NASA has announced new details on the Asteroid Redirect Mission (ARM), which over the next decade aims to test new technologies for use in future manned missions in deep space. However, this mission will be accomplished by a spacecraft that will reach an asteroid, will pick up a boulder and will carry it up to the Moon to place it in a stable orbit. There, astronauts will be able to go to study it to prepare for deep space missions.

For several years, NASA has been working on various projects related to the asteroids. The OSIRIS-REx mission aims to take samples of the asteroid 101955 Bennu to bring back to Earth. The most ambitious idea was to capture a whole asteroid to carry to the orbit of the Earth or the Moon. It was the most ambitious version of the ARM project.

Yesterday, Robert Lightfoot, NASA Associate Administrator, announced that the agency will develop the so-called option B, a less ambitious version of the ARM project. It consists in sending a robotic spacecraft to pick a boulder from an asteroid and carry it to the Moon’s orbit.

The spacecraft will be equipped with Solar Electric Propulsion (SEP), a type of ion propulsion that uses solar energy to be converted into electricity used to power the engine. The thrust is reduced compared to chemical rockets but requires much less fuel.

To accomplish its mission, the spacecraft will have to test new techniques of navigation in deep space near the moon. The asteroid to be reached will be selected during the last stage of preparation, in 2019. The candidates are Bennu, the target of the mission OSIRIS-REx, Itokawa, visited by the Japanese Hayabusa spacecraft in 2005, and another asteroid called simply 2008 EV5.

The robotic spacecraft is supposed to be launched in 2020. In addition to picking up a boulder, it has also a mission related to the possible Earth defense from asteroids, another part of NASA’s plans. Over the years, various possible ideas have been conceived to defend the planet from a possible impact and one of them is to divert asteroids using the force of gravity of a spacecraft.

The mass of a spacecraft robotics is relatively small, however it may be enough to divert another mass that is not particularly big either. The effect will be even greater after the spacecraft will have picked up a boulder from the asteroid. The data that will be collected on the interaction between the spacecraft and the asteroid will allow to understand if that’s a practical method to deflect a potential hazard when it’s still far from the Earth.

The boulder should be transported to the Moon’s orbit around the middle of next decade. At that point, the Orion spacecraft and its SLS (Space Launch System) should be ready for an exploration mission. A group of astronauts will reach the lunar orbit to study the boulder brought back by the robotic spacecraft testing technologies for human travel into deep space.

This mission is long-term so it might be modified in the next few years. In fact, it’s not yet certain that will be carried out because it’s one of the missions supported by President Barack Obama’s administration but the next president might have different ideas.