Humans have unfortunately not yet evolved the ability to photosynthesize or recharge from an electricity source, which is why astronauts well into the future of spaceflight will need to have access to food sources. Developing ways to grow food in space is the focus of the new Deep Space Food Challenge that was just launched by NASA and Canada’s Space Agency (CSA).
With a total of twenty $25,000 USD prizes for US contestants and ten $30,000 CAD prizes for the Canucks in Phase 1 of the challenge, there’s some financial incentive as well. In Phase 2, the winning teams of the concept phase have to show off their kitchen skills, and in the final Phase 3 (deadline by Fall 2023) the full food growing system has to be demonstrated.
The possible systems here would likely involve some kind of hydroponics, aeroponics or even aquaponics, to save the weight of lugging kilograms of soil into space. None of this is truly new technology, but cramming it into a package that would be able to supply a crew of four with enough food during a three-year mission does seem fairly challenging.
The NASA rules are covered in their Phase 1 Rules PDF document. While international teams are also welcome to compete, they cannot receive any prizes beyond recognition, and Chinese citizens or companies with links to China are not to allowed to compete at all.