NASA is studying how to launch a rocket to an asteroid, take a rock and carry it to the Moon, within the next five years, all to practice for a mission to Mars.

On March 25th, the space agency presented the details of the plan with an estimated cost of $ 1.25 billion in order to launch an unmanned spacecraft with solar energy and ion engine to the asteroid by December 2020. The probe should spend a year going around the big space rock, gathering a mass of 13 meters in diameter with a robotic arm.

This boulder would then be transported to the Moon and parked in the orbit. An Orion spacecraft would then get close to it so that two astronauts can reach it with a spacewalk in order to explore, take a piece and bring it back to Earth.

The mission would serve to "demonstrate the capabilities that we need for future human missions beyond Earth's orbit and then ultimately to Mars" as stated by Robert Lightfoot, associate administrator of NASA.

The main target would be well identified: it is a rock of about 450 meters in diameter that was discovered in 2008 and named EV5, one of the largest asteroids around the sun and close enough to the Earth. However, there would be two other, called Itokawa and Bennu, discovered by Japanese probe Hayabusa.

NASA has chosen this option instead of a giant asteroid chosen last year as this would have taken a long time grab and pull back to Earth. With this new choice, while costing about $100 million dollars more, NASA can develop technologies suitable for the human space exploration. The price of $ 1.25 billion does not include the cost of rockets and spaceships.

The entire project called ARM (Redirect Asteroid Mission) will test the new space suits, developed for the deep space, very different from those used for spacewalks in Earth orbit and more advanced than those used to walk on the moon 45 years ago.

NASA spokesman David Steitz added that similar missions will also be useful in terms of "planetary defense", in the event that an asteroid coming too close to our planet.