Assessing the Global Availability and Reliability of the Mars Network, a Proposed Global Navigation Satellite System for Mars

In 1999, the NASA Jet Propulsion Laboratory presented a proposal for a six-satellite navigation and communication network for Mars called the Mars Network. In this paper the Mars Network proposal is evaluated in terms of availability, accuracy, and reliability as a function of position and time by simulating network geometry for users distributed across the planet. The Network is found to provide the best service to users in equatorial and polar regions but shows significant deficiencies for mid-latitude users. Instantaneous positioning is limited because of the small number of satellites in the constellation, meaning that users will have to wait for an appropriate geometry to obtain solutions. The lack of redundant observations also means that blunder detection will be difficult and will only be possible for a user making multiple observations over time. The addition of a height constraint to reduce the number of unknowns is shown to increase the range of positions on the planet where instantaneous positioning will be possible; however, instantaneous positioning is available less than one fifth of the time at low latitudes and is still not available at the poles.