Orbiters first, humans next? NASA/JPL/USGS

NASA is getting into the nitty-gritty of how to build a Mars orbiter that would support human ground missions. The agency awarded contracts to five engineering companies – Boeing, Lockheed Martin, Northrop Grumman, Orbital ATK and Space Systems/Loral – to show what kind of spacecraft each is capable of building for a potential mission in the 2020s.

The current Mars orbiters relay about 95 per cent of the data from rovers on the Red Planet. The other 5 per cent is sent directly from rovers, but this takes much longer and can only be carried out at certain times. “Those orbiters are getting long in the tooth,” says Richard Zurek at the Jet Propulsion Laboratory in Pasadena, California. The next generation will need better propulsion, better imaging capabilities and better communication systems to support a human mission.

Designing solar-electric powered orbiters will be key for these goals, says Zurek. Solar-electric propulsion, already in use in Earth-orbiting satellites, works by harnessing the sun’s energy to accelerate ions and propel the craft.


Such fuel-efficient satellites would be able to fly close to the Martian surface to get high-resolution pictures of good landing sites and carry new kinds of communication systems to cooperate with a ground crew.

An optical communications system could use a laser to send data back to ground control on Earth with high fidelity. But the spacecraft would need to be able to point itself very precisely to aim the laser at receivers on Earth.

NASA would also like the orbiter to be able to return to Earth with Martian samples, says Zurek. In this scenario, the Mars rover scheduled for a 2020 launch would send up a capsule of surface samples, which the new orbiter would snatch up and carry home.

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