A Sat-to-Sat Inspection Demonstration with the AeroCube-10 1.5U CubeSats

In the summer of 2020, the pair of AeroCube-10 1.5U CubeSats completed a series of mutual proximity operations as close as 22 meters separation and captured several sets of satellite-to-satellite resolved imagery, inspecting all faces of a vehicle in each pass with a resolution less than 8 mm. AeroCube-10 was designed and built by The Aerospace Corporation with the primary missions of atmospheric science and the maturation of nanosatellite technologies, including a new star tracker design, warm-gas propulsion system, GPS receiver, and a low-noise focal plane. Investigating the possibility of using CubeSats for satellite inspection missions, the AeroCube-10 team designed an experiment using these technologies in ensemble to bring the vehicles close together and demonstrate the feasibility of inspection missions in a package as small as 1.5U. Starting from a separation of more than one thousand kilometers, over the course of several weeks maneuvers executed with the AeroCube-10 propulsion unit brought the vehicles closer together, using proven formation keeping techniques to ensure safety of flight as the range dropped below 100 meters. The first imagery while in a natural-motion circumnavigation (NMC) was performed at a range of 64 meters. Gaining confidence in AeroCube-10’s capabilities, the operations team decreased the size of the NMC several times, obtaining imagery at 30 meters and then 22 meters. AeroCube-10 completed roughly one fourth of an NMC during each imaging run, and the observing satellite collected images of all faces of the target as it orbited around. At such close range, the inspection images clearly show individual solar cells, patch antennas, the exposed atmospheric probe magazine payload, the satellite’s miniature radiation dosimeter, and other features. AeroCube-10's activities have demonstrated for the first time the feasibility of prolonged inspection activities in a very small form factor and, by closing from great distance and then entering NMC, proved that the nanosatellite platform has the potential for multiple-target inspection, as may be necessary for space-debris removal or constellation-inspection missions.