NASA may be able to test Earth's defenses against space rocks during its mission to place an asteroid next to the moon.
The space agency announced last year that it plans to harness a near-Earth asteroid in a stable lunar orbit to be visited by astronauts for research and exploration, according to Discovery News.
NASA officials said they are working out the missions details, and that different methods could be used to deflect asteroids heading for Earth. In the case that the mission grabs a small space rock or a large boulder off an asteroid's surface, a planetary-defense demonstration will be involved, which will show the first test of an "enhanced gravity tractor" in space.
The gravity tractor technique uses a robotic probe flying next to a space rock for months, perhaps years, while a small gravitational tug gradually pushes it off course, Fox News reported.
If the probe has a larger mass, it will have a greater gravitational pull. Removing a boulder off an asteroid that could damage Earth will help greatly increase the mass of the deflection mission.
"We'd go into this enhanced gravity tractor position after we retrieve the boulder and demonstrate that we have even more gravity attraction capability by doing that," said Lindley Johnson, program executive for NASA's Near-Earth Object (NEO) observations program.
Johnson also said that almost a dozen candidates have been found for the mission, with at least six for each option. Itokawa, a 1,750-foot-long space rock visited by Japan's Hayabusa probe in 2005, could be the best rock to be used for the boulder-grab mission, Discovery News reported.
A 2025 exploration deadline has been set by the U.S. government to have astronauts visit the asteroid. President Barack Obama told NASA in 2010 to land astronauts on a nearby asteroid by 2025 as well as on Mars by the mid-2030s.
The agency is currently looking over data and ideas for the mission, putting it in a "preformulation" phase, Fox News reported.
Officials said NASA is looking to have a basic concept for the mission by the end of the year.
