JPL Studies Missions, Tech for Future Interplanetary Cubesats

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LOGAN, Utah — As NASA’s Jet Propulsion Laboratory prepares its first two interplanetary cubesat spacecraft for launch next year, engineers are examining what other solar system missions such spacecraft could perform and the key technologies needed to enable them.

The Mars Cube One (MarCO) mission will fly a pair of six-unit cubesats to serve as real-time radio relays for NASA’s InSight Mars spacecraft as it enters the atmosphere. Most of the components for the two spacecraft have arrived at JPL, and assembly is slated to begin this week, said JPL’s Andrew Klesh in an Aug. 11 presentation at the Conference on Small Satellites here. The spacecraft are scheduled for completion Dec. 1 and launch in March 2016.

MarCO is one of several interplanetary cubesat missions under consideration at JPL. “We have really big plans to take these cubesats far into the solar system,” said Sara Spangelo of JPL in a presentation at the CubeSat Developers’ Workshop here Aug. 9.

Concepts for interplanetary cubesat missions JPL has studied, she said, range from spacecraft that hover above the surface of an asteroid or comet to landers and penetrators. Those spacecraft could accompany larger missions, or be free flyers that serve as precursors for later missions. “They have great potential for science enhancement as well as exploration value,” she said.

Missions beyond Earth orbit carry with them a number of technical challenges for cubesat-sized spacecraft, including power, propulsion, and communications. In an Aug. 11 presentation at the conference, Spangelo said advances in electric propulsion could enable cubesat missions throughout the inner solar system.

One example she discussed at the conference used a plasma thruster called the Cubesat Ambipolar Thruster under development at the University of Michigan. That thruster could allow six-unit cubesats, with a total mass of less than 20 kilograms, to go into orbit around Mars after a 13-month trip from Earth.

“Emerging electric propulsion systems that we’ve been hearing about over the last few years are extremely exciting,” she said. “They’re game-changing in terms of what cubesats will be able to do.”

Another team of JPL is working on a deployable antenna that fits into a six-unit cubesat that allows Ka-band communications at data rates far higher than possible today. Jonathan Sauder said in an Aug. 11 conference presentation that the antenna could increase data rates by a factor of 10,000 compared to X-band patch antennas mounted on the body of a cubesat.

The MarCO team, though, is focused on completing their two spacecraft and carrying out their data-relay mission. After his presentation, Klesh was asked if he was considering any extended mission for the spacecraft after they fly past Mars. “As far as the team is concerned, our primary mission is over at Mars and they are not allowed to think about anything beyond that until we get to that point,” he said. “Launch delivery is just too soon right now.”