CAPE CANAVERAL, Fla. - Astronauts aboard NASA's shuttle Atlantis are hoping for clear skies over Florida tomorrow as they near the end of a successful construction flight to the International Space Station (ISS).
Shuttle commander Stephen Frick and his six crewmates are scheduled to land Wednesday at 9:07 a.m. EST (1407 GMT) here at NASA's Kennedy Space Center (KSC), though the space agency has also called up a backup runway at California's Edwards Air Force Base.
"We're certainly very hopeful that we'll be getting home tomorrow at the Kennedy Space Center," Frick told ABC News today. "It sounds like we'll be very likely to land at Kennedy or Edwards."
Frick and his crew are wrapping up a 13-day spaceflight that delivered the European Space Agency's (ESA) Columbus laboratory and a new crewmember to the space station. Atlantis undocked from the ISS early Monday after nine days working alongside the station's three-person crew to install and outfit the 10-ton Columbus during three spacewalks.
Current forecasts from the Spaceflight Meteorology Group at NASA's Johnson Space Center in Houston predict fair weather over the shuttle runway at KSC on Wednesday morning, with a slight chance of rain possible at Edwards later in the day.
"Atlantis and her crew are ready for reentry tomorrow," NASA flight director Bryan Lunney said in an afternoon briefing.
Lunney said Atlantis" heat shield has been given a clean bill of health based on the crew's Monday inspection of its wing edges and nose cap. The loss of four aft-mounted thrusters due to a heater glitch late yesterday will not affect Wednesday's landing, as they are not required for reentry, he added.
NASA traditionally targets its KSC runway for a returning shuttle's first day of landing opportunities to cut down on the extra time and costs involved in hauling an orbiter back to its Florida hangar. A California landing typically adds a week and $1.7 million to an orbiter's turnaround for its next flight, NASA officials have said.
But space agency officials decided last week to activate the Edwards landing strip in California's Mojave Desert to give Atlantis more chances to land and clear the way for the U.S. military to shoot down a defunct spy satellite. The U.S. Navy plans to launch a missile from an Aegis cruiser in the northern Pacific to destroy the failing reconnaissance satellite and prevent its half-ton load of toxic rocket fuel from endangering people on the ground.
Atlantis has two chances to land at KSC and two more to set down at Edwards, though Lunney said he plans to use only three of the available opportunities due to the shuttle's available water supply for cooling. But, he added, the space agency is under no pressure from the military to land Atlantis, even if weather does not cooperate.
"We're not going to land the vehicle until it is safe for our crew," he said.
Frick and shuttle pilot Alan Poindexter, both active U.S. Navy officers, had words of encouragement for their seafaring comrades hoping to smash the falling satellite after Atlantis lands.
"My first thought when we talk about that is 'Go Navy!'" said Frick, adding that debris from the satellite's destruction will be too low to pose a threat to the ISS. "We'll be interested to watch and see what happens."
Riding home aboard Atlantis is U.S. astronaut Dan Tani, who is returning to Earth after four months in orbit aboard the ISS. Tani's mother died in December after his mission was extended due to launch delays for Atlantis' current spaceflight. He said Wednesday that he believed he had worked through his grief and thanked family and flight controllers for their support.
"Like a lot of things, you just deal with what you're given," he told CNN. "My job had me on the space station and life happens. Great things and terrible things happen."
Atlantis' STS-122 mission is the first of up to six planned shuttle flights for NASA this year. In addition to delivering Europe's 1.4 billion euro ($2 billion) Columbus lab, shuttle astronauts also replaced an empty nitrogen tank and retrieved a broken gyroscope during their mission's spacewalks.
The shuttle astronauts have aimed video cameras at several radiator hoses to record how they retract tomorrow as Atlantis' cargo bay doors are closed, Lunney said, adding that the imagery will help engineers on Earth. One of the hoses had to be repositioned before the shuttle's Feb. 7 launch after it bent the wrong way.
Atlantis has enough supplies to stay aloft until Friday, but flight controllers typically keep one day in reserve for unexpected technical glitches. The STS-122 astronauts spent today converting their spacecraft for flight through Earth's atmosphere today, and are gearing up for their landing tomorrow, Lunney said.
"I think they're in great shape," he added. "They're well rested and ready to go land tomorrow."
NASA is broadcasting Atlantis' STS-122 mission live on NASA TV. Click here for SPACE.com's shuttle mission coverage and NASA TV feed.