By John Herrman
Posting in Energy
From waste to watts: Launching with high scientific hopes, the first UN satellite will waste no time getting down and dirty.
Part of the deal when you sign up to be an astronaut is that you're going to become better acquainted with human waste. Your own, specifically First there is the unavoidable, and unavoidably unpalatable, issue of using the bathroom in microgravity. Then there's the ever-so-slightly abstracted matter of recycling urine into drinking water.
The UNESCOSat research satellite, a $5m project of the UN, will carry a number of scientifically valuable payloads into space, including, according to Fast Company, one that is "intended to examine the effects of Shewanella MR-1 (a bacteria) in a microgravity environment to determine its suitability for long-term space travel."
A quick search reveals many things about this space-bound bacteria: it's an "interesting" organism; it's capable of aerobic and anaerobic reproduction; and it's useful in something called "metal reduction". The quality that the Florida Institute of Technology--the originator of this particular payload--is most interested in is something else entirely. From the USDA's Agriculture Research Project:
Interest in the production of hydrogen as an energy source has increased markedly in recent years in response to concerns over the high cost and limited supply of petroleum. Hydrogen can be produced by fermentation of a wide variety of agricultural materials, but current technologies suffer from low yields and productivity...
In the current research, the effects of aeration of the electro-active bacterium, Shewanella oneidensis, on current production, iron reduction, hydrogen production in a microbial electrolysis cell, and electric power generation in a microbial fuel cell were studied. The performance of aerated S. oneidensis was considerably enhanced compared to anaerobically grown cultures of the microbe.
When applied to a spacecraft, the phrase "agricultural materials" can only mean one thing: human waste. And indeed, the purpose of FIT's payload is to examine whether or not this bacteria, which is capable of efficiently producing large amounts of hydrogen from human waste on Earth, is able to reproduce consistently in an orbital environment.
If it proves resilient, the waste gas it produces from, well, waste, could be harnessed in hydrogen fuel cells, and used to enhance a spacecraft's overall energy efficiency.
The satellite won't launch until next year, and determining Shewanella MR-1's viability in microgravity is just one of many steps to be taken before a waste-fueled power plant can be installed on a manned space station. Should it work, though, the tightly contained energy systems that the modern astronaut lives in, and is a part of, will get just a bit tighter.
Image of the ISS's Zvezda toilet courtesy of NASA
Nov 18, 2010