Mars Relay Network

Five spacecraft currently in orbit about the Red Planet make up the Mars Relay Network to transmit commands from Earth to surface missions and receive science data back from them. Clockwise from top left: NASA’s Mars Reconnaissance Orbiter (MRO), Mars Atmospheric and Volatile EvolutioN (MAVEN), Mars Odyssey, and the European Space Agency’s (ESA’s) Mars Express and Trace Gas Orbiter (TGO).