Pilot Rick Sturckow separated Endeavour from the station at 2:25 p.m. Central time, firing the shuttle's jets to place the orbiter 450 feet above the outpost. Sturckow then initiated a nose-forward flyaround of the station as shuttle TV cameras captured spectacular views of the two station modules framed against the blue backdrop of the Earth.
Less than an hour and a half after undocking, at 3:49 p.m., Sturckow fired Endeavour's jets one final time as the orbiter passed 450 feet below the complex, separating for the final time as the station faded from view along the horizon. More than six hours after undocking, Endeavour trailed ISS by some 70 s.m., increasing its distance from the station at about 19 s.m. every orbit.
International Space Station flight controllers at Mission Control, Houston and at the Russian Mission Control Center in Korolev, outside Moscow, will now spend the next five months monitoring the station's systems and awaiting the launch of Discovery on the STS-96 mission. STS-96 will see a multinational crew of seven astronauts return to the station in a logistics resupply flight which will include at least one spacewalk to attach additional hardware to the new orbiting facility.
Late Sunday, flight controllers commanded the station into a new orientation to point the Zarya Control Module toward deep space and the Unity Module toward the Earth. Commands were then sent to place the station into a slow spin of about one revolution every 30 minutes to keep the station within proper thermal conditions as it orbits the Earth. Zarya's motion control system will be reactivated about once a week over the next few months to insure it is working properly and its guidance system will be updated with the latest orbital parameters.
Before beginning their presleep period, the astronauts deployed a small 590-pound satellite called SAC-A for the Argentinean National Committee of Space Activities. Equipped with five technology experiments, including one to track the movement of whales off the coast of Argentina, SAC-A was ejected from a canister in Endeavour's cargo bay at 10:31 p.m. Central time as the shuttle few over the northern Indian Ocean. The satellite is expected to remain in orbit from five to nine months sending back data to Argentine researchers back on Earth.
The astronauts will begin an eight-hour sleep period at 3:36 a.m. Central time Monday and will be awakened at 11:36 a.m. to begin preparations for their scheduled landing at the Kennedy Space Center Tuesday night. On Monday, the astronauts will conduct the routine pre-landing check of Endeavour's flight control surfaces and steering jets to insure that the shuttle is ready for its high-speed reentry back to Earth.
Endeavour and the International Space Station are currently orbiting the Earth at an altitude of 246 statute miles with all of their systems operating normally.