It's been a big week for Mars news. On Monday, the first trailer for the upcoming Ridley Scott movie The Martian was released, and on Tuesday, the Japan Aerospace Exploration Agency (JAXA) unveiled a new sample-return mission to Mars's moons, slated for launch sometime in the 2020s.
CubeSats are blocklike microsatellites that typically measure 10 centimeters on each side, allowing for one liter of volume. Their small size and low cost has democratized satellite access, allowing nonprofits, universities, and even elementary schools to develop their own orbiters. Dozens of CubeSats are currently operating in low-Earth orbit, but scientists have never deployed them in deep space before.
Enter: The Mars Cube One mission, or MarCO. The mission's twin CubeSats will be about six times the standard liter size, with dimensions of 14.4 inches by 9.5 inches by 4.6 inches. Each of them will be outfitted with a radio capable of receiving and transmitting UHF and X-band wavelengths.
The plan is to bundle the MarCO satellites in with the InSight lander when it launches next spring, but then separate the three spacecraft once they are in space. "MarCO will fly independently to Mars," said Jim Green, director of NASA's planetary science division, in a statement.
The MarCO cubes will make their own way to Mars, becoming the first CubeSats ever to travel through deep space, or to visit another planet. If all goes well, they will arrive at Mars alongside the InSight lander in September 2016. But where InSight will land on the planet, the CubeSats are destined to only briefly fly by it. Maybe one day, CubeSats will be sent to orbit Mars, but this mission is more of a proof-of-concept test.
That said, MarCO will play a key role during InSight's entry, descent, and landing phases. As it makes its way down to the Martian surface, InSight will be radioing information to the Mars Reconnaissance Orbiter (MRO) on the UHF frequency, but MRO can't receive and transmit this information simultaneously.
Mission leads back on Earth will have to wait for it to process the lander's messages before it passes them along. According to NASA, "confirmation of a successful landing could be received by the orbiter more than an hour before it's relayed to Earth."
The CubeSats, meanwhile, can receive UHF frequencies and immediately transmit them as X-band messages. So in addition to testing out the concept of deploying CubeSats in deep space, MarCO will, in theory, be able to give mission leads an early heads-up about the status of the InSight lander.
All in all, it will be an interesting first step in extending the reach of microsatellites beyond their comfort zone in low Earth orbit.