Challenges in Orbit Determination for Deep-Space Science CubeSats: LICIACube and ArgoMoon

CubeSats were born to be a cheap alternative for relatively short low Earth-orbiting missions. The extensive tests on field have proven that CubeSats are capable to conduct also deep-space missions,even though with lower performances depending on off-the-shelf payloads. The idea of coupling one or more CubeSats to support a classical deep space probe could be useful to reduce the mission costs while increasing the scientific objectives. For instance, CubeSats could be used to split mission tasks, to perform gravity investigations using formation flight (Hera-Juventas), or dedicated optical observation (LICIACube, ArgoMoon). The costs could be additionally reduced by releasing the CubeSats once reached the investigation situ. However, CubeSats' payload and onboard computation limits, smaller non-directional antennas set a tricky challenge to the Orbit Determination (OD) and Navigation (NAV) tasks. SLS. Recently, the Mars Cube One (MarCO) mission has demonstrated the capabilities of the CubeSats in deep- space environment. In the following, we will present the challenges in the navigation of two deep-space CubeSats, coordinated by the Italian Space Agency (ASI): LICIACube and ArgoMoon. Both the spacecrafts are designed, manufactured, and tested by the Italian company Argotec that will also operate the spacecrafts.