NASA hopes to launch an unmanned spacecraft that will use a robotic arm to collect samples from an asteroid by 2016 before sending a manned mission by the late 2020s.

A manned mission will aim to rendezvous with an asteroid up to three million miles from the Earth, taking around a year to make the entire round trip. The astronauts could stay on the asteroid for up to 30 days.

The officials will say that such missions to asteroids could help test technology for future human missions to other planets including Mars.

In the Hollywood movie Armageddon, a crew of astronauts and oil rig drillers are sent into space to land on a massive asteroid that is on a collision course with the Earth, where they drill beneath the surface to plant nuclear warheads in the hope of destroying it.

Six astronauts will next month be sent to an underwater base off the coast of Florida where they will spend 12 days living 65 feet beneath the surface of the Atlantic Ocean to simulate working in the difficult low gravity environment of an asteroid. They will share a 43 feet long by 20 feet wide underwater capsule where they will live, eat and sleep as part of the NASA Extreme Environment Mission Operation, or NEEMO.