Radio Occultation Results from MarCO, The First Interplanetary Cubesat Mission

On May 5, 2018, NASA launched the first interplanetary cubesat mission: Mars Cube One (MarCO). MarCO-A and MarCO-B are twin cubesats that were designed as communications relay for InSight during its Entry, Descent and Landing (EDL) on November 26, 2018. After InSight's successful EDL, the MarCO spacecraft continued on their flyby of Mars. MarCO-A had favorable geometry that allowed for a radio occultation observation of the planet. This was the first interplanetary data signal transmitted by a cubesat and received at NASA's Deep Space Network using open-loop recordings. Here we present an investigation of the MarCO radio science measurements, results of the MarCO-A radio occultation observation, and the expected science performance from a MarCO like cubesat. We compare observations with Martian atmospheric and ionospheric model simulations to evaluate the performance of the MarCO radio occultation. This investigation will improve our understanding of engineering and science constraints for future interplanetary cubesats, evaluating their ability to investigate planetary atmospheres, ionospheres, and rings using radio occultation measurements; probe the interior of a planetary body with gravity measurements and measure surface characteristics with bistatic scattering.