Engineers at the Kennedy Space Center are readying the shuttle Endeavour for launch Nov. 10 or 11 on a mission to deliver a fresh three-man crew and a 14.5-ton solar array truss segment to the international space station.

Endeavour rolls to launch pad 39A for the upcoming mission to deliver P1 to the space station. Photo: NASA

Launch is tentatively targeted for between 12 a.m. and 4 a.m. EST Nov. 10, but the flight could slip a day to give the space station's crew - Expedition 5 commander Valery Korzun, Sergei Treschev and Peggy Whitson - a bit more time between the departure of a Soyuz taxi crew and the arrival of Endeavour.

The three-man taxi crew is scheduled for launch from the Baikonur Cosmodrome at 10:11 p.m. EST on Oct. 29. Docking is targeted for around midnight Nov. 1. Commander Sergei Zalyotin, Yuri Lonchakov and Belgian flier Frank DeWinne are delivering a fresh Soyuz lifeboat to replace the one currently docked to the Zarya module's downward facing port. Soyuz spacecraft, which a station crew could use in an emergency to bail out and return to Earth, must be replaced every six months.

The Soyuz "taxi" crew originally was scheduled for launch Oct. 27 (eastern time), but the flight was delayed following the explosion last week of an unmanned Soyuz booster. In addition, the planned reboost of the station by an unmanned Progress supply ship, needed to synchronize the lab's orbit for the Soyuz rendezvous, came up a bit short. That alone prevented an on-time launch for Zalyotin's crew barring an additional reboost session.

Flight Engineer Yuri Lonchakov, commander Sergei Zalyotin and Belgian astronaut Frank DeWinne. Photo: RGNIITsPK

Given the current launch date, the taxi crew will undock from the space station around 3:30 p.m. on Nov. 9 for a landing around 7 p.m. EST that evening. Assuming NASA sticks with Endeavour's Nov. 10 launch target, the shuttle's crew would head for the pad to strap in the already fueled orbiter within a few hours of the Soyuz landing.

Again, assuming a Nov. 10 launch, shuttle commander James Wetherbee will guide Endeavour to a docking with the space station late in the evening of Nov. 11. The next day, the P1 solar array truss segment mounted in the shuttle's cargo bay will be picked up by Endeavour's robot arm and then handed off to the station's Canadarm2 space crane for installation on the left, or port, side of the central S0 truss.

The station's solar array truss eventually will consist of 11 segments. The first segment, S0, was attached to the upper hull of the Destiny laboratory module in April. The first right-side, or starboard, segment - S1 - was installed earlier this month. The attachment of P1 on the port side will extend the backbone to three segments.

Backdropped by a blanket of clouds, the space station as seen by the departing shuttle Atlantis with the S1 truss extending to the left. Photo: NASA

S1 and P1 contain the station's primary ammonia cooling system, including pumps piping and six huge radiator panels, three per truss segment. Heat generated by the station's electrical systems will be transferred from internal water loops to external ammonia lines in heat exchangers and then routed outboard to the S1/P1 radiator panels.

Astronauts Michael Lopez-Alegria and John Herrington plan to stage three spacewalks to connect electrical cables, data lines and ammonia fluid jumpers between P1 and S0. They also will install a second CETA cart, a sort of astronaut rail car that will help future spacewalkers move along the truss.

The second primary goal of the 112th shuttle mission is to ferry the station's next full-time crew to the lab complex - Expedition 6 commander Kenneth Bowersox, flight engineer Nikolai Budarin and science officer Donald Pettit. Pettit was added to the crew this summer after the original ISS-6 science officer, Donald Thomas, was unexpectedly removed because of an undisclosed medical issue.

The ISS-5 expedition was launched to the station June 5. Assuming Endeavour launches Nov. 10, Korzun, Treschev and Whitson will have logged 168 days in space when they land Nov. 21. Bowersox and his crew plan to remain aboard the station until mid to late March.