Published : Tuesday, February 5, 2019 | 4:32 PM
Scientists working on the Mars Cube One (MarCO) mission at the Jet Propulsion Laboratory in Pasadena have not heard from the pair of briefcase-sized spacecraft for over a month now, raising concerns the twins may have reached their limit and run out of power after a successful Mars fly-by.
When InSight landed on the red planet in November, MarCO – composed of CubeSats nicknamed EVE and WALL-E after Pixar film characters – relayed the lander’s signals to mission control, beaming back data at each stage of the descent to the Martian surface.
WALL-E sent back stunning images of Mars as well, while EVE performed some simple radio science – all these with experimental technology at the paltry sum of $18.5 million; a fraction of what most space missions do.
Now estimated to be millions of miles past Mars, WALL-E was last heard from on Dec. 29; EVE, on Jan. 4.
The mission team at JPL has several theories for why the spacecraft have been silent.
WALL-E has a leaky thruster, and attitude-control issues could be causing them to wobble and lose the ability to send and receive commands. The brightness sensors on the CubeSats, which allow them to stay pointed at the Sun and recharge their batteries, could be another factor. The farther the MarCOs are, the more precisely they need to point their antennas to communicate with Earth.
The MarCOs won’t start moving toward the Sun again until this summer. The team will reattempt to contact the CubeSats at that time, though it’s anyone’s guess whether their batteries and other parts will last that long.
Even if they’re never revived, the team considers MarCO a spectacular success.
“This mission was always about pushing the limits of miniaturized technology and seeing just how far it could take us,” Andy Klesh, the mission’s chief engineer at JPL, said. “We’ve put a stake in the ground. Future CubeSats might go even farther.”
With EVE and WALL-E’s success, NASA is set to continue launching a variety of new CubeSats in the coming years. JPL said they still have a number of the critical spare parts that can be used to build more CubeSats. Several of these systems were provided by commercial vendors, making it easier for other CubeSats to use them as well.
“There’s big potential in these small packages,” John Baker, the MarCO program manager at JPL said. “CubeSats – part of a larger group of spacecraft called SmallSats – are a new platform for space exploration that is affordable to more than just government agencies.”
For more information about the MarCO mission and CubeSats, visit www.jpl.nasa.gov/cubesat/missions/marco.php.