The $800 million mission, which will call on a robot to collect pieces of the asteroid ( ), will be the first U.S. mission back to Earth.

Expected to launch in 2016, the spacecraft is scheduled to reach the asteroid -- dubbed 1999 RQ36 -- by 2020 and then return to Earth in 2023.

"This is a critical step in meeting the objectives outlined by President Obama to extend our reach beyond low-Earth orbit and explore ," said NASA Administrator Charlie Bolden, in a written statement. "It's like these that will pave the way for future human space missions to an asteroid and other deep space destinations."

NASA says the spacecraft, which was given the lengthy name of Origins-Spectral Interpretation-Resource Identification- -Regolith Explorer, will come within three miles of the asteroid and then hold that position for six months to map the object's surface. The asteroid is about the size of five football fields, NASA reports.

After that is accomplished, the spacecraft will move in to a distance of about six feet from the asteroid, Michael Drake, principle investigator on the mission, told Computerworld. The spacecraft's robotic arm will then deploy, reaching out to first blast the asteroid surface with nitrogen gas so a device, which resembles a car air filter, on the end of the arm can scoop up more than 2 ounces of the loosened material.