Is Human Poop the Ultimate Rocket Fuel?
Human waste has been a hassle for spaceflight since the dawn of the space age -- but now it could transform our push toward the final frontier. Continue reading →
Human waste has been a hassle for spaceflight since the dawn of the space age.
The technique of doing a number 2 in microgravity has come a long way from the complex task of "pooping in a bag" during the Apollo era, but space agencies are still lumbered with the unenviable task of storing human waste and returning it to Earth for safe disposal during a fiery reentry.
Now, researchers from the University of Florida have been asked by NASA to turn the ‘human waste problem' into an invaluable resource for the future of space exploration. But what use could poop possibly have in space? Well, it could be turned into rocket fuel and the potential spin-offs could transform how we use human waste on Earth, too.
In 2006, when NASA was planning to set up a long-duration presence on the moon's surface by 2024, the agency wanted to find a way of reducing the launch weight of a mission from Earth and, in the process, to find something useful for the solid waste to do. Launching all that waste off the surface to return it to Earth seemed silly and disposing it in some secluded lunar crater was not an option.
Although NASA's lunar aspirations have been replaced by sending astronauts to an asteroid and then Mars, sidestepping the moon all together (a plan that has drawn more than its fair share of criticism, and for good reason), the University of Florida researchers have continued to seek out ways to make human waste more useful.
NASA sent the researchers a pre-packaged form of chemically-produced human waste that also included simulated food waste, towels, washcloths, clothing and packing material, according to a university press release. Then they got to work in an effort to see how much methane they could produce.
"We were trying to find out how much methane can be produced from uneaten food, food packaging and human waste," said Pratap Pullammanappallil, of the UF Institute of Food and Agricultural Sciences. "The idea was to see whether we could make enough fuel to launch rockets and not carry all the fuel and its weight from Earth for the return journey. Methane can be used to fuel the rockets. Enough methane can be produced to come back from the moon."
Pullammanappallil and graduate student Abhishek Dhoble then made the astonishing discovery that their laboratory process could extract 290 liters of methane from each crewmember of a hypothetical lunar astronaut per day.
To do this, they developed an "anaerobic digester process," which breaks down organic matter in the waste material, producing methane, carbon dioxide and a projected 200 gallons of non-potable (undrinkable) water annually. The process would also destroy the pathogens found in human waste. Through electrolysis, the researchers propose that the water can be broken down into oxygen and hydrogen - the oxygen could then be cycled into life support systems. In addition, the carbon dioxide and hydrogen may be converted into methane and water. Their laboratory process and the results have been published in the journal Advances in Space Research.
Like many techniques that are developed to advance us in space, this process has some very useful terrestrial applications - as populations grow, ever more innovative methods are needed to deal with human waste. Perhaps power stations driven by sewage could be the ultimate renewable energy resource of the future?
It seems that far from being a hindrance for the future of human spaceflight, poop may actually fuel our push to the final frontier while enriching life on Earth.
Source: University of Florida
The Russian Soyuz launch vehicle lifts off from Baikonur, Kazakhstan in 2012.
A Delta IV Heavy rocket lifts off from Cape Canaveral Air Force Station in Florida carrying NASA's Orion spacecraft on an unpiloted flight test to Earth orbit. Liftoff was at 7:05 a.m. EST.
The spacecraft on its way to its two-orbit, four-and-a-half hour mission high above and around Earth.
Astronauts on board the International Space Station watch the flight from their orbital perch.
An onboard camera offers a view of Space Launch Complex 37 just after launch.
A view during the separation of one of the Delta IV Heavy rocket boosters as it separates following liftoff.
An onboard camera captures separation of the three 13 by 14-foot Orion service module fairings following liftoff.
Orion's view of Earth from just under 3,000 miles above. That's just 600 miles shy of its peak altitude above Earth.
Earth -- as seen from Orion's pilot window at some 3,000 miles above Earth.
U.S. Navy ships stand ready to help recover Orion at the splashdown site in the Pacific.
Three main parachutes, measuring 116 feet in diameter each, help slow Orion's return to Earth.
The Orion crew module as it floats in the Pacific Ocean. Hopefully on a future flight, astronauts will be waiting to exit!