Preliminary geometry analysis for a solar system navigation constellation

The interest in solar system exploration missions is increasing including the use of small spacecraft. ESA’s Moonlight and Marconi projects aim to provide navigation infrastructure on Moon and Mars respectively. This paper proposes to study a navigation constellation providing ubiquitous radio navigation in the solar system supporting navigation needs beyond Moon and Mars. A preliminary strategy to choose the orbits for solar system navigation satellites based on distance to target regions, position dilution of precision (PDOP) at target regions and delta-v to launch the satellites is formulated. Using said strategy, it was found that a combination of two satellites in the Sun-Mars Lagrange points and three satellites in an inclined heliocentric orbit can provide a very good PDOP of 2.6 for the inner solar system. The results can form the basis for further work on geometry optimizations, operational concepts and system design for solar system navigation and to explore synergies with solar system communication initiatives.