Deployment of the port wing was delayed while ground controllers studied an apparent slackness in one of two blankets that make up the starboard structure. They believe that two tensioning cables had jumped off their guides during deployment. Despite that anomaly, the starboard array is functioning well and producing electricity. The slackness should have no effect on its ability to produce power for the space station.
Deployment of the second solar wing brings to 240 feet the span of the station's solar arrays. This array is 38 feet across and can produce as much as 60 kilowatts. It has a 15-year designed lifetime. It is the first of four such arrays that eventually will supply power to the station, enabling it to conduct basic and applied research in its microgravity environment.
The deployment was scheduled to begin with Endeavour and the space station in daylight and with television available so that array experts could watch the deployment from Mission Control. The port wing began to move from the two boxes that housed its two solar blankets and the mast canister between them that housed the lattice structure that pushed their ends outward, after a computer command by Endeavour commander Brent Jett. The deployment was slow, with stops and starts. It was completed, after two rows of solar panels stuck together were shaken lose by slightly retracting, then extending the arrays again, at 8:46 p.m.
Jett and the other four astronauts aboard, pilot Mike Bloomfield and mission specialists Joe Tanner, Carlos Noriega and Canadian Marc Garneau, had a relatively quiet day Monday. They conducted an extensive camera survey of the starboard array before deployment of its twin began. They also did housekeeping chores and monitored Endeavour systems before their scheduled sleep period beginning about 11 p.m.
Aboard the space station, the Expedition One crew, commander Bill Shepherd and cosmonauts Yuri Gidzenko and Sergei Krikalev, continued their work to outfit the ISS. After a wakeup tone at midnight - about the time the Endeavour crew went to bed -- the station crew installed a dust collector fan, collected condensate water samples, replaced a microprocessor and made observations of Patagonian glaciers. They will meet face-to-face with Endeavour crewmembers on Friday, after all three spacewalks by Tanner and Noriega have been completed.
The second of those spacewalks is scheduled for Tuesday. Its main purpose is to install data and power cables to allow the space station to use electricity generated by the new solar arrays.