Aug 03, 2020

This week, OSIRIS-REx continued planning activities for Matchpoint rehearsal. On Jul. 25, the spacecraft conducted a Sample Mass Measurement (SMM) bake-out activity. During this maneuver, the spacecraft rotates as it will during the SMM activities, that are designed to measure the amount of sample collected after OSIRIS-REx touches the surface of Bennu. This bake-out is designed to expose the Sample Return Capsule to the sun to rid it of any accumulated condensate or frozen volatiles in areas of the SRC that are shaded during normal operations but exposed during the SMM. The release of such volatile material imparts a small force on the spacecraft that can corrupt the measurement of the sample during the actual SMM, so the bake-out is an attempt to “clean up” usually shady regions of the SRC before the SMM activity, similar to cleaning the dust under your sofa before important visitors come over. The SMM bake-out is the first activity leading into the second and final sample rehearsal on Aug. 11 where the spacecraft will descend to within approximately 40 m from Bennu’s surface.