Washington, Nov 20 : NASA astronauts on space shuttle Endeavour's STS-126 mission will install an instrument known as "ENose" on the International Space Station (ISS) that can help protect crew members' health and safety by "smelling" dangerous chemicals in the air.
The experimental ENose will monitor the space station's environment for harmful chemicals such as ammonia, mercury, methanol and formaldehyde.
The ENose, which will run continuously and autonomously, is the first instrument on the ISS that will detect and quantify chemical leaks or spills as they happen.
It fills the long-standing gap between onboard alarms and complex analytical instruments. Air-quality problems have occurred before on the International Space Station, space shuttle and Russian Space Station Mir.
"The ENose is a 'first-responder' that will alert crew members of possible contaminants in the air and also analyze and quantify targeted changes in the cabin environment," said Margaret A. Ryan, the principal investigator of the ENose project at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California.
Station crew members will unpack the ENose on December 9 to begin the instrument's six-month demonstration in the crew cabin.
If the experiment is successful, the ENose might be used in future space missions as part of an automated system to monitor and control astronauts' in-space environments.
"This ENose is a very capable instrument that will increase crew awareness of the state of their air quality," said Carl Walz, an astronaut and director of NASA's Advanced Capabilities Division.
Specifically, the shoebox-sized ENose contains an array of 32 sensors that can identify and quantify several organic and inorganic chemicals, including organic solvents and marker chemicals that signal the start of electrical fires. The ENose sensors are polymer films that change their electrical conductivity in response to different chemicals.
The pattern of the sensor array's response depends on the particular chemical types present in the air.
The instrument can analyze volatile aerosols and vapors, help monitor cleanup of chemical spills or leaks, and enable more intensive chemical analysis by collecting raw data and streaming it to a computer at JPL's ENose laboratory.
The instrument, which weighs less than nine pounds and requires only 20 watts of power, has a wide range of chemical sensitivity, from fractional parts per million to 10,000 parts per million.
It includes data-analysis software to identify and quantify the release of chemicals within 40 minutes of detection.
While it will look for 10 chemical types in this six-month experiment, ENose can be trained to detect many others.