The night sky's third brightest object -- the international space station -- now is under computer control from its newest addition, the Zvezda service module, following a "handover" of that responsibility this weekend from the Zarya control module.

An artist's concept of the current make up of the international space station with Zvezda on the left, Zarya in the center and Unity is the right. Photo: NASA

Zvezda now is handling all attitude maneuvers of the 60-ton complex through its own Motion Control System following the automatic docking last Tuesday night. Since then, leak checks have been performed verifying a tight seal between Zarya and Zvezda.

Additionally, commanding through the Unity node's early communications system was transferred to Zvezda as well, meaning that equipment can be powered via ground commands sent from Moscow, through Houston and up to the station. Russian ground stations continue to serve as the primary method of sending commands and receiving data from the ISS. Prior to the transition of computer control, Zvezda's three computers were rebooted to allow them to synchronize properly before the formal swap.

The remainder of this week will see flight controllers oversee routine battery cycling aboard Zarya and an automatic docking system test in preparation for the arrival of the Progress supply vehicle being readied for launch on Sunday.

The Progress, in final processing at the Baikonur Cosmodrome in Kazakhstan, will ride to orbit on a Soyuz rocket with liftoff tentatively scheduled for 2:30 p.m. Eastern Time on Aug. 6. At present, docking is scheduled for 3:46 on the afternoon of Aug. 8. NASA TV will cover the docking live, but not the launch.