NASA's OSIRIS-REx spacecraft is on its way to asteroid Bennu to perform a comprehensive surface mapping of the asteroid and to collect samples from the space rock using its robotic arm. Aside from that, the spacecraft is will also start to hunt for "Trojan" asteroids in space. What exactly are they?

Scientists are looking forward to NASA's Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) mission as it is the first ever project dedicated to retrieving and delivering asteroid samples to Earth. But that's not all the spacecraft can do. Reports say it will begin to hunt "Trojan" asteroids or the elusive space rocks that serve as a constant companion to planets within the Solar System. These elusive "Trojan" asteroids orbit that Sun together with the planet. They remain in a constant 60-degrees position either in the rear or front of the planet.

OSIRIS-REx will begin the search for the elusive asteroids in February next year and will spend roughly 12 days scanning for "Trojan" space rocks, according to Phys.Org. The elusive asteroids are considered interesting because, like satellites, they remain in their orbit without any chance of colliding with its host planet.

"The Earth-Trojan asteroid search provides a substantial advantage to the OSIRIS-REx mission," OSIRIS-REx Principal Investigator Dante Lauretta said in a statement. "Not only do we have the opportunity to discover new members of an asteroid class, but more importantly, we are practicing critical mission operations in advance of our arrival at Bennu, which ultimately reduces mission risk," Lauretta added.

After OSIRIS-REx performed its mission to asteroid Bennu, it will scan the outer space for "Trojan" asteroids by using its robotic eyes. OSIRIS-REx carries with it a payload of three cameras in order to hunt for "Trojan" asteroids called the OSIRIS-REx Camera Suite.

The camera suite is composed of the PolyCam, MapCam, and SamCam. Each of these has their specific functions in order to help the spacecraft complete its mission and to identify potential "Trojan" asteroids in space.

Reports say there are only six planets with "Trojan" asteroid as a companion including Earth. Earth's company is called 2010 TK7 and OSIRIS-REx will hunt for more "Trojan" asteroids that move in sync with the planet.