NASA builds a nose for bad news

While space shuttle astronauts are busy tending to their duties and scientific

experiments, NASA can smell trouble 250 miles away.

An electronic nose that uses computers and specialized sensing film

to work much like a human nose is being tested by researchers at NASA's

Jet Propulsion Laboratory as a way to detect unsafe chemical levels on the

International Space Station.

After a space shuttle flight in October 1999 successfully demonstrated

the technology, called E-Nose, researchers at JPL and the California Institute

of Technology began working to expand its sensitivity and shrink its size.

Amy Ryan, principal investigator for E-Nose at JPL, said the instrument

could be an event monitor on the International Space Station to alert the

crew if there is a spill or leak. "There's a lot of room on the space station,"

Ryan said. "The more automated you can make this kind of thing, the better

off the crew is."

Ultimately, E-Nose will identify an unsafe element in the air and send

a signal to the space station's environmental control system, and a central

computer will decide how to react, she said.

Nathan Lewis, a professor at Caltech, designed the E-Nose sensing films,

and NASA designed the instrument's hardware and associated processing software.

NASA adopted a commercially available Hewlett-Packard Co. handheld for E-Nose.

The instrument also has a sampling chamber and air filters, and NASA designed

the data acquisition system and wrote data analysis software.

NASA has been developing E-Nose for about four years, but the concept

of an electronic nose has been around for about 20 years, Ryan said. It

has taken off in the commercial market as well, with Cyrano Sciences Inc.

offering Cyranose 320, a product built around the Caltech sensing films,

primarily to the food and petrochemical industries.

Scientists at JPL are beginning to talk to other NASA departments and

other agencies about new applications for E-Nose, Ryan said. The Environmental

Protection Agency and defense agencies would be prime candidates, she said.

E-Nose has been identified as a possible environmental monitor in aircraft

cabins and on submarines, as well as in the oil, gas and food industries.

The size will be easy to condense, Ryan said. The E-Nose NASA used on the

shuttle is the size of a large paperback book and weighs about 3 pounds.

Ultimately, it could be the size of a tennis ball, she said.

Much like the human nose, E-Nose's sensors identify smell based on patterns

that it already recognizes. "Part of the power is the ability to train it,"

Ryan said.

The E-Nose software has been trained to recognize 12 scents, and scientists

are planning to train it to identify 20 to 30 common contaminants. It is

also trained to detect contaminants based on the maximum level to which

astronauts can be exposed for one hour. Ryan said she hopes to expand that

capability to the maximum level of exposure for 24 hours. For example, astronauts

can be exposed to 30 parts per million molecules of ammonia for one hour

but 20 parts per million of ammonia for 24 hours.

"What we envision...is several [units] distributed on the space station

connected to a central computer, which will take the data and control the

environmental controls," Ryan said.

Cyrano, meanwhile, has not begun to pursue applications outside the

food and beverage and petro- chemical industries, but Rick Sill, Cyrano's

vice president of sales and marketing, said he envisions markets in government

agencies and private industry for detection of narcotics, explosives and

land mines.

The Cyranose product is a handheld and sells for about $8,000. Cyrano

is also working with Welch Allyn Inc., a medical instrumentation firm, to

develop sensing technology that could detect cancers and ulcers based on

changes in the makeup of breath.