Updated

CAPE CANAVERAL, Fla. – The weather is looking good for NASA's planned final liftoff of the space shuttle Atlantis Friday.

Mostly clear skies should greet the seaside launch pad here at Kennedy Space Center for the scheduled 2:20 p.m. EDT (1820 GMT) liftoff. The mission is expected to be the last for Atlantis and one of three final shuttle flights before NASA retires its three-orbiter fleet later this year.

Ground crews plan to begin loading Atlantis' giant orange external fuel tank with its super-chilled liquid hydrogen and liquid oxygen propellants Friday at 4:55 a.m. EDT (0855 GMT).

"Good news as far as the weather is concerned," said STS-132 weather officer Todd McNamara during a Thursday briefing. "Overall we're looking at really good conditions for launch operations."

McNamara predicted a 70 percent probability of favorable weather for the launch, with a small chance of low cloud ceilings preventing the shuttle from taking off. NASA needs cloudless skies so that range safety officials have a clear view to watch the entire launch.

Atlantis is slated to carry six astronauts and a new Russian research room called the Mini Research Module-1 (MRM-1) to the International Space Station. The flight will also deliver a host of supplies and spare parts to help outfit the station for the era after NASA's three-orbiter space shuttle fleet retires, planned for the end of the year.