Electronic Nose

“Onboard the space station, astronauts are surrounded by ammonia. It flows through pipes, carrying heat generated inside the station (by people and electronics) outside to space. Ammonia helps keep the station habitable.

But it’s also a poison. And if it leaks, the astronauts will need to know quickly. Ammonia becomes dangerous at a concentration of a few parts per million (ppm). Humans, though, can’t sense it until it reaches about 50 ppm.

Ammonia is just one of about forty or fifty compounds necessary on the shuttle and space station, which cannot be allowed to accumulate in a closed environment.

And then there’s fire. Before an electrical fire breaks out, increasing heat releases a variety of signature molecules. Humans can’t sense them either until concentrations become high.

Astronauts need better noses!

That’s why NASA is developing the Electronic Nose, or ENose for short. It’s a device that can learn to recognize almost any compound or combination of compounds. It can even be trained to distinguish between Pepsi and Coke. Like a human nose, the ENose is amazingly versatile, yet it’s much more sensitive.”