NASA is gearing up for a planned manned mission to Mars some time in the 2030s, but before we can reasonably send people to another planet and expect them to fare well, there are some kinks that will need to be worked out. For instance, what those people will eat.

One of the major barriers to long-term survival on the red planet is food. Astronauts aboard the International Space Station eat prepackaged food, brought up by regular resupply missions. On Mars, such a steady supply is unlikely. Instead, said Clara Moskowitz for Space last year, “The first humans to live on Mars might not identify as astronauts, but farmers.”

Astronauts will probably have to grow all of their own food, a daunting task. But before we can expect them to do that, scientists need to find out in food can grow on Mars at all.

With that in mind, NASA researchers have proposed an experiment to put a greenhouse on Mars in 2021, says Mike Wall for Space. Piggybacking on the launch of the agency's next Mars rover, the experiment, if approved, would see a tiny greenhouse—a bit smaller than your head—transported to Mars. Inside would be hundreds of seeds of thale cress, a small flowering plant.

Growing plants in Mars-like conditions is no simple feat, as NASA researchers found out in 2004. Aside from the radiation and the lack of gravity, plants are not accustomed to Mars' low atmospheric pressure. Life on Earth can survive a great many challenges, from the heat of the desert to the cold of the Arctic. But a lack of atmosphere is not something plants are used to dealing with. The only real way to know whether we can work around these challenges is to try.