Proximity operations about noncooperative resident space objects (RSOs) is a current area of research with the intent to enable many useful on-orbit missions. One method of performing passive proximity operations about a noncooperative RSO uses two cameras to obtain stereo line-of-sight data to the RSO in order to fully resolve the relative position and velocity of the RSO and navigate about it. An overview of the MR and MRS SAT mission, in which a stereoscopic imager is used aboard MR SAT to navigate about MRS SAT (a mock noncooperative RSO) is presented. The developed hardware and algorithms used by the stereoscopic imaging sensor, as well as the guidance, navigation, and control subsystems, are presented. A software-in-the-loop simulation is presented to demonstrate the expected on-orbit performance of the MR and MRS SAT mission.