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UNDERSTANDING FIRE THROUGH IMPROVED TECHNOLOGY
PUBLIC SAFETY
ORIGINATING TECHNOLOGY/ NASA CONTRIBUTION
By studying fire through the science of combustion
physics, scientists and researchers from NASA, academia,
and private industry find new ways to improve fire
safety and increase fuel efficiency. Since gravity’s
effect on fire masks many details that occur during
the combustion process, scientists can gain a better
understanding of fire by studying it in microgravity.
Researchers from NASA’s Microgravity Combustion pro
gram at Glenn Research Center use drop towers, which
are long, vertical shafts, to study how fire behaves
in microgravity. Experiment packages are dropped from
the top of the tower, enabling them to achieve microgravity
through freefall. As part of their work to measure
fire behaviors, the NASA researchers needed a laser
capable of high sensitivity trace gas detection at
unique wavelengths. While diode lasers are suitable
for tests in the drop towers because they are rugged,
small, and low power, existing laser models did not
have the capability to produce the necessary range
of wavelengths.
PARTNERSHIP
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| The Aztec™ laser’s detection capabilities may lead to improved fire safety both
on Earth and aboard the Space Shuttle. |
NASA granted Southwest Sciences, Inc., of Santa Fe,
New Mexico, a Phase II Small Business Innovation Research
(SBIR) contract to develop a diode laser that could
meet the Microgravity Combustion program’s very specific
measurement requirements. As a result, the company
developed a broadly tunable external cavity diode laser
that offers unprecedented wavelength agility and tuning
speed.
Although the Aztec laser is not the first external
cavity diode laser, its increased capabilities mark
a tremendous leap in the technology. Dr. Nancy Piltch,
a NASA optical physicist for the Microgravity Combustion
program, described the technology advance as “equivalent
to switching from mechanical to electronic tuning.”
PRODUCT OUTCOME
Aztec™ is the commercial name for Southwest Sciences’
laser. The laser has coarse tuning ranges of 10 nanometers
(nm) to 30 nm at wavelengths ranging from 630 nm to
2,300 nm, making it the only commercially available
external cavity diode laser with wavelengths beyond
1,650 nm. The laser’s high-speed tuning in both coarse
and fine wavelength regimes allows for increased trace
gas detection. With the automated coarse tuning option,
the Aztec sweeps through its wavelength range in less
than 1 millisecond. While some diode lasers can only
detect one type, or species, of a trace gas, the Aztec’s
broad wavelength tuning provides access to multiple
trace gas species.
The Aztec has a wide range of applications for both
NASA and commercial users, from protecting astronauts
in space to improving combustion processes on Earth.
It may serve as a new tool for planetary exploration,
as it can detect a wide range of multiple gas species
in planetary atmospheres. The laser could optically
detect gaseous indicators of incipient fires on the
International Space Station and Space Shuttle, as well
as detect low concentrations of potentially toxic gases
in spacecraft crew habitats. The laser could also provide
more accurate fire detection in aircraft cargo compartments.
Since the Aztec can detect several gases that only
evolve during an actual fire, its implementation could
reduce the large number of commercial aircraft landings
that currently occur due to false alarms. Other applications
include environmental and industrial process monitoring.
Aztec™ is a trademark of Southwest Sciences, Inc.
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