Live At KSC: Shuttle Heads For 2nd Landing Attempt

LIVE IMAGES: The image above is the latest live image from NASA Television. It will automatically refresh itself to the most up to date image every 30 seconds.

The Atlantis astronauts will try to land at Kennedy Space Center again today, but storms could divert them to California or keep them in orbit another day.

Atlantis is slated to land at KSC at 9:15 a.m. EDT.

Two other opportunities are available: 10:54 a.m. and 12:32 p.m. But NASA likely would opt to forego the third opportunity. It would make for an extremely long day for the astronauts, who face several hours of post-flight medical exams.

Thunderstorms, lightning and rain showers are expected within 30 miles of the shuttle runway again today - conditions similar to those that forced NASA on Friday to wave off two landing chances at KSC. Low cloud ceilings also are a possibility.

The outlook prompted NASA to call up Edwards Air Force Base as a back-up. Conditions there are expected to be near-pristine for landing opportunities at 10:44 a.m. and 12:23 p.m. and 2:02 p.m. EDT.

A good forecast for KSC on Sunday might prompt NASA to keep Atlantis in orbit another day. It costs $1.8 million to ferry an orbiter back to Florida from California.

Atlantis has enough electrical power to remain in orbit until Monday.

As it stands, the Atlantis crew will step into their deorbit preparations at about 4 a.m. and the shuttle's payload bay doors are to be closed for flight at 5:21 a.m.

A go/no-go decision around 5 a.m. will be indicative of whether mission managers think conditions might be acceptable for landing on the first KSC opportunity.

The astronauts are slated to begin donning their partial pressure launch-and-entry suits at 6:36 a.m., and mission managers would make a go/no-go decision on a deorbit burn at 7:41 a.m.

If all goes well, the astronauts would fire the shuttle's twin orbital maneuvering engines at 8:01 a.m. The two-minute, 34-second burn would send the ship on an hour-long atmospheric reentry that would begin over the Indian Ocean -- almost 5,000 miles away from KSC.

The Atlantis astronauts would enter the area around KSC at 9:11 a.m. Flying at an altitude of 42,000 feet, mission commander Scott Altman would guide the shuttle on a sweeping 298-degree left hand turn out over the Atlantic Ocean before making a diving final approach to Runway 15 -- the northern end of the three-mile shuttle landing strip.

Touchdown would come at 15 seconds after 9:15 a.m.