NASA New Spacecraft Wall-E and Eva Will Battle Deadly Radiation to Reach Mars

The 2008 film Wall-E, whose star is seen here attending a German premiere, inspired nicknames for two Mars-bound tiny satellites. Andreas Rentz/Getty Images

If all goes well, NASA's next mission, a Mars lander, will launch on May 5. But that robot won't be alone—it will have two tiny hitchhiker satellites, the first spacecraft of their size to leave the safety of Earth's orbit.

The satellites are each about the size of a briefcase and will run a separate mission from that of the main lander. Their creators have nicknamed the pair Wall-E and Eva, in honor of characters from the Pixar film, thanks to the scene in which Wall-E uses a fire extinguisher to dance through space, which mimics how these two real spacecraft will move.

If they successfully survive their voyage, the satellites, formally known as MarCO-A and MarCO-B, will become communication relay stations around Mars.

Read more: Mars's Two Tiny Moons Were Formed After an Asteroid Hit the Planet, New Theory Suggests

"These are our scouts," Andy Klesh, chief engineer of the MarCO project, said in a press release. "CubeSats haven't had to survive the intense radiation of a trip to deep space before, or use propulsion to point their way towards Mars. We hope to blaze that trail."

CubeSats, the formal name for these small satellites, have become extremely popular for use in Earth's orbit, since they're relatively cheap to develop and launch. More than 700 of these miniature satellites have been sent to space so far.

But unlike any of their fellow CubeSats, after launch, the MarCO satellites will be driven by a compressed gas that's often used in fire extinguishers. Each satellite can shoot that gas in eight directions in order to steer. (Other CubeSats use electromagnetic steering in combination with the magnetic field that surrounds Earth.)

The new steering mechanism was necessary because to date, every single CubeSat satellite has stayed in orbit around Earth. Wall-E and Eva will be the first to stray farther, and that means they'll face huge threats that other CubeSats have avoided—most notably radiation, which damages human and robotic space explorers alike.

If they do survive the months-long, perilous journey to Mars, they'll become relay messengers, picking up signals from the InSight lander as they pass overhead and then sending those signals on to Earth as they come out from behind Mars. That should make communication with the red planet much faster. But it's a low-risk experiment: InSight will still be able to send signals directly to Earth if the CubeSats don't make it.