January 3, 2013
Astronaut Space Trash Is A Spaceship Treasure
Lee Rannals for redOrbit.com — Your Universe Online
Researchers at NASA are evaluating tiles made of space trash to determine whether they can be used as radiation shielding during a deep-space mission.The tiles were produced at NASA's Ames Research Center in California, where engineers developed and built a compactor that melts trash but doesn't incinerate it.
Once the space trash is compacted, the garbage can become 8-inch diameter tiles about half an inch thick, NASA says. The tiles are constructed with plastic water bottles, clothing scraps, duct tape and foil drink pouches, along with an amalgam of other materials left from a day of living in space.
"One of the ways these discs could be re-used is as a radiation shield because there's a lot of plastic packaging in the trash. The idea is to make these tiles, and, if the plastic components are high enough, they could actually shield radiation," Mary Hummerick, a QinetiQ North America microbiologist at Kennedy working on the project, said in a statement.
The tiles could be placed in astronauts' sleeping quarters, or in a small area in the spacecraft that would serve as a storm shelter to protect crews from solar flare effects.
NASA scientists working in the Space Life Sciences Lab at Kennedy Space Center are trying to identify if the tiles are free of microorganisms or at least safe enough for astronauts to come into contact with daily.
The trash compactor heats up the garbage for 3 1/2 hours between 300 and 350 degrees Fahrenheit, which is hot enough to kill off any microorganisms. The device also squeezes a pound of material into the compressed tile, reducing the object 10 times its original size.
"Hopefully we achieve sterilization within the tile," Hummerick said. "We're starting a series of tests with a certain process temperature and time. We just sent Ames six bundles of our special trash recipe. They'll compact it and send them back to us for analysis. If the time and temperature tests seem to be achieving what we want, we'll go to long-range storage testing."
Tiles are stored in an atmosphere identical to that found in the International Space Station for testing. The microbiologists at NASA take small samples from the tile and look for signs of microbial growth. They are also looking to see if the tiles will support the growth of fungi and other micro-organisms if exposed to the conditions inside a spacecraft.
Handling trash on space missions is important to NASA because resources will be extremely limited for a crew that will be expected to live in space for up to two years.
Crews cannot just send the trash out into space because it could land on a planet or moon and possibly contaminate it, which is against NASA's policies.
"We don't want to contaminate the surface of an asteroid or something just by throwing the trash out the door," Richard Strayer, also a Kennedy-based microbiologist with Enterprise Advisory Services Inc, said. "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."
Hummerick said that another use for the trash would be to see if astronauts could remove water from it so it can be re-used by the crew.
"The mindset is, with limited resources, whatever you can use, you want to be able to repurpose that," Hummerick said in the statement. "Water is a very valuable commodity, so you want to recover all of that you can." In addition, the very low water content after compaction makes the tiles less likely to support any microbial growth.