Each astronaut performed one gentle 50-foot flight with the nitrogen powered SAFER (for Simplified Aid for EVA Rescue). Each remained attached to the shuttle with a long tether during the test, and was accompanied by the other astronaut, moving with him on the end of Discovery's robotic arm.
This was the last of four successful spacewalks over four days that prepared the International Space Station for the arrival of its first crew next month. It also paved the way for future station expansion. The Wednesday spacewalk began at 10 a.m. CDT and ended at 4:56 p.m., lasting 6 hours and 56 minutes. It brings the total spacewalk time for the STS-92 mission to 27 hours and 19 minutes, and for all 10 space station assembly spacewalks on five shuttle missions to 69 hours and 34 minutes.
Lopez-Alegria and Wisoff, with Koichi Wakata operating the arm, completed a series of wrap-up tasks during the EVA. They removed a grapple fixture from the Z1 truss, opened and closed a latch assembly that will hold the solar array truss when it arrives in December, deployed a tray that will be used to provide power to the U.S. Laboratory Destiny, scheduled to be attached to the station early next year, and tested the manual berthing mechanism latches that will support Destiny.
Wisoff opened and closed the latches on the capture assembly for the P6 solar arrays using a pistol grip tool. With it he made more than 125 turns to open the latches, then closed and reopened them. He left the capture latch, called "the claw," ready to receive the solar arrays, to be installed by the STS-97 crew in December.
An exercise to test techniques for returning an incapacitated astronaut to the air lock was cancelled because of time constraints.
After the space walk, Commander Brian Duffy and Pilot Pam Melroy completed their third and final reboost of the space station, firing Discovery's reaction control system jets in a series of 18 pulses over a 30-minute period to gently raise the station's orbit to prepare it for the arrival of the first resident crew in early November. This reboost added another 1.7 statute miles to the station's average altitude, making the total for the mission just over 5 miles.