Martian Positioning System (MPS)

 

Power Systems:

Our individual GPS satellites have been designed to minimize cost without degrading the functionality of our overall system.  Power for the satellites will be provided by two sources.  The first source consists of two large panels with solar cells placed on each side of the panel to improve efficiency (1.5 meters x 6 meters x 2 panels facing the sun at any given time) to provide up to 2500W of power for standard operations. The Triple Junction GaAs based solar cells have been selected due to their high efficiency of 25% (these lead to reduced weight and wingspan) and broad absorption spectrum (the solar irradiance at Mars is 550 W/m^2 in Space).  In addition to this, NiMH/NiCd battery supplies will also be on board to provide power during loss of power from the solar cells, specifically during solar eclipses of the satellite due to Mars (approximately 1.5 hours a day).  Boosters will be onboard as well to provide orbital corrections as well as the required thrust for the Hohmann transfer.  With the size of the solar cells taken into account, the final wingspan of our satellite will reach roughly 15 meters with an estimated weight of 2000 kg, based on average GPS satellite statistics.  This should provide an estimated lifetime, based on NASA statistics, of roughly 9-10 years.  Four satellites from one constellation will also be outfitted with our long-haul communication system using the Deep Space Network (DSN) which will transmit in bursts back to Earth in order to reduce power consumption.  

The Mars Rover, based on specs from the Phoenix Rover (below), will cost approximately $125 million to construct, with a final weight of 350 kg.  The rover will also deploy the same solar/battery system as our satellites, however more batteries will be needed due to common dust storms on Mars limiting solar power for long durations.

  

For a more detailed cost analysis, please see the Budget and Timeline System Component.