US space agency NASA is planning to launch a robotic spacecraft to pick up a boulder about 10 feet in diameter from the surface of an asteroid and relocate it into an orbit around the Moon.
The mission was one of two under consideration by NASA to develop technologies and equipment needed to one day send astronauts to Mars.
The other option was to capture a small asteroid in a bag-like contraption and transport the whole body into a lunar orbit.
NASA will not decide its asteroid target until about a year before the robotic Asteroid Redirect Mission, or ARM, is launched, sometime around December 2020, NASA associate administrator Robert Lightfoot said.
The spacecraft would take about two years to reach its target. Upon arrival, the probe would take about a year, possibly longer, to conduct a detailed survey.
In addition to identifying potential boulders for relocation, a series of experiments is planned to test techniques to move the asteroid, technologies that may be useful one day if an asteroid was discovered to be on a collision course with Earth.
Once a target rock is selected, the capture probe would lower itself to the surface of the asteroid and deploy a pair of robot arms to grasp the candidate boulder, 'Discovery News' reported.
Springing off the surface with the boulder in hand, the mothership would position itself to be captured by the lunar gravity, a process estimated to take about six years.
By 2025, the Moon would have a new satellite in orbit.
Two NASA astronauts will then journey out to meet the robotic spacecraft and the boulder, using the agency's Orion capsule and Space Launch System megarocket, both of which are in development.
