ISS logo. Photo: NASA

On-orbit activities of the International Space Station continue to focus on electrical power system management as engineers on the ground train their attention on the processing and outfitting of Atlantis for its first visit to space and an orbiting outpost since it returned from the Mir Space Station in 1997.

Atlantis is scheduled to be moved to the launch pad early Saturday in preparation for the STS-101 launch currently set for no earlier than April 17. With processing virtually completed on the orbiter, planners continue to massage the details of hardware on the station that will be changed out to preserve and extend the Zarya module through the end of the year as the ISS awaits the arrival of its next pressurized module -- the Zvezda service module.

Zvezda is scheduled to launch atop a Russian Proton launch vehicle between July 8 and 14. The module is in its final months of processing at the Baikonur Cosmodrome in Kazakhstan.

The ISS continues to operate without any major systems failures as it circles the Earth every 92 minutes in an orbit of 232 by 221 miles. The station has completed 7,645 orbits since Zarya was launched in November 1998.

Meanwhile, the first crew to officially turn the International Space Station into a home is scheduled to launch to the outpost in late October following Zvezda's launch and docking in July. Zvezda (the Russian word for "Star") provides life support, command and control, and the early living quarters for the crew.

The adjustments to the official near term assembly sequence were agreed to by the International Partners and participants at a recent Space Station Control Board meeting. The United States, Russia, Canada, Japan, the European Space Agency, Italy and Brazil were represented at the meeting.

The first crew of three includes Commander William Shepherd, Soyuz Commander Yuri Gidzenko and Flight Engineer Sergei Krikalev. They will launch to the ISS from Baikonur atop a Soyuz rocket and dock two days later for a three-to-four-month stay.

Following is the updated near term assembly sequence through August 2001 with no-earlier-than target launch dates. The complete assembly sequence can be viewed on NASA's Human Spaceflight Website at: http://spaceflight.nasa.gov/station/assembly/flights/chron.html.