After spending the day unstowing final items and installing air ducts for the Russian-built Zarya control module and the U.S.-built Unity module, Commander Bob Cabana and Russian Cosmonaut Sergei Krikalev closed the hatch to Zarya at 4:41 p.m. Central time. They closed a series of additional hatches as the crew made its way back to Endeavour, finally swinging the door to Unity shut at 6:26 p.m. This ended the first excursion by astronauts into the international outpost, an excursion that lasted 28 hours and 32 minutes.
Left behind were tools, supplies and clothing for the crew that will visit the station during the next shuttle assembly flight in May, and for the first crew members who will establish a permanent occupancy of the station in January 2000.
Back inside Endeavour, the astronauts completed preparations for a third and final space walk Saturday by Jerry Ross and Jim Newman to tidy up cable configurations. Ross and Newman plan to disconnect several jumper cables used to route power from Zarya to Unity before permanent electrical connections were made and disconnect cables used to permanently lock the two modules' docking mechanisms together. In addition, tool bags will be stowed on the side of Unity's uppermost Pressurized Mating Adapter for use by space walkers Tammy Jernigan and Dan Barry on the STS-96 assembly mission in May.
Near the end of Saturday's space walk, Ross plans to use a grappling hook to try to free the second of two jammed antennas that are part of Zarya's backup rendezvous system. Just as Newman did on Wednesday, Ross will use the device to pry the balky antenna free to its fully extended position while attached to the end of Endeavour's robot arm.
The space walk is scheduled to begin about 3:06 p.m. Central time Saturday, but could get under way earlier if Ross and Newman are ahead of schedule in their space walk preparations.
With all of their work complete, Endeavour's crew members will undock from the newly outfitted station at 2:25 p.m .Sunday, leaving the 35-ton complex to fly on its own for the next five months. Through an S-band communications system installed in Unity by the astronauts, station flight controllers will be able to monitor the health of Unity and Zarya as the complex orbits the Earth.
The astronauts will begin an eight-hour sleep period at 2:36 a.m. Central time Saturday and will be awakened at 10:36 a.m. to begin space walk preparations.
Endeavour and the International Space Station are orbiting the Earth at and altitude of 246 statute miles with all of their systems in excellent shape.