During Orbital R phase, the OSIRIS-REx spacecraft will fly in a terminator orbit approximately 0.9 miles (1.4 km) above asteroid Bennu’s surface. This orbit is designated “Orbit R” because it is a sub-phase of the larger Reconnaissance phase.
Both the OCAMS and OVIRS instruments will be calibrated during the first week of Orbital R. The following two weeks are dedicated to global mapping, and the team will collect science data using the OTES, OVIRS, MapCam, and NavCam1 instruments. OTES will collect measurements in order to finalize the temperature maps for each of the four candidate sample sites. OVIRS will observe the local spectral information of each potential sample site. MapCam will map Bennu using the panchromatic filter and NavCam1 will collect optical navigation and particle monitoring images. REXIS will also be powered on in order to image Bennu’s X-ray fluorescence.
The remaining weeks of Orbital R will focus on optical navigation and particle imaging. Orbital R is scheduled to run through the beginning of January 2020. After the spacecraft departs orbit, it will begin the Reconnaissance B flyovers of the primary and backup sample sites. These two sites will be chosen in December.