WALL-E and EVE fly through space. The twin satellites follow NASA’s InSight spacecraft 300 million miles—all the way to Mars!

WALL-E and EVE are CubeSats. CubeSats are small satellites sent to space to send back information. WALL-E and EVE are each the size of a briefcase. They hitch a ride on the same rocket that launched InSight in May, 2018 on its nearly seven-month flight to Mars. CubeSats always share rockets. They’re too small and inexpensive to need their own launch.

InSight is made to land and work on Mars. But the mini satellites fly past the planet. Their job is to send information about InSight’s landing back to Earth as quickly as possible. They follow 6,000 miles behind InSight. Scientists at NASA keep them apart so the satellites will not collide with the spacecraft. WALL-E and EVE are also 6,000 miles apart from each other. 

Do you recognize the satellites’ names? They come from the 2008 animated film WALL-E. In the film, WALL-E uses a fire extinguisher to propel through space. In reality, the CubeSats steer through space the same way compressed gas shoots out of a fire extinguisher. Although WALL-E the CubeSat leaks fuel most of the way, flight controllers work around the problem. Meanwhile, EVE flies beautifully the whole time.

In November, scientists wait and watch as InSight prepares to land. Will WALL-E and EVE stay quiet? Or will they let scientists know what is happening? It should take less than a minute for InSight to send a signal to the CubeSats. It will take eight minutes and seven seconds more for a radio signal from the mini satellites to get from Mars to Earth… if the CubeSats cooperate.

InSight plunges through the red skies of Mars. Scientists on Earth hold their breath. A flight controller calls out, “Touchdown confirmed!” The scientists start to cheer. They leap out of their chairs. They dance and hug. InSight has survived the landing! WALL-E and EVE have sent back the good news, along with InSight’s first snapshot of Mars.