MOXIE is already on the Red Planet. It’s now time to test it out.

Humanity’s future on Mars may depend on a golden box about the size of a car battery.

On February 18, NASA’s Perseverance rover landed on Mars with this box, called MOXIE, nestled in its belly.

MOXIE was designed to convert carbon dioxide into oxygen on Mars, and NASA plans to put it to the test within the next few months. If it works as hoped, the instrument could play a key role in getting astronauts home from Mars — and maybe even help them survive while on the Red Planet.

NASA can’t send people to Mars until it knows it can also bring them back, and that means making sure the astronauts have enough rocket propellant for the return trip.

The most straightforward option is to send the propellant — a combination of oxygen and rocket fuel — to Mars with the astronauts.