NASA managers completed a two-day flight readiness review today and formally cleared the shuttle Endeavour for blastoff March 11 on a 16-day space station assembly mission featuring five spacewalks, delivery of a new Japanese module and assembly of a complex Canadian hand-like attachment for the station's robot arm.

Endeavour's seven-member crew - commander Dominic Gorie, pilot Gregory Johnson, flight engineer Michael Foreman, Richard Linnehan, Robert Behnken, Japanese astronaut Takao Doi and space station flight engineer Garrett Reisman - plans to fly to the Kennedy Space Center next Friday night for the 3 a.m. Saturday (March 8) start of the countdown to launch.

Liftoff is targeted for 2:28:10 a.m. on March 11, roughly the moment Earth's rotation carries launch complex 39A into the plane of the space station's orbit.

"We had a very thorough review over the last day and a half," said Bill Gerstenmaier, manager of space operations at NASA headquarters. "The teams are ready to go launch here on March 11. We're really not working very many open items, and that's a tribute to the team and the great performance of Atlantis (on the recently concluded STS-122 mission).

"There wasn't a lot of work that we're carrying forward out of this review into the next review at L-minus 2 (days) and that's a tribute to the team and it's also evidence that we're really ready to go fly and we're not rushing things."

Gerstenmaier said analysis of debris from a disabled spy satellite that was blown apart by a Navy missile last week in a dramatic shoot down showed no significant additional risk for Endeavour's crew.

"We took a look at that, we had our analysts take a look at the latest predictions of what debris is remaining from that event, we've calculated it and it really poses no risk to the shuttle with where we are. There's just a small change in risk over the mission, I think we went from 1-in-269 to 1-in-259, which is just a minor, trivial change. We probably don't know the debris model that well to see that kind of difference. So we looked at it, we reviewed it, we'll continue to talk to folks to make sure there's nothing, but we don't see any concerns."

The numbers, he said, refer to the odds of a "critical penetration" of the shuttle by space debris over the course of the 16-day mission.

NASA will have two days to get Endeavour off the ground before standing down to make way for the launch of an Air Force Delta 2 rocket carrying a new Global Positioning System navigation satellite. Launch is scheduled for March 15 at 2:09 a.m.

"In order to turn around the range from our launch attempts to theirs requires 48 hours," said shuttle Launch Director Mike Leinbach. "So we have two launch attempts for the shuttle program, the 11th and 12th. If we don't launch by the 12th we have to stand down for the Delta program. And that's about a five-day stand down when you add all the factors together. Our next launch attempt would be the 17th."

Assuming an on-time launch, Endeavour will dock with the space station around 11:27 p.m. on March 12. The Japanese logistics module will be installed the next day during the first of five planned spacewalks. Linnehan and Reisman will carry out the first excursion, Linnehan will be joined by Foreman for the second on March 15 and by Behnken for the third on March 17. All three will be devoted primarily to assembling the new Canadian special purpose dexterous manipulator, or DEXTRE, a mechanical hand of sorts that can be attached to the station's robot arm.

Benkhen and Foreman will carry out the final two spacewalks on March 20 and 22 to test a heat shield repair tool and to help mount the shuttle's heat shield inspection boom on the station. The 50-foot-long boom will be left behind when Endeavour departs because of interference issues when a second, much larger Japanese module is launched on the next assembly mission in late May.

If all goes well, Endeavour will undock from the space station around 8 p.m. on March 24 and land back at the Kennedy Space Center around 8:35 p.m. on March 26.

Endeavour's flight is the longest yet for a shuttle visiting the international space station. The long duration is possible because of a new station-to-shuttle power transfer system that will let Endeavour tap into the lab's solar power grid.

New shuttle Program Manager John Shannon said there are no plans at present to extend Endeavour's mission beyond 16 days, although that option is available if problems develop or if the crew needs additional time to accomplish major mission objectives.

"Right now, we have 16 days, we have one extension day that we could add to the flight," Shannon said. "Right now, the entire mission fits inside those 16 days. But it is very complicated, it's a very complex mission, we're doing a lot of different things. So I wouldn't say absolutely we won't extend or not. We have that option available to us."

Adding to the complexity of the operation, the European Space Agency is scheduled to launch the "Jules Verne," its new Automated Transfer Vehicle, or ATV, next Friday night from Kourou, French Guiana. The ATV, a large, unmanned cargo carrier designed to ferry critical supplies and equipment to the space station, is scheduled to dock at the aft port of the station's Russian Zvezda module at 10:20 a.m. on April 3. It will be "parked" in orbit some some 1,200 miles from the station during Endeavour's mission.

Because the shuttle, station and ATV all rely on NASA communications satellites, "there will be some times during the mission where we may not have comm with the orbiter like we normally do," Gerstenmaier said. "We'll have comm periodically during an orbit, not all the time. So we discussed that (today). if we really need comm with all three vehicles - ATV, shuttle and station - we can do that, we can set it up. But from a scheduling standpoint, we'd like to minimize those periods where we need high-rate communications with all three vehicles."

Additional coverage for subscribers:
VIDEO: FLIGHT READINESS REVIEW NEWS BRIEFING PLAY
VIDEO: TCDT TRAINING HIGHLIGHTS PLAY
VIDEO: PRESS CHAT WITH CREW AT LAUNCH PAD PLAY
VIDEO: CREW ARRIVES AT KSC FOR PRACTICE COUNT PLAY
MORE: STS-123 VIDEO COVERAGE
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