In the coming decades, NASA has big plans for Mars, including intentions to blast a fifth rover onto the planet’s surface by 2020 and send a manned mission by 2030.
But long before humans step onto Mars’ barren terrain, scientists and researchers from around the world want to understand more about its potential to support human life.
See also: The Stray Rover on the Far Side of Mars
They're especially interested in the possibility of growing plants on Mars, a more efficient process that would partially remove the need to ship expensive freeze-dried rations to the planet. Allowing crops to grow there that produce oxygen and scrub carbon dioxide there would make Mars a more livable environment.
“For a long-term settlement, there is probably no other option than growing food on Mars,” says Angelo Vermeulen, a Belgian artist and scientist who was the crew commander of the Hawaii Space Exploration Analog and Simulation Site (HI-SEAS), a six-person, NASA-funded team that spent four months last year on the hills of the Mauna Kea volcano in Hawaii to study and experiment with ways to prepare foods on Mars.

The HI-SEAS Habitat is on Hawaiian island Mauna Loa, at 8000 foot elevation in an abandoned quarry.
The HI-SEAS team selected Mauna Kea because they believe the mineralogy of its basaltic, volcanic soil is similar to that of Mars.
Vermeulen says one of the team's main concerns was combating what's known as "menu fatigue" in astronauts.
"It's a psychological phenomenon also found in the military that you develop when you eat the same foods over and over again," he tells Mashable. "After a while you start eating less and your physical condition goes down. The last thing you want is a skinny, underfed astronaut."
While the HI-SEAS team's primary research goal was to compare pre-packaged foods and meals astronauts could make with a limited supply of shelf-stable ingredients, members were also encouraged to devise their own studies on the Mars mock-up. Vermeulen chose to research food growth and remote-operated, robotic farming.
Along with Simon Engler, a scientific programmer specializing in robotics, Vermeulen set out to grow crops in a distant location that could not be readily accessed by the crew. To do so, he and Engler devised a spiral hydroponics garden system with a central robotic arm. Hydroponic growing, a process that utilizes mineral solutions in water without the need for soil, is preferable to growing plants in greenhouses on Mars because of diminished sunlight on the planet. (Mars receives just one-third of the amount of sunlight that Earth receives, and is susceptible to violent dust storms, which further compromises light intensity.)
Eventually, Vermeulen says, he was able to grow a host of crops, including arugula, two types of lettuce, two types of chard and spinach.
"The goal is to develop a system where robotics can take over part of the maintenance and food growing tasks, and, as such, free up time for the astronauts," he says.
Vermeulen also experimented with growing sprouts to give the HI-SEAS team a change of pace from shelf food. He used commercially available sprouting systems, built his own system by hacking plastic containers and even used a 3D-printed sprouting system, reflecting the resourcefulness and creativity required during a mission.
Eventually, Vermeulen adds, the sprouting project yielded alfalfa, broccoli, clover, radish and mung bean. He says the mung beans were used in a curry dish consumed by the astronauts, and the alfalfa were added to a sushi recipe.
The prospect of successful food growth on Mars is promising in part because plant waste there could be composted and mixed with Martian soil to make more effective crops, a similar process to what occurs in lava fields when plant species slowly colonize a basaltic landscape and lend their organic materials to it.
Ecologist Dr. Wieger Wamelink of the Alterra Institute in the Netherlands also recently studied the possibility of food growth on Mars. Wamelink planted seeds of 14 plants on artificial Martian soil provided by NASA and compared those crops to a control group that used soil from the nearby banks of the Rhine River.

Dr. Wieger Wamelink arranges pots of faux Mars and Moon soils.
Surprisingly, Wamelink says, all 14 plants species germinated in the Martian soil and many even outgrew their counterparts in the Rhine soil. Wamelink also observed that the Martian soil contained more nitrogen and held water better than he originally believed it would.
"The germination was quite good," he says. "Rye and cress germinated within 24 hours and after about a month, the rye, cress and a wild plant — field mustard — started growing flowers."
Wamelink says he was especially pleased that he was able to fertilize a few plants by hand with a brush. Eventually, he says, the cress and field mustard plants grew seeds, which is a welcome sign to ecologists hoping to reproduce plants in Martian soil.
If astronauts are able to continually grow fresh food on Mars through reproduction, it would bode well for them both physically and mentally — growing and then sharing food is a source of psychological well-being.
"You enjoy little gestures."