Mars network: a Mars orbiting communications and navigation satellite constellation

Mars has become the focus of an unprecedented series of missions spanning many years, involving numerous nations and evolving from robotic to human exploration. Elements will be dispersed widely in longitude and latitude over the surface of Mars. Some surface elements like rovers, balloons and airplanes will be mobile. Other elements like sample canisters will orbit Mars. Finally manned sites will require broadband, 24hr connectivity to earth. The challenge has been to develop an architecture and technology roadmap that will anticipate the needs of this evolving mission set. NASA's Jet Propulsion Laboratory has begun development of this architecture and its associated technologies. For cost reasons, the early phases of this constellation will employ small spacecraft that ride as an auxiliary payloads on Ariane launches. A properly designed constellation of six or fewer spacecraft in low altitude, 800 km, orbit around Mars is capable of providing global communications and navigation performance:-100's of Mbits per Martial day from elements at any locations on the Martian surface. -10 m accuracy position fix to a surface element located anywhere on the planet in an average time of 2 hours or less.