MarCO success vindicates use of cubesats on deep space missions

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PASADENA, Calif. — The success a pair of cubesats achieved in relaying telemetry from NASA’s InSight Mars lander demonstrates that such spacecraft can play increasing roles in future deep space missions, spacecraft designers believe.

The twin Mars Cube One, or MarCO, cubesats launched as secondary payloads with the InSight spacecraft in May and flew by Mars as InSight landed on the planet. The cubesats, intended primarily as technology demonstrations, were designed to provide a realtime relay of telemetry from InSight during landing, without which it would have been hours before controllers knew if the spacecraft had landed successfully.

Although NASA emphasized the experimental nature of the cubesats prior to the landing, the MarCO spacecraft performed as intended, receiving the UHF telemetry from InSight during its entry, descent and landing phase and rebroadcasting it at X-band frequencies received by NASA’s Deep Space Network.

“MarCO was there to relay information back from InSight in real time, and we did that extraordinarily well,” said Andy Klesh, MarCO chief engineer, at a press conference at the Jet Propulsion Laboratory here Nov. 26 two hours after the InSight landing. “We had no dropped frames, no dropped data along the way.”

In addition to the InSight telemetry, one of the cubesats, MarCO-B, returned an image of Mars taken shortly after the landing, as the spacecraft was passing 6,000 kilometers from the planet. “We had one more gift that we could give,” Klesh said to applause from the audience in the press conference auditorium as he revealed the image. “This image is really our farewell to InSight, our wish for good luck and our farewell to Mars itself.”

The MarCO primary mission will last about two more weeks, he said. The two spacecraft will return other data collected during the flying, including telemetry about the health of the cubesats themselves and potentially other images of Mars taken during close approach.

The MarCO-A cubesat also indirectly performed science during the flyby as its radio signals were occluded by the planet as it passed behind Mars. Measurement of the changes in signal as it passed through the planet’s atmosphere just before and after being blocked by the planet itself could provide information about atmospheric conditions. “With that, we’re actually doing atmospheric science as we’re passing by Mars, and we’ll be digging through that data as well,” Klesh said.

The success of MarCO demonstrates that such small satellites — each MarCO satellite is a six-unit cubesat — can perform useful missions beyond Earth orbit, opening up new opportunities for such spacecraft in the future. “This team of really mostly part-timers on the project has proven the technology we were trying to demonstrate with this mission, being able to support a large craft like InSight,” he said. “We can take a smaller, focused, more riskier mission out into the solar system and take advantage of new opportunities.”

NASA has increasingly shown an interest in using cubesats and other small satellites for a variety of science missions, initially in Earth science and heliophysics but now also astrophysics and planetary science. NASA hasn’t committed to a MarCO-like mission for its next Mars lander, the Mars 2020 rover, but Klesh said the success of MarCO has opened the door to that and other uses of smallsats in deep space.

“We’ve shown that this type of craft can support these types of missions, should that be needed,” he said. “We’ll be working on opportunities as we go to see where they’re necessary and how well we can support them in the future.”

Prior to the landing, project officials had hinted they were looking at options for an extended mission for MarCO, but were focused at the time on supporting the InSight landing. “We are discussing with [NASA] Headquarters on what we might do” with an extended mission, Klesh said. That included collecting engineering data to assess the “survivability” of the spacecraft and “seeing what other great science and lessons we can pull from those craft.”

“We do look forward to those lessons being used on future missions,” he added. “There are many future smallsats and cubesats that are in work and funded by NASA at this point, and we look forward to more concepts into the future.”