The camera suite for Nasa's first mission to return samples of an asteroid to Earth has been delivered for installation to the spacecraft.
The Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) mission is slated for launch in September 2016. It will study the 500m-wide near-Earth asteroid Bennu.
When the spacecraft achieves its rendezvous with Bennu in 2018 it will survey the asteroid, obtain a sample and return it to Earth by 2023. Completing this mission will require it to locate and map the asteroid before choosing a safe and interesting place to land to collect a sample, which is where the camera suite comes in.
"This is another major step in preparing for our mission," said Mike Donnelly, OSIRIS-REx project manager at Nasa's Goddard Space Flight Center in Greenbelt, Maryland. "With the delivery of the camera suite to the spacecraft contractor, we will have our full complement of cameras and spectrometers."
The three-camera instrument suite, known as OCAMS (OSIRIS-REx Camera Suite), was designed and built by the University of Arizona's Lunar and Planetary Laboratory and has now been delivered to Lockheed Martin Space Systems in Denver where the spacecraft is being constructed.
A small telescope called Polycam is the largest of the three cameras and will be used to acquire the first images of Bennu from a distance of two million kilometres, as well as provide high-resolution imaging of the sample site.
Another sensor called MapCam will search for satellites orbiting the asteroid and dust plumes around Bennu, map the asteroid in colour and provide images to construct topographic maps. A final camera called SamCam will document the sample acquisition event and the resulting collected sample.
"PolyCam, MapCam and SamCam will be our mission's eyes at Bennu," said Dante Lauretta, principal investigator for OSIRIS-REx at the University of Arizona, Tucson. "OCAMS will provide the imagery we need to complete our mission while the spacecraft is at the asteroid."
Nasa believe data generated by the mission could prove useful in planning any potential missions designed to prevent an asteroid colliding with Earth, should this prove necessary, though the main hope is that Bennu will hold clues to the origin of the solar system and the source of water and organic molecules that may have seeded life on Earth.
"The most important goal of these cameras is to maximize our ability to successfully return a sample," said OCAMS instrument scientist Bashar Rizk from the University of Arizona, Tucson.
"Our mission requires a lot of activities during one trip: navigation, mapping, reconnaissance, sample site selection and sampling. While we are there, we need the ability to continuously see what is happening around the asteroid in order to make real-time decisions."