Transcript of OCAMS Instrument Profile


Narrator: How does one spacecraft image an asteroid from as far away as a million kilometers, or as close as just a few meters? Accomplishing this task is the job of OCAMS: the OSIRIS-REx camera suite.


NASA's OSIRIS-REx mission is headed to near-Earth asteroid Bennu, a remnant from the dawn of the solar system. OCAMS sits on the OSIRIS-REx instrument deck, which will face Bennu during orbit. It consists of three cameras built by the University of Arizona, each designed to provide the mission with a unique perspective.


PolyCam is a reflecting telescope with an eight-inch mirror and a narrow field of view, which will acquire both long-range and close-up images of Bennu. MapCam is a medium-angle camera, which will map Bennu in color. SamCam is a wide-angle camera that will record the most crucial moment of the OSIRIS-REx mission.


OSIRIS-REx will spend nearly two years traveling from Earth before approaching Bennu in 2018. PolyCam will be the first instrument to spot the asteroid, as a faint speck of light up to two million kilometers away. As OSIRIS-REx approaches Bennu, it will switch from navigating by using radar ranging from the Earth to using OCAMS to refine the asteroid's position and to ensure a smooth transition to proximity operations.


Over the next year, the OCAMS suite will scan Bennu at various resolutions, providing global maps and close-up images. MapCam will use its color filters for spectral imaging, revealing clues about the asteroid's composition through subtle changes in its color and brightness.


In 2019, OSIRIS-REx will make a series of close passes of Bennu, allowing PolyCam to image portions of the surface with sub-centimeter resolution. These images will prepare OSIRIS-REx for its most important task, which will be documented by the wide-angle SamCam.


After more than a year in orbit, OSIRIS-REx will slowly approach Bennu's surface to grab a sample of the asteroid. SamCam will capture the event in a series of rapid-fire images. This visual record will help scientists understand the context of the returned material. In 2023, OSIRIS-REx will deliver its sample of Bennu to Earth, where scientists will study the sample for decades to come.


OSIRIS-REx is investigating asteroid Bennu, and OCAMS will provide the first close-up look at this ancient remnant of the solar system – revealing clues to Bennu's history, and our own.