By Marcia Dunn

Cape Canaveral, Florida - Nasa's newest rocket is on the verge of blasting off on a test flight.

The Ares I-X rocket is set to lift off on Tuesday morning. But forecasters say there's a 60 percent chance that rain and clouds could delay the experimental flight.

It's the first step in Nasa's effort to return astronauts to the moon.

The flight will last two minutes and cost $445-million (about R3-billion). Parachutes will drop the first-stage booster into the Atlantic for recovery. The upper portion of the rocket - all fake parts - will fall uncontrolled into the ocean.

No matter what happens, Nasa managers say they expect to learn a lot from the flight, even if it's for another type of rocket. The White House is re-evaluating the entire human spaceflight program. - Sapa-AP