Mars Trojan Orbits for Continuous Earth-Mars Communication

This investigation selects orbits appropriate for a deep-space relay terminal to ensure continuous communication between Earth and Mars. Geometric constraints are derived and are used to evaluate the fitness of several periodic orbit families in the sun-Earth and sun-Mars circular-restricted three-body systems. It is determined that Mars Trojan orbits provide the best solution. Families of these orbits are presented and studied for stability in a multibody model. It is shown that with no station-keeping, appropriately chosen orbits satisfy the geometric telecommunication constraints for decades. Outbound transfer costs from Earth and orbit insertion costs are computed in both Keplerian and ephemeris-level multibody regimes. The use of an outbound Mars flyby significantly lowers the orbit insertion cost.