NASA working to make anti-radiation tiles from garbage
Published Saturday, January 5, 2013 7:00AM EST
Astronauts may soon be padding their living quarters with discarded food wrappers if a NASA project to make tiles out of garbage survives ongoing rounds of testing.
Developed by California’s Ames Research Centre -- a branch of the space agency -- the small, round tiles are made from the equivalent of a day’s space station garbage, compressed to one-tenth its original size in a high-heat compactor. The process melts the trash without setting it on fire, producing a tile with a 20-centimetre diameter that is just over one-centimetre thick, according to a post this week on NASA’s website.
The tiles contain “plastic water bottles, clothing scraps, duct tape and foil drink pouches… patched together in a single tile along with an amalgam of other materials left from a day of living in space,” states NASA.
Researchers at Florida’s Kennedy Space Center are now working to determine whether the tiles are safe to store on a spaceship, and if they could be used to protect astronauts from radiation -- a possibility due to the condensed plastic resulting from the garbage. Exposure to the sun’s radiation in space is believed to cause diseases like Alzheimer’s.
In the production process, the tiles are heated at temperatures between 150 and 175 degrees Celsius for about 3.5 hours. Microbiologist Mary Hummerick says that should be hot enough to kill any micro-organisms living on the garbage, but it’s possible that some bacteria could go inert instead of dying, growing back later.
For the tests, the tiles are being stored in matching conditions to those on the space station.
Using garbage to protect astronauts from radiation would fulfill two very important roles for astronauts on long-range trips, such as a Mars mission.
On such a trip -- which would take about two years -- space for waste would be extremely limited, and astronauts would face lengthy exposure to the high-radiation levels from outer space. The tiles could potentially be used to shield the astronauts’ sleeping quarters, or to build a radiation shelter within the spacecraft to protect crews from high-radiation events, such as solar flares.
Currently, astronauts on the International Space Station pack their waste into a capsule that burns up upon entry into earth’s atmosphere, but that won’t be an option on a mission to another planet, says Randy Attwood, Managing Editor of Space Quarterly Magazine.
“Everything they want to get rid of they put in these unmanned spacecraft,” he explained to CTV’s Canada AM on Friday. “They re-enter the atmosphere over the Pacific Ocean. They don’t have any heat shields and they burn up.”
Further, ejecting trash from a spaceship on a long-range mission would contravene NASA’s policy to avoid contaminating other planets or moons.
"We don't want to contaminate the surface of an asteroid or something just by throwing the trash out the door," said Richard Strayer, also a Kennedy-based microbiologist, in the NASA web post. "If NASA doesn't do something about it, then the spacecraft will become like a landfill, with the astronauts adding trash to it every day."
In fact, even the “space garbage pizzas,” as he calls them, may end up being too much extra material for the space station to handle, suggests Attwood.
“I’m not sure how practical this is,” he said. “They’re going to have to grow their own food and reuse everything they have… The saying on the space station is ‘yesterday’s coffee is tomorrow’s coffee.’”
Meanwhile, scientists are also examining whether water removed from the garbage could be repurposed by a space crew.
"The mindset is, with limited resources, whatever you can use, you want to be able to repurpose that," Hummerick suggests. "Water is a very valuable commodity, so you want to recover all of that you can."