Apart from remodelling their home, astronauts on board the International Space Station are installing a new piece of equipment that may save their lives one day. Or embarrass them. It can go either way: Containing 32 sensors in a device the size of a shoebox, the ENose–or electronic nose–will be able to detect even the most subtle inorganic and organic smells. Like Carl Walz, ISS astronaut and Director for NASA’s Advanced Capabilities puts it, “having experienced an air-quality event during my Expedition 4 mission on the space station, I wish I had the information that this ENose will provide future crews.” Yes Carl. Air-quality events are bad.
This component is vital for the safety of astronauts in space. Humans can tolerate some smells without noticing until it's too late to react. As Margaret A. Ryan, the principal researcher of the ENose project at NASA's Jet Propulsion Laboratory, puts it:
The ENose is a 'first-responder' that will alert crew members of possible contaminants in the air and also analyse and quantify targeted changes in cabin environment.
The ENose uses polymer films that react to different chemicals in the air by changing their electrical conductivity. It can analyse aerosols and vapours, as well as monitor chemical spills, and even send data to the JPL's ENose computer, which can do more complex analysis. It's extremely sensitive: Depending on the chemical, it can detect "fractional parts per million to 10,000 parts per million."
What is surprising is that the ENose is not yet a permanent part of the ISS. In fact, it's surprising that something like the ENose has never been a permanent part of any modern space mission except for the brief six-day demonstration that John Glenn did on STS-95, back in 1998. [JPL]