1235p 11/12 Update: Endeavour cleared for Friday launch

=================================

CBS NEWS STS-126 STATUS REPORT: 07
Posted: 12:35 PM, 11/12/08

By William Harwood
CBS News Space Analyst

Changes and additions:

   SR-04 (10/23/08): Endeavour hauled from pad 39B to 39A
   SR-05 (10/30/08): Endeavour cleared for 11/14 launch; Hubble mission delayed to at least May
   SR-06 (11/11/08): Shuttle countdown on tap; weather 60 percent 'go' for Friday launch
   SR-07 (11/12/08): Countdown underway; forecast still 60 percent 'go' for Friday launch

=================================

12:35 PM, 11/12/08, Update: Countdown underway; forecast still 60 percent 'go' for Friday launch

The shuttle Endeavour's countdown began on time Tuesday night and with no technical issues of any significance, NASA's Mission Management Team today cleared the spacecraft for launch Friday on a critical space station assembly and maintenance mission. Liftoff is targeted for 7:55:34 p.m. Friday and forecasters continue to predict a 60 percent chance of acceptable weather.

"At the end of the discussion we determined we don't have any open issues, no open work, no open constraints," said MMT Chairman LeRoy Cain. "So we're ready to go, the vehicle, the crew and the ground teams have prepared very hard for this mission. We were postured to fly a different mission just a month or so ago. But we were always planning on flying this mission this Fall, and so we're ready to go do that now."

He was referring to the planned mid-October launch of the shuttle Atlantis on a mission to service and upgrade the Hubble Space Telescope. Because of a component failure in orbit, that flight has been delayed to next May at the earliest to give engineers time to test and prepare replacement hardware.

Endeavour, which would have served as the emergency rescue vehicle for the Hubble crew, now is primed for launch Friday on the same mission it would have flown after a successful Hubble flight: A critical space station visit to install water recycling gear, a new toilet, a second galley and two of four crew sleep stations that will set the stage for expanding the lab crew from three to six next year.

Endeavour's crew also plans to carry out four spacewalks to attach equipment and spare parts to the station and to clean and lubricate a contaminated solar array rotary joint on the right side of the station. A similar joint on the left side of the station's main power truss is operating normally, but the astronauts will apply lubrication as preventive maintenance.

In addition, astronaut Sandra Magnus, hitching a ride to the station aboard Endeavour, will replace outgoing flight engineer Gregory Chamitoff, who was launched to the lab complex last June. Chamitoff will return to Earth aboard Endeavour.

Magnus, commander Chris Ferguson, pilot Eric Boe, Don Pettit and spacewalkers Heidemarie Stefanyshyn-Piper, Stephen Bowen and Robert "Shane" Kimbrough flew to me Kennedy Space Center from Houston Tuesday to make final preparations for launch.

"This mission is all about home improvement, home improvement both inside and outside the international space station," Ferguson told reporters. "On the inside of the space station, the walls are largely up. We've had some large modules delivered in the last year. Well, it's moving day, it's time to fill them up. And on the outside, on the outside we have some never-before-attempted repair work. That repair work will be to hopefully improve the performance of a faulty solar alpha joint rotation mechanism with grease. We've never tried anything like this. So on our first EVA out there on flight day number five, Heide and Steve will hit the bricks with grease guns, scrapers and new trundle bearings in an attempt to bring new life back to the solar alpha joint."

Launch director Mike Leinbach said today Endeavour is in good shape "and we're not tracking any issues that would prevent a launch at this stage."

The weather, of course, is another issue. Shuttle weather officer Kathy Winters said the forecast still calls for a 60 percent chance of acceptable weather based on computer models tracking a frontal system expected to reach central Florida on Saturday.

"What we're mainly concerned about with weather is a frontal boundary that's going to be moving into the area," she said. "And it's going to be affecting us more on Saturday, but there could be some pre-frontal weather, particularly our concern is showers in the area and also cumulus cloud development within 10 nautical miles of the launch pad."

Good weather is expected at emergency runways in New Mexico and California and in Moron, Spain. The forecast for Saturday calls for a 60 percent chance of bad weather, improving to 70 percent "go" after the front passes through.

Endeavour's launch window extends through Nov. 25. But it's not yet clear if the mission can be launched after Nov. 21. The Russians plan to launch an unmanned Progress supply ship Nov. 26 that will reach the station on Nov. 30. Flight controllers like at least a day of cushion between the departure of one vehicle and the arrival of another.

The Russians have agreed to delay the Progress docking, if necessary, to accommodate the shuttle. But as of this writing, the agreement only covers a delay of about a week. If Endeavour launched as late as Nov. 21, the shuttle would undock from the station on Dec. 5, the day before the Progress would have to dock under the current agreement. Based on that, Endeavour would have to be off the ground by Nov. 21 at the latest.

Leinbach said today he does not expect it to come to that.

"Our standard plan is to try four attempts in five days," he said. "Given that and barring any major facility or vehicle problems, we have a very high likelihood of launching, it's up in the 90 percent range, probably 93 to 95 percent."

But Cain said if the flight was delayed to the point where additional launch attempts after Nov. 21 might be needed, NASA would re-open talks with the Russians to explore additional options.

=================================

Quick-Launch Web Links:

CBS News STS-126 Status Reports:
http://www.cbsnews.com/network/news/space/current.html

CBS News STS-126 Quick-Look Page:
http://www.cbsnews.com/network/news/space/currentglance.html

NASA ISS Expeditions Page:
http://www.nasa.gov/mission_pages/station/expeditions/index.html

NASA Shuttle Web: http://spaceflight.nasa.gov/shuttle/index.html
NASA Station Web: http://spaceflight.nasa.gov/station/index.html
Spaceflight Now: http://spaceflightnow.com/index.html
GoogleSatTrack: http://www.lizard-tail.com/isana/tracking/

=================================