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Spacecraft smoke detectors must detect different types of smoke. For
example, hydrocarbon fuels typically produce soot and plastics produce
droplets of recondensed polymer fragments. While paper and silicone
rubber produce smoke comprised of liquid droplets of recondensed
pyrolysis products. Each of these materials produces a different
type of smoke, with particles of various sizes and properties.
SAME will assess the size and distribution of smoke particles produced
by different types of material found on spacecraft such as, Teflon,
Kapton, cellulose and silicone rubber. SAME will evaluate the performance
of the ionization smoke detectors (used on Space Shuttles), evaluate
the performance of the photoelectric smoke detectors (used on the ISS)
and collect data for which a numerical formula can be developed and
used to predict smoke droplet growth and to evaluate alternative smoke
detection devices on future spacecraft.
Research Summary
Fire is commonly detected by measuring changes
in the amount of airborne microscopic particles (one of the components
of smoke).
Smoke detectors currently in use on ISS and Space Shuttle are
based on detectors used on Earth that detect different sizes of
smoke particles.
SAME will measure the distribution of particle sizes in smoke
from on-orbit combustion of several materials found in the spacecraft.
Testing will also examine the effects of sample temperature, air
flow and smoke residence time (near the source) on the particle
size distribution of the smoke.
Results will allow an evaluation of the performance in microgravity
of the two existing U.S. spacecraft smoke detector designs, in
use on the Shuttle and ISS, and evaluate other fire detection
devices.
Information from this experiment will improve the design requirements
for and reliability of smoke detectors on future spacecraft.
Space Applications
The SAME experiment will provide
technology for an advanced fire detector for future spacecraft that
will be used for long duration missions. SAME will provide quantitative
data on the sensitivity of these detectors to reduced gravity smokes
that will allow evaluation of the adequacy of these existing technologies
using relevant data. The current Fire Prevention, Detection, and
Suppression (FPDS) program plan allows for the re-evaluation of
future sensor technology, to allow new technology and capability
to be utilized. The results from SAME are needed to provide the
reduced gravity baseline data against which future detection technology
developments can be evaluated.
Earth Applications
The smoke detectors developed
from the results of SAME can also be useful in other extreme environments
on Earth, such as submarines or underwater laboratories. Accurate
detection of smoke in these environments can save lives. |
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SAME in
the Microgravity Science Glovebox |
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SAME photoelectric
detector |
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SAME ionization
detector |
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