CAPE CANAVERAL, Fla. -- NASA has cleared space shuttle Endeavour for liftoff Sunday.

Mission managers gave the go-ahead Friday, as forecasters offered up an improved forecast. The chance of good launch weather is now 80 percent.
Endeavour is delivering a new room and observation deck to the International Space Station.

Shuttle managers acknowledged that many at NASA are still in shock over this week's space exploration shake-up. But they said the work force remains focused on a safe flight for Endeavour.

SLIDESHOW: Shuttle Endeavour's Storied Career

President Barack Obama ordered a new course for NASA, ditching a back-to-the-moon program sought in the administration of President George W. Bush. Instead, Obama is proposing more research that could have astronauts heading to the asteroids or Mars.