Shuttle Astronauts Prepare for Wednesday Landing

Astronauts Scan Space Shuttle's Heat Shield
The International Space Station as seen from space shuttle Discovery after undocking on Nov. 5, 2007 during the STS-120 mission.
(Image: © NASA TV.)

CAPE CANVERAL - After spending more than twoweeks in space, seven astronauts on board the space shuttle Discovery aremaking final preparations to return home tomorrow.

Beforetheir Wednesday arrival here at Kennedy Space Center (KSC), however, the crewwill check flight control systems, test engines and stow gear floating aroundthe cabin.

"It'smainly a day dedicated to preparations for deorbit and entry," said RickLaBrode, lead shuttleflight director, of today's activities.

The STS-120 missionlaunched Oct. 23 and hauled a bus-sized module to the International SpaceStation (ISS), which the crew said goodbye to Sunday and undockedfrom on Monday morning. LaBrode said computer problems on Discovery made forsome tricky navigation for its pilot George Zamka, but noted that he and therest of the crew persevered.

"Hedid an exceptionally good job," LaBrode said of Zamka's 360-degreefly-around of the space station yesterday. "It was prettyphenomenal."

NASA'sspace station construction mission also left behind astronaut Dan Tani,swapping his place with ISS crewmember Clay Anderson.

"Aboutfive months ago I was lying on back mid deck of the orbiter Atlantis andwondering what the heck I had gotten myself into," Anderson said duringSunday's tearfulgoodbye ceremony at the orbital laboratory. "Now I'm poised to returnto Earth."

Finalpreparations

Today's pre-landingactivities include interviews with SPACE.com and other members of thepress that will air live at 9:43 a.m. EST (1443 GMT), as well the set up aspecial recumbent seat for Anderson. The seat will ease Anderson--who has spent152 days in space--back into Earth's gravitational pull by laying him on hisback.

Discovery'screw will also test the spacecraft's on-orbit engines that blastcourse-correcting and deorbiting propellant.

In additionto the engine tests, LaBrode noted astronauts will test the spacecraft'ssensitive flight control systems before the crews fire an orbit-adjusting burnaround 2:54 p.m. EST (1954 GMT) and get a good night's rest at 6:38 p.m. EST(2338 GMT).

NASAengineers are also slated to deliver inspection results today of Discovery'sheat-resistant wing leading edges today, which mission managers said yesterdayshould pose any problems.

"There[are] no concerns expected at all," LaBrode said of the reinforced carbonshielding analysis.

These zonesof heat-resistant tiles bear the brunt of reentry to Earth, converting most ofDiscovery's 17,500 mph (21,160 kph) of speed into hot plasma--and heating the thermalshielding to as much as 2,300 degrees F (1,260 C).

Eventfulmission

The STS-120 mission brought a 15.75-ton, bus-sized room to the space stationand relocated a massive solar array truss segment. Deployment snagged and toreof one of the solar power tower's blankets on Oct. 30, however, pulling thecrew together to effect anunprecedented repair of the solar wing.

"It'sbeen an incredible mission and one that I will reflect ? on favorably for therest of my career," LaBrode said of his directing role.

Discoverywill make a daylight descent from the northwestern U.S. to Florida on Nov. 7,crossing over the "heartland of America," mission managers have said. This descent path has not been attempted since the loss of the crew of Columbia in 2003.

The spacecraft is scheduled to fire a speed-dropping deorbit burn at 12:03 p.m.EST (1703 GMT) for a 1:02 p.m. EST (1802 GMT) landing, weather permitting. Successfultouch down of will be followed by news and astronaut crew conferences about two hours and 6.5 hours aftwerward, respectively.

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