On November 14, SSPI presented a first-place cash award to students from the SEDS Chapter at the University of Illinois Urbana Champaign for a mission proposal called MOSIAC: Mars Orbiting Satellites for Advanced Interplanetary Communication. The winners of our first prize were team leader Chris Lorenz and 14 teammates (see below) from the Illinois Space Society. Their industry Mentor was Denis Curtin, formerly COO of XTAR and a member of SSPI’s Satellite Hall of Fame.
The competition asked student teams to approach design of a Martian satellite network in two phases. Within the first ten years, the communications network would be providing a minimum of 6 hours of connectivity per sidereal day to robotic landers conducting research and building a habitat for humans. Within another ten years, network would would need to provide connectivity between Mars and Earth for 98% of the sidereal day to support human exploration and colonization.
From SmallSats to Solar Eclipse Relays
In a detailed analysis, the team proposed the construction of 40 identical small sats based on the TerraSense 300 commercial smallsat bus. In the first phase, a constellation of smallsats would be launched four at a time aboard an Atlas V or its future variants, transferred to Mars and placed into low orbits at 1,507 km altitude. A minimum of six active satellites would provide continuous coverage. They would communicate directly with Earth using X-band at a low data rate sufficient for robotic exploration.
In the next phase, the team would place identical smallsats into a higher 10,700-km orbit to provide higher-bandwidth continuous of the surface in support of human exploration. Due to the higher altitude, they would depend on the deployment of higher-powered transmitters on surface equipment to close the link and provide a high data rate. These would be augmented by a pair of optical communication relay satellites (LACOR), based on the GEOStar-2 bus from Orbital ATK, sent to the Sun-Mars L1 Lagrange point. Communicating with the smallsats over X-band, the LACOR relays would enable data rates of up to 80 Mbps.
In a final phase, the MOSAIC architecture requires a Solar Eclipse Relay (SER) satellite at the Sun-Earth L4 point to fill the coverage gap that occurs when the Sun blocks communications between Earth and Mars. The satellite hop becomes complex – from smallsats to LACOR to SER and then to Earth – but it ensures 24x7x365 connectivity.
You can read the full report of the U Illinois team here, as well as see an interview with all the members of the group. See a full description of the Satellites Around Mars competition, conducted in partnership with the Students for the Exploration and Development of Space.
We congratulate our winning teams and look forward to organizing a new competition next year with our partner, the Students for the Exploration and Development of Space.