16 JAN 2016

Space Salad

With the global population forecast to be almost ten billion by 2050, the idea of moving to Mars could catch on. But if this science-fiction fantasy does become reality, what sort of diet could the first settlers expect?

For decades, US space agency Nasa, and its partners have sent orbiters, rovers and landers to Mars to test whether it would be possible to live and work on the planet. NASA’s plan is to send humans to low-Mars orbit in the early 2030s.

Meanwhile, Silicon Valley entrepreneur Elon Musk believes he will have us treading the red planet by 2024. He is busy directing engineers at his rocket venture SpaceX to design the rockets to boldly get us there.

To succeed, however, we must also work out how to take care of other more mundane essentials, such as filling the interplanetary salad bar.

A steady supply of fresh produce will be vital in keeping the first Martian voyagers healthy and their morale high. “The shelf life of [packaged] foods may not be long enough for a Mars mission and some of the nutrients might degrade over time,” says Gioia Massa, a project scientist at NASA’s Kennedy Space Center in Florida, making the provision of fresh food a mission-critical ingredient in successful Mars missions.

Massa is the lead scientist for Naas’s Veggie team, a project that includes Wisconsin-based Orbital Technologies, a national leader in aerospace systems, Purdue University and Johnson Space Center. Veggie offers a working model for growing vegetables in space and the system has so far produced fresh romaine lettuce and Zinnia flowers using LED lights.

It will be a wonderful thing for everybody here on Earth as well because we are going to learn so much about how to live sustainably

- Dr Gioia Massa

The challenges of growing plants in space include ensuring they can grow in small spaces with a growth media suitable for their unusual environment. The plants were grown on “‘pillows” containing a growth media that includes controlled release fertilizer and a type of calcined clay used on baseball fields to increase aeration and encourage growth. “Veggie was designed to be very much an astronaut garden, so low mass, low volume, low power,” says Massa. “We have to be really productive.”

There is much research to be done however, to establish whether plants can thrive in the unique conditions of inter-planetary space such long-term exposure to cosmic radiation.

But there are also unique issues that will make it harder to produce food. “Without gravity you have no buoyancy, you have no convection, heat doesn't rise and fluids and gasses don’t mix well and that’s a challenge for plant growth,” says Massa. “It is pretty overwhelming. There are so many challenges that we have to overcome and like any area of science or technology development, you do one thing and it spawns ten new questions. There are just so many things we have to figure out.”

Answering such questions will also be vital to future long-term missions that stay on Mars. “The longer you stay on a place like Mars, you’ll want to grow more of your food,” she says. “So we just want to take these first steps for developing these food production systems.

“The plants will be doing other things too. They will be helping to recycle your atmosphere, clean your water and take care of your waste and you want to do that in ways that are sustainable.”

Working out what plants need in an ecosystem designed from scratch, including the complex colonies of and interactions between bacteria they may need to thrive, could offer new insights for farming on our own planet, too.

"It will be a wonderful thing for everybody here on Earth as well because we are going to learn so much about how to live sustainably as we try and develop this. I think that it’s going to benefit everyone."

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