service Module, expected in a few weeks.

The Station continues to operate well and flight controllers have noted no problems with any systems onboard. Activities planned this week include a health check of the Kurs automatic docking system, the primary system the Station will use to rendezvous and dock with the Zvezda module once it reaches orbit. Zvezda remains targeted for launch on a Russian Proton Rocket from the Baikonur Cosmodrome, Kazakstan, between July 10-12. A final launch date for Zvezda is expected to be announced following a General Designer's Review meeting of Russian and United States station managers to be held in Moscow on June 26.

Flight controllers in Moscow are continuing an analysis of results from a test conducted last week of the backup manual docking system aboard the station. The test showed no indications of any problems with the systems aboard the spacecraft. However, it is believed that a ground communications problem may have prevented some test commands from reaching the station. The backup manual rendezvous and docking system, called the TORU system, would only be used if an automatic docking with Zvezda were unsuccessful.

Next week, commands will be sent to the station to begin transferring propellants to appropriate tanks in preparation for engine firings that will be conducted for the rendezvous and docking. A total of 1,650 pounds (748 kilograms) of propellants will be moved between tanks in two seven-hour-long procedures in preparation for the rendezvous with Zvezda.

The International Space Station is in an orbit with a high point of 245 statute miles and a low point of 230 statute miles (394 x 371 kilometers), circling Earth every 92 minutes.