Mars came nearer to Earth this year than it has in more than 50,000 years, but a new technology could bring it closer still. Scientists have developed a fully sustainable disposal system to deal with waste on long-range space flights using a simple byproduct of wheat. Wheat grass, an inedible part of the wheat plant, can be used to reclaim pollutants produced from burning waste on a spaceship, according to researchers from Lawrence Berkeley National Laboratory and NASA. The wheat grass itself would normally be trash, but now it can be put to good use in a process that moves the space program one step closer to a manned mission to Mars.