Cape Canaveral, Fla. Space shuttle Atlantis closed in for a rendezvous today with the international space station, a complicated job made even tougher by a failed navigation device.
One of Atlantis' two star trackers was deemed unusable Saturday, forcing commander Terrence Wilcutt and his co-pilot, Scott Altman, to add a couple of flip-flop maneuvers to their repertoire.
"It adds a little bit of complexity," flight director Phil Engelauf said.
The linkup was scheduled to take place about 1 a.m. CST today 220 miles above Kazakstan.
Although still uninhabited, the space station has expanded since astronauts last visited in May. The arrival of the Russian control module, Zvezda, 1 1/2 months ago nearly doubled the space station's size. A Russian supply ship carrying toilet components, oxygen generators and other gear quickly followed.
Atlantis' seven astronauts and cosmonauts will unload the supply ship as well as the shuttle later this week. They will install as much of the equipment as possible to ease the burden for the first permanent residents, who are due to move in at the beginning of November.
In preparation of Atlantis' arrival, flight controllers turned on the heaters inside the U.S. segment of the space station.
The star-tracker failure, detected shortly after Friday's launch, meant extra work for the two shuttle pilots.
Wilcutt and Altman rolled Atlantis 90 degrees once the shuttle was about 45 miles from the space station late Saturday. Then they flipped it back into the proper position for the final approach. The switch in position allowed the working star tracker, which points out toward the left cockpit window, to lock onto the space station and provide all the necessary navigation data.