Data Relay Constellation for high-performance links supply to future Martian missions.

Over the last decade, the scientific interest in Mars drastically increased. The planned growth of the number of robotic missions, together with the sensors' increasing data acquisition capabilities and the expected crewed expeditions, entails a significant increase in data flow between the Martian assets and Earth both in volume and frequency of contact. In particular, crewed missions would lead to the need for nearly continuous communication with Martian assets. The keystone to avoid the future Martian telecommunication deadlock resides in specialising assets on specific functionalities through infrastructures. In this regard, the paper proposes a distributed Mars-based orbiting system servicing as a communication relay for any scientific and technological mission operating on the red planet's surface. The paper explores the design of a small satellites Martian constellation to maximise the surface coverage and visibility time with respect to ground users while reducing the station keeping efforts of the assets. A relatively novel proposed approach is to exploit the so-called Trans Areostationary Orbits (TASO), which allow low drift of the spacecraft with respect to Mars' surface, with an improved orbital stability than the perfectly stationary orbits. The paper aims at extending the available options by exploring trajectories that leverage the third body gravitation from the two Martian moons, Phobos and Deimos, to possibly further improve stability, coverage of the surface, communication datarates, and manoeuvres costs in general. The costs include the operative phase, as well as all the transfers from Earth to the Martian sphere of influence.As a final contribution, the paper explores the concept of Linked, Autonomous, Interplanetary Satellite Orbit Navigation (LiAISON) (Hill, 2007) for the proposed constellation configurations, to verify the possibility of reconstructing the spacecraft states through relative-only measurements. [ABSTRACT FROM AUTHOR]