Friday, July 31, 2009

Live At KSC: Astronauts Aim For Homecoming

Seven astronauts aim to fly shuttle Endeavour on a supersonic slide back through the atmosphere today, capping a highly successful mission to complete construction of the Japanese Kibo science research facility at the International Space Station.

With the shuttle flying with its engines in the direction of travel, Endeavour mission commander Mark Polansky is scheduled to fire the ship's twin maneuvering engines at 9:42 a.m.

The three-minute, four-second firing on the shuttle's 248th orbit of Earth will slow Endeavour by 218 miles per hour -- or just enough to put the orbiter on an hour-long plunge back through the atmosphere.

Landing at Kennedy Space Center's shuttle runway is set for 10:48 a.m. -- 15 days, 16 hours and 45 minutes after its July 5 launch from pad 39A just fives miles away.

You can watch live coverage of the mission right now by clicking on the NASA TV box on the right hand side of the page. Doing so will launch our NASA TV viewer. Be sure to refresh this page for periodic updates.

You can also sign up to get text message alerts on the righthand rail of the page.

The weather forecast for landing is generally favorable. But this is summertime in central Florida, and there's a chance that a sea breeze could push in off the Atlantic, seeding rain showers and thunderstorms within 30 nautical miles of the KSC landing strip.

Rain showers or thunderstorms in the area would prompted NASA to keep Endeavour and its crew in orbit an extra 90 minutes -- if not an extra day. If the weather didn't clear in time for a landing on Orbit 249, then the shuttle crew would be granted a "bonus day" in space and we'd be back again for another landing attempt on Saturday.

As it stands, here is the crew's plan for today:

The astronauts will begin their deorbit preparation timeline before sunrise and then stow shuttle radiators that have been shedding heat from the ship since launch more than two weeks ago.

If all is going well, NASA mission managers should give the crew a go to close the shuttle's payload bay doors around 6:45. The 60-foot-long doors then would swing shut around 7 a.m.

Flight directors in NASA's Mission Control Center would give a green light to transitioning to atmospheric reentry and landing software around 7:12 a.m., and that action would take place 10 minutes later.

The astronauts would don partial-pressure launch-and-entry suits around 8:17 a.m., and the shuttle's toilet would be deactivated just after 9 a.m.

A go/no-go decision on deorbit burn would come about 9:22 a.m.

The Endeavour astronauts would have one additional chance to land at KSC today. It would come at 12:22 p.m.

The weather is expected to degrade as the day wears on so the first opportunity appears to be the best opportunity to bring the crew back home.

ABOUT THE IMAGES: Click to enlarge the long-range, mid-range, close-range ground tracks that depict the flight path shuttle Endeavour will take if it reenters the atmosphere on the first opportunity today, which would come on Orbit 248 of a 16-day flight to the International Space Station.


Spacefreak said...

So excited! I am in town for the first time for a landing. I know I won't be able to see anything, but I will get to hear it come home!

Eggy409 said...

and the shuttle's toilet would be deactivated just after 9 a.m.

"If you have to go, go now!"