Live at KSC: NASA Steps Up Launch Preps

NASA is finishing up a critical effort to service shuttle Endeavour's three power-producing fuel cells this morning as the agency enters the final full day of the countdown to a planned Friday night launch from Kennedy Space Center.

A team of NASA and contractor engineers in Firing Room 4 of the Launch Control Center started loading liquid hydrogen and liquid oxygen into the shuttle's Power Reactant Storage Distribution system about 6 p.m. Wednesday.

The so-called PRSD load is scheduled to wrap up early this morning and then launch pad 39A -- which remains closed to all but essential personnel during the hazardous operation -- will reopen for other launch preparations.

The shuttle's fuel cells combine liquid hydrogen and liquid oxygen to produce the electricity used to run all spaceship systems. Potable water is a byproduct that typically is bagged and hauled over to the International Space Station during shuttle visits to the outpost.

NASA will brief reporters on the fuel cell servicing and other work at a 10 a.m. news conference that will be webcast live here in The Flame Trench. Simply click the NASA TV box on the righthand side of this page to launch our NASA TV viewer and live coverage of the L-1 Countdown Status Briefing.

NASA Test Director Charlie Blackwell-Thomas will cover work completed overnight as well as plans to roll back the Rotating Service Structure at the pad 39A around 11:30 p.m. tonight. NASA Payload Manager Joe Delai and Air Force shuttle weather officer Kathy Winters also will be on hand to provide the latest news.

Looking ahead, NASA's Mission Management Team will tag up at 10 a.m. Friday to decide whether to proceed with external tank propellant-loading operations at 10:30 a.m. that day.

Liftoff remains scheduled for 7:55 p.m. EST Friday -- the middle of a 10-minute launch window. The launch is precisely timed to put the shuttle on course for a Sunday evening docking at the space station.

Seven astronauts flying aboard Endeavour aim to outfit the international outpost for crews of six -- double the current size of resident crews.

They also will attempt to repair a 10-foot-diameter rotary joint designed to turn the station's starboard solar wing like a paddlewheel so it can constantly track the sun as the station circles Earth. The fouled-up mechanism has not been working properly since the autumn of 2007.

A NASA Mission Summary is here: STS-126 Fact Sheet

A more in-depth look at the mission is in the official NASA STS-126 Press Kit: STS-126 Press Kit

Mission commander Chris Ferguson and pilot Eric Boe practiced landings Wednesday evening in a Gulfstream II aircraft modified to mimic the shuttle's steep plunge toward the runway.

Nice NASA shot by ace photographer Kim Shiflett. You can click the image to enlarge and save it. It shows Ferguson easing the STA toward the runway as the aircraft is backlit by powerful xenon floodlights at NASA's Shuttle Landing Facility.

ABOUT THE TOP IMAGES: Refresh this page to get the latest still image from live video feeds at Kennedy Space Center. The top left image shows the Rotating Service Structure wrapped around shuttle Endeavour at launch pad 39A. It will be backed away from the vehicle about 11:30 p.m. tonight. The top right image shows the pad as seen from the roof of the Operations and Checkout Building in the KSC Industrial Area.