While everyone was caught up in the spectacle of NASA’s latest Mars landing, there was another important event happening nearby. Two tiny cubesats traveling along with InSight came online, beaming data back to Earth from InSight. No one has ever sent one of these small, off-the-shelf satellites so far away before. Could this herald a new era in low-cost exploration of the solar system?
The spacecraft, known as MarCO-A and MarCO-B (Mars Cube One), went to space aboard the same rocket that launched InSight in May of this year. However, they didn’t share any systems with NASA’s Mars lander. They just coasted along with InSight on the same Mars-bound trajectory. They floated along for 301 million miles (484 million kilometers) with InSight, but they aren’t landers. The dinky spacecraft floated on past Mars but not before proving themselves worthy of a deep space assignment.
Cubesats are low-cost satellites designed for basic space research. They’re called cubesats because a single unit (or 1U) is a 10-centimeter cube. The smallest cubesats are 1U, but some missions call for 2U, 3U, or larger cubesats. In the case of Mars Cube One, NASA went with a 6U design. The total cost of the project was $ 18 million, significantly less than other deep space probes.
NASA initially tested these tiny craft with a photo of Earth several weeks after launch, and then we didn’t hear anything else from them until InSight had its big moment. The cubesats came online and used their experimental high-gain antennas to relay data from InSight back to Earth, thus proving small-scale satellites are a viable way to explore the solar system.
The MarCO mission relied on very little custom NASA hardware. MarCO-A and MarCO-b (nicknamed EVE and WALL-E, respectively) both had an off-the-shelf camera module. NASA pinged them to get photos of Mars, but MarCO-A’s system didn’t work correctly. MarCO-B managed to beam back some shots of Mars, from which NASA will be able to glean some atmospheric data. The photo above came from the satellite at an altitude of 4,700 miles (7,600 km) as the probes drifted away from Mars.
MarCO-A and MarCO-B only have rudimentary cold-gas propulsion likened to a fire extinguisher — that’s why the team jokingly nicknamed the spacecraft after the fire extinguisher-wielding robots from the Pixar film. They can’t make major course changes, but NASA hopes their systems will work long enough to send back some data about objects they may encounter as they near the asteroid belt. There’s no guarantee that will happen, but there will almost certainly be more deep space cubesats following in EVE and WALL-E’s footsteps.