OSIRIS-REx Asteroid Sample-Return Mission

Abstract

The primary objective of the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission is to return pristine samples of carbonaceous material from the surface of a primitive asteroid. The target asteroid, near-Earth object (101955) Bennu, is the most exciting, accessible, and volatile- and organic-rich remnant from the early Solar System. OSIRIS-REx returns a minimum of 60 g of bulk regolith and a separate 26 cm2 of fine-grained surface material from this body. Analyses of these samples provide unprecedented knowledge about presolar history, from the initial stages of planet formation to the origin of life. Prior to sample acquisition, OSIRIS-REx performs comprehensive global mapping of the texture, mineralogy, and chemistry of Bennu, resolving geological features, revealing its geologic and dynamic history, and providing context for the returned samples. The instruments also document the regolith at the sampling site in situ at scales down to the sub-centimeter. In addition, OSIRIS-REx studies the Yarkovsky effect, a non-Keplerian force affecting the orbit of this potentially hazardous asteroid (PHA), and provides the first ground truth for telescopic observations of carbonaceous asteroids.