Endeavour undocked from the station at 11:28 a.m. CST as the spacecraft flew 240 statute miles above the Indian Ocean off the Australian coast. Pilot Mark Kelly flew Endeavour through a half-circle of the station before firing jets to leave the vicinity.
Before undocking, Endeavour's jets were fired in a series of small pulses beginning at 8:55 a.m. CST to raise the altitude of the station about three quarters of a mile. The maneuver ensures the station will fly well clear of an old Russian rocket body that had been predicted to potentially pass close to the complex later this weekend. The final small reboost by the shuttle, coupled with three larger reboosts done earlier in the week, means the station was raised a total of more than nine statute miles by Endeavour.
The new station crew, Expedition Four Commander Yury Onufrienko and Flight Engineers Dan Bursch and Carl Walz, said goodbye to Endeavour's crew and the departing Expedition Three crew and closed hatches between the spacecraft at 7:16 a.m. CST. Now en route home, Expedition Three Commander Frank Culbertson, Pilot Vladimir Dezhurov and Flight Engineer Mikhail Tyurin completed 117 days as the primary station crew and spent 125 days aboard the station overall. When Endeavour lands on Monday, they will have spent a total of 129 days in space.
The crew members aboard Endeavour had several hours off duty after departing the station, a break from a very busy pace moving tons of supplies between the shuttle and station during the past week. Sunday's activities will focus on checking out systems used during descent and making preparations for a landing on Monday. Endeavour is set to land at the Kennedy Space Center, FL, about 11:55 a.m. CST Monday. The weather forecast predicts generally acceptable conditions except for a chance of rain showers in the vicinity of the landing site. Flight controllers determined today that all three Inertial Measurement Units on Endeavour, the primary navigation systems for the shuttle, would be usable for landing. One of the three units had been taken off line two days ago due to a brief fault. However, the unit has worked well since that time. Even if the problem were to recur, it would not affect Endeavour's entry and landing since the shuttle can operate with only one such unit if necessary. Endeavour's crew will begin a sleep period at 7:19 p.m. CST and awaken at 3:19 a.m. CST Sunday.