Osiris-REX’s PolyCam captured the motion of asteroid Bennu against the starry background over an hour.
NASA / Goddard / University of Arizona.

It has been almost two years since NASA launched its asteroid hunter OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer) to space, and for the first time, it has captured a glimpse of its target.

OSIRIS-REX is heading to the asteroid Bennu, which is about the size of a mountain and consists of the ancient remains from when our solar system was created over 4.5 billion years ago. The idea is that OSIRIS-REX will land on Bennu and collect material – just like the Japanese Hayabusa 2 will do on the asteroid Ryugu – then return to Earth.

The orbit of Earth, OSIRIS-REx and asteroid Bennu, from launch, through Earth flyby assist, to asteroid rendezvous. NASA/JPL-Caltech

The images shown in the animation above was photographed OSIRIS-REx when it was approximately 2.25 million kilometers from Bennu. The spacecraft has traveled approximately 1.77 billion kilometers (1.1 billion miles) since its September 8, 2016 launch, and is scheduled to arrive at Bennu on December 3, 2018.

“Now that OSIRIS-REx is close enough to observe Bennu, the mission team will spend the next few months learning as much as possible about Bennu’s size, shape, surface features, and surroundings before the spacecraft arrives at the asteroid,”

– Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson.

As OSIRIS-REx approaches the asteroid, the spacecraft will use its science instruments to gather information about Bennu and prepare for arrival. The spacecraft’s science payload comprises the OCAMS camera suite (PolyCam, MapCam, and SamCam), the OTES thermal spectrometer, the OVIRS visible and infrared spectrometer, the OLA laser altimeter, and the REXIS x-ray spectrometer.

After arrival at Bennu, the spacecraft will spend the first-month performing flybys of Bennu’s north pole, equator and south pole, at distances ranging between 19 km and 7 km (11.8 and 4.4 miles) from the asteroid. These maneuvers will allow for the first direct measurement of Bennu’s mass as well as close-up observations of the surface.

The orbit of Earth, OSIRIS-REx and asteroid Bennu, from launch, through Earth flyby assist, to asteroid rendezvous.
NASA/JPL-Caltech

The spacecraft will extensively survey the asteroid before the mission team identifies two possible sample sites. Close examination of these sites will allow the team to pick one for sample collection, scheduled for early July 2020. After sample collection, the spacecraft will head back toward Earth before ejecting the Sample Return Capsule for landing in the Utah desert in Sept. 2023.