It sounded like an immature April Fool's joke, but it wasn't. NASA really did want researchers at the University of Florida to figure out a way to turn human excrement into rocket fuel. So Pratap Pullammanappallil and his colleagues complied.

Fast forward a few years, and Pullammanappallil's research team has found a solution -- a process that converts human waste into rocket-powering methane fuel.

Everybody poops -- even astronauts. But as of now, the bodily byproducts of astronauts are simply stored and dispatched to burn up in Earth's atmosphere upon re-entry. It's a perfectly fine solution for now, but by 2024, NASA expects to have an operating base on the moon that will serve as the launching point for future deep space missions.

Because they can't dump human waste on the moon, and because it would expensive and wasteful to launch it back toward Earth, NASA wants a way to repurpose the poo.

First, Pullammanappallil and his colleagues ran the numbers.

"We were trying to find out how much methane can be produced from uneaten food, food packaging and human waste," Pullammanappallil, an associate professor of agricultural and biological engineering at Florida, explained in a press release.

Their calculations suggested the endeavor was feasible. They estimated they could convert as much as 290 liters of methane per crew per day. Next, they came up with an conversion process using an anaerobic digester. The process produces a biogas -- a combination of methane and CO2 -- while killing off harmful pathogens in the waste.

"Methane can be used to fuel the rockets," Pullammanappallil said. "Enough methane can be produced to come back from the moon."

The process is detailed in the latest issue of the Advances In Space Research.

While the process was intended to launch rockets, it could eventually power electric grids or heat homes here on Earth.

"It could be used on campus or around town, or anywhere, to convert waste into fuel," Pullammanappallil said.