Earth to Mars: Developing Requirements for an Earth Orbiting Perimeter Truss Reflector for the Mars Environment

NASA’s “Expanding the Horizons of Mars Science” report emphasizes the need for low-cost, smaller satellites for future Mars missions, accompanied by enhanced Mars-Earth telecommunications. Current Mars telecom relay orbiters cost $400M–$800M (adjusted for inflation), with rising costs outpacing budgets. Leveraging deployable antennas, such as Tendeg’s perimeter truss reflector (PTR), could enable small spacecraft (<500 kg) to match the capabilities of larger relays at a fraction of the cost (>$100M per spacecraft). To reuse a 3-meter GEO PTR for Mars, it is important to develop the requirements for the Martian application of the antenna, and understand what differences exist between GEO and Mars. Key requirements include packaging and spacecraft interface, optical prescription and geometric accuracy, and environmental. Environmental requirements include those related to vibration, radiation, thermal and aerobraking. Future work will validate the PTR design against Mars-specific requirements defined here, focusing on cold-temperature performance.