Halsell and his crew performed the rendezvous and docking with the station by the book, docking on target at 11:31 p.m. CDT Saturday. Although Atlantis is now firmly attached to the station, the astronauts will not enter the new outpost until Monday, turning their immediate attention instead to a six and half-hour spacewalk to begin late tonight.
Astronauts Jim Voss and Jeff Williams will perform tonight's spacewalk to install the final part of a Russian-built crane on the station's exterior; replace a faulty communications antenna; and install various cables and handrails. Following the docking, Voss and Williams spent several hours this morning preparing the tools and equipment they will use for the sojourn outside and double-checking the spacewalk plans with the rest of the crew.
The crew also lowered the air pressure inside Atlantis from the standard sea-level pressure of 14.7 pounds per square inch to 10.2 pounds per square inch, a pressure equivalent to that felt at an altitude of 10,000 feet on Earth. The lower cabin pressure helps Voss and Williams purge nitrogen from their bodies to avoid decompression sickness when they go to the 4.2 pounds per square inch, pure oxygen atmosphere of the spacesuits this evening.
The International Space Station remains in good condition, ready for the crew to enter on Monday to start several days of maintenance and unloading of supplies. As the crew's waking hours wound down early this morning, Mary Ellen Weber, who will oversee much of the transfer of equipment, and Halsell made some early preparations of the docking system for the eventual entry into the station.
The crew will begin a sleep period at 8:11 a.m. and awaken at 4:11 p.m. for a fourth day in space, a day devoted to the spacewalk. Voss and Williams are planned to begin donning their gear and suits at 6:11 p.m., leading to a predicted exit from Atlantis' airlock hatch at 9:31 p.m. During the spacewalk, Williams' suit will be distinguishable from Voss' suit by red stripes around the legs. The astronauts are scheduled to conclude the spacewalk at 4:01 a.m. Monday.
Atlantis is operating well with flight controllers reporting no problems of significance for any of the mission's activities. The shuttle and station are in an orbit with a high point of 209 statute miles and a low point of 203 statute miles, circling Earth every 91 minutes.