The US space agency on Wednesday announced plans to send the first unmanned spacecraft to an asteroid to collect samples and return them to Earth for further study.

The spacecraft, known as Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer, or OSIRIS-REx, will launch in 2016 and will then travel four years before it nears its target.

The destination is a near Earth asteroid known as 1999 RQ36.

After six months of surveying the terrain from a distance of three miles (five kilometers), NASA scientists will choose a spot, activate the craft's robotic arm, and pluck about two ounces (57 grams) of material to return to Earth.

The samples are scheduled to arrive in 2023.

"This is a critical step in meeting the objectives outlined by President (Barack) Obama to extend our reach beyond low-Earth orbit and explore into deep space," said NASA Administrator Charlie Bolden in a statement.

"It's robotic missions like these that will pave the way for future human space missions to an asteroid and other deep space destinations."

Asteroids can offer clues about the birth of the solar system because they formed from the cloud of gas and dust known as the solar nebula some 4.5 billion years ago.