These 2 moon rovers used cameras and lasers to hunt for simulated water ice — and one looks like WALL-E

In a scene that could be out of a Pixar movie, two adorable robots crawled across a simulated surface of the moon in search of water. One rover even looks a bit like WALL-E.

The excursion is not for entertainment, however. It’s a recent simulation at DLR (the German space agency) trying to help future Artemis astronaut moon missions with the search for water ice.

Astronauts need water for living, cooking and rocket fuel. The less water they can bring with them from Earth, the easier it will be to save on cost during launch — where every pound counts. And if machines can spot the H2O ahead of time, that will save valuable astronaut time for other goals.

Lightweight Rover Unit 1 — or LRU1, the machine that looks a little like WALL-E — mapped the simulated moon surface at the Luna Analog Facility in Cologne. The panoramic camera on its head allowed the rover to "see" both in visual wavelengths (what astronauts can see with unassisted eyes) as well as wavelengths beyond human vision, allowing it to scout for minerals or ice.

LRU1 also tugged a trailer with ground-penetrating radar on it to get a picture of the subsurface. Meanwhile, machine LRU2 followed its partner's lead. Then, after learning where to go, LRU2 did a pew-pew: It used a robotic arm and a laser to do spectroscopy, or mapping patterns of light, to analyze rock samples. Because water has been found in lunar rock before, embedded in crystals of volcanic glass or mineral grains, lasering promising boulders may prove important.

DLR says working in tough conditions on the moon requires mobility, and that's why two rovers are involved. "The combination of different methods offers advantages" in learning about the surface and what lies below, according to a statement from Nicole Schmitz, a planetary scientist from the DLR Institute of Space Research. And this mission, which was the first prove-out of the tech provided by several participating entities, showed "all the elements are working," she added.

Schmitz led the Polar Explorer campaign in which the rovers were involved, along with the facility team. And the initial results are promising: the rovers found the water ice astronauts needed. Now, scientists are checking out the data in more detail to see what can be done for the next round of practice. Researchers can add the info from this round of testing to another one in which the rovers crawled up Mount Etna volcano in 2022.

The new Luna mission included some challenging hotspots, including a mock lava cave. Prospecting also had difficulties: Some water was only revealed through a (prearranged) network of seismic cables running across regolith piled nine feet (three meters) deep. The water's signal popped up after an artificial seismic source generated a mini moonquake, which created vibrations revealing the H2O.

While there's no firm flight date for this rover team, representatives hope Polar Explorer will be selected for a future Argonaut lander mission. Argonaut is named after the famed argonauts of ancient Greek mythology, who sailed in the ship Argo in search of an artifact to restore their leader, Jason, to his rightful kingship.

The moon-sailing Argonaut is a lander concept from the European Space Agency (ESA), of which DLR is a part. ESA officials hope to launch the first Argonaut mission as soon as 2031 in support of Artemis, by hauling tech for navigation, energy and telecommunications lunarside.