Endeavour's astronauts wrapped up the first visit inside the International Space Station and prepared it for undocking, closing the hatches for the final time to the new complex before it is left to fly unpiloted for the next five months on Sunday.
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, then closed a series of additional hatches as they and their crew mates made their way back to Endeavour, finally swinging the door to Unity shut at 6:26 p.m. to complete the first excursion by astronauts into the international outpost, an excursion which lasted for a total of 28 hours and 32 minutes.
Left behind were tools, supplies and clothing for the next crew of astronauts which 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 spacewalk Saturday by Jerry Ross and Jim Newman to finish the configuration of cables and connectors between Unity and Zarya. Ross and Newman plan to disconnect several jumper cables which were used to route power from Zarya to Unity before permanent electrical connections were made between the two spacecraft and will disconnect cables which were 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 spacewalkers Tammy Jernigan and Dan Barry as part of their work on the next shuttle assembly flight to the station on the STS-96 mission in May.
Near the end of Saturday's spacewalk, Ross plans to use a grappling hook to try to free the second of two jammed antennas which 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 affixed to the end of Endeavour's robot arm.
The spacewalk is scheduled to begin Saturday at about 3:06 p.m. Central time, but could get underway earlier if Ross and Newman are ahead of schedule in their spacewalk preparations.
With all of their work complete, Endeavour's crew members will undock from the newly outfitted station Sunday at 2:25 p.m., 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 on a frequent basis in the months ahead as the complex orbits the Earth.
The astronauts will begin an eight-hour sleep period at 2:36 a.m. Central time and will be awakened at 10:36 a.m. to begin spacewalk 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.
The next STS-88 mission status report will be issued Saturday morning following crew wakeup.
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