CAPE CANAVERAL (AP): The US space agency has cleared shuttle Endeavour for liftoff on Sunday and says the launch team is keeping its focus on safety even though workers are facing uncertainty over the direction of the space programme.

Mission managers gave the launch go-ahead Saturday, as forecasters offered up an improved forecast. The chance of good launch weather is now 80 percent for the liftoff, set for 0939 GMT.

NASA managers cleared the space shuttle for liftoff even as they used words like “angst” to describe the mood of the work force at the launching site, days after the administration of US President Barack Obama announced changes in NASA's goals.

“Distractions are there. Shock is there. Uncertainty. But ... I do not worry about the folks’ while they're doing their job,” launch director Mike Leinbach said.

On Monday, Obama ordered a new course for the National Aeronautics and Space Administration, ditching the back-to-the-moon programme of the previous administration of President George W. Bush.

Instead, Obama is proposing more research that could have astronauts heading to the asteroids or Mars, sooner and cheaper than under the old plan. That's good news for the future of the International Space Station, which won an extension until 2020. But it could mean even more layoffs for the shuttle work force.