CAPE CANAVERAL – Astronauts aboard the shuttle Atlantis are preparing to re-enter the atmosphere and return to Florida, wrapping up a 13-day mission to the International Space Station.

If NASA commits the craft to its “de-orbit burn” just before 8 a.m., the astronauts will be on target for a planned 9:07 a.m. landing at Kennedy Space Center.

There are concerns about scattered clouds and strong upper-level winds, but NASA hopes to bring the astronauts home on the first attempt.

If weather doesn’t cooperate, the crew will try again 90 minutes later, or look at landing at Edwards Air Force Base in California.