Monday, January 14th, 2013
Along with the complex calculations we call rocket science that NASA are must make to send a manned flight to Mars, there are other less glamorous yet still very important problems to be solved. For example: What can be done with two years worth of plastic and other trash created on a manned Mars flight so the spacecraft doesn’t become an interplanetary landfill?
Astronauts can’t just dump PET water bottles, food and drink pouches, and scraps of clothing and duct tape into space. It would pollute other planets, and in any case, it’s against NASA policy. One alternative could be repurposing the trash; therefore NASA researchers at the Kennedy Space Center in Florida have begun evaluating small tiles made of compacted space trash (see photo) to learn if they can be stored safely on a spacecraft.
They are also determining if the tiles can be used during a deep-space mission as radiation shielding, for example in crew sleeping quarters or in an area created as a storm shelter to protect the crew from solar flare effects. A critical factor for this use is how much plastic is in the trash — for radiation shielding, the more plastics the better.
The circular trash tiles being evaluated were made at NASA’s Ames Research Center in California, using a compactor that melts but does not incinerate the trash. Measuring eight inches in diameter and about half an inch thick, one tile contains a pound of trash compacted to at least one-tenth its original volume.
Besides their radiation shielding ability, the tiles are being tested for sterility. They are stored in an atmosphere identical to that of the International Space Station and samples are taken periodically and tested for signs of microbial growth. The microbiologists also want to know if the tiles can support growth of fungi or other microorganisms, despite the 300º to 350ºF heat of the compaction process.
Plastics have been widely used in the aerospace sector for some time, and now it seems possible that used plastics, along with other trash, could be repurposed to play a critical role in a manned Mars flight. There’s more info on how NASA is dealing with trash produced in space in this Plastics News article .