Following undocking, Atlantis will back away from the ISS to a distance of about 450 feet before completing at least a half lap fly around of the complex with its new truss segment installed before departing the station's vicinity at 10 a.m. and prepare to come home to the Kennedy Space Center in Florida at 10:45 Friday morning. Expedition Five's ride home is next month aboard Endeavour following its mission to deliver a mirror image truss segment to the S1.
Atlantis departs after delivering about 1,800 pounds of supplies and experiments to the station and returning about the same weight of cargo to Earth. It also leaves behind the S1 (Starboard One) Truss segment weighing almost 15 tons and spanning 45 feet. It continues the outward expansion of the truss that eventually will be 356 feet long.
The work to install the S1 was accomplished during three spacewalks totaling more than 19 hours that included hooking up power, data and ammonia lines linking S1 to the station; deploying antennas, installing TV cameras, preparing a handcar for use on the truss' railway, readying S1's three large radiators for use and installing devices to ensure quick disconnect fittings in fluid lines will work.
Later this morning, the shuttle performs its own experiment when SHIMMER is activated to measure Hydroxyl in the upper atmosphere. Hydroxyl plays a role in the ozone destroying chemical process and helps in measuring water vapor and temperature over a broad altitude range.
The day began for the shuttle and station crews with a wakeup call from Mission Control at 2:52 a.m. The Alan Parsons Project's "Prime Time" was played for Pilot Pam Melroy, requested by her husband, Chris.