To accommodate a flood of information from a growing fleet of Mars probes, NASA is developing the first interplanetary communications satellite. Set for launch in 2009, the Mars Telecommunications Orbiter will become the hub of a network linking the current Mars Global Surveyor and the Mars Odyssey, along with Europe’s Mars Express Orbiter, en route to Mars, and the upcoming Mars Reconnaissance Orbiter. The latter will map swaths of the planet at a three-foot resolution.
“Handling all the data coming from Mars is becoming a challenge for us,” says Barry Geldzahler, the program executive for space operations in NASA’s Office of Space Science in Washington, D.C. “The Mars Odyssey is sending back unprecedented amounts of data, and with the Mars Reconnaissance Orbiter, we’ll have another order of magnitude more.”
Courtesy of NASA
Mars Reconnaissance Orbiter, scheduled to arrive in 2006, will send back a flood of visual information.
Global Surveyor and Odyssey are in low, near-polar orbits optimized for remote sensing. As a result, they will be able to make only brief contact with rovers or landers at midlatitudes—typically just one eight-minute contact each day. The Telecommunications Orbiter will allow hours of daily contact.
Transmitting readings from all those spacecraft would be difficult with radio signals, so the Telecommunications Orbiter will send information home via beams of laser light. This technique should allow a tenfold increase in the rate of data transmission. “With optical communications, the bandwidth will be as much as we need,” Geldzahler says.