As Nasa talks more about the growing possibility of a manned mission to Mars and beyond, the challenges of feeding astronauts in missions that last months or even years become more and more pressing.
The space agency is attempting to find a solution to this problem, in awarding a $200,000 (£127,600) a year grant to a project aimed at creating a 'closed loop' system on a spacecraft - one that could use astronauts' waste into food, fertiliser, supplements or other useful materials for a long space flight.
The project that won the grant is called 'Synthetic Biology for Recycling Human Waste into Food, Nutraceuticals, and Materials: Closing the Loop for Long-Term Space Travel', and is led by Mark Blenner of Clemson University, South Carolina.
It will receive up to $200,000 a year for a maximum of three years, as Nasa tries to solve the problem of feeding humans for months in a cramped and inhospitable spacecraft.
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The issue of how to deal with space waste has long been a problem for Nasa, particularly when it comes to disposal, hygiene, and the sheer practicalities of going to the toilet in zero gravity.
For the Soviet Union, frozen urine that was vented into space from the Mir space station's toilet was hitting the station's solar panels and damaging them.
By 'closing the loop', spacecraft will be able to become much more self-sufficient, and ultimately will become more capable of taking long journeys, to Mars and even further.
