NASA under "no pressure" to land

The Atlantis astronauts aim to make a supersonic slide back through the atmosphere Wednesday, clearing the way for the U.S. Navy to shoot down a crippled U.S. spy satellite that otherwise could plunge to Earth with a tank full of toxic fuel.

Runways on both coasts will be open for Atlantis, but NASA and the astronauts will try to land the shuttle at 9:07 a.m. at Kennedy Space Center.

The Navy is facing a relatively short window to obliterate the failed National Reconnaissance Office spacecraft before it would make an uncontrolled reentry in early March, potentially exposing people on the ground to deadly rocket fuel.

NASA officials nonetheless say they would not hesitate to put off the shuttle's return to Earth if bad weather or unexpected technical problems were to crop up.

"No pressure. I'm not going to land the vehicle until it is safe to do so for the crew. And we're not going to alter any of our rules because it's not safe to do," NASA lead flight director Bryan Lunney, son of legendary Apollo flight director Glynn Lunney, told reporters today. "So if the weather is good on Wednesday, then we'll land on Wednesday. If not, then I'll push to Thursday."

The weather forecast for landing calls for near pristine conditions. Clear skies and light winds are expected. A cold front moved through central Florida early today with surface high pressure building in north Florida. The prime concern for landing Wednesday is a chance of low clouds or patchy fog forming near the coast at sunrise. But if that's the case, the fog likely would lift as surface heating and winds increased by mid-morning.

"We will see how the weather plays out. I'm real optimistic...that things are going to play out really well for Kennedy Space Center to land there on the first try," Lunney said. "Conditions are really, really good for us for coming in for a landing."

The Atlantis astronauts would have a second opportunity to land at KSC at 10:42 a.m., and there also would be two opportunities to bring the shuttle back to Edwards Air Force Base in California. Those would come at 12:12 p.m. and 1:47 p.m. EST.

The crew will begin deorbit preparations just after 4 a.m. and then close the shuttle's payload bay doors around 5:19 a.m. The astronauts will video a radiator hose that bent before launch, but no significant trouble is expected with it. The astronauts will start donning partial-pressure launch-and-entry suits around 6:34 a.m., and a go/no-go decision for the deorbit burn is expected around 7:48 a.m.

If all goes well, the shuttle's twin maneuvering engines would be fired just seconds before 8 a.m., sending Atlantis and its astronauts on a hour-long free-fall toward the three-mile runway at KSC.

Take a look at the crew's detailed entry checklist here: EntryCheckList.pdf.

And the crew's detailed timeline and landing plan is here: Entry_PAO_Execute_Package.pdf.

You can watch the action unfold right here in The Flame Trench. Simply click the link below the images above to launch our NASA TV viewer and round-the-clock coverage of STS-122.