One of the constant and most dangerous hazards
in space is the risk of fire. The three main aspects of fire safety
are prevention, detection, and suppression. Spacecraft are equipped
with smoke detectors, alarms, and warning lights so that fires can
be detected and prevented as soon as possible. Non-toxic portable
fire extinguishers, masks, and oxygen bottles can also be used in
case of fire. The atmosphere control system then removes toxic substances
from the air. Several projects are underway to make space travel as
safe from fire as possible.
Engineers and scientists have devoted a
large amount of time to preventing fires from occurring in a spacecraft.
The unique conditions and operating environment of a spacecraft require
a different approach to preventing fires. Because microgravity combustion
experiments indicate that fire can behave differently in space, the
best methods to handle them may differ from those used on Earth.
Although the common way to detect a fire is through smoke detectors, sensors that detect combustion or measure radiation or temperature changes are also used. Other methods include alarms and warning lights. In addition, the fire protection system may automatically release a fire suppressant. Non-toxic portable fire extinguishers (carbon dioxide-based), masks, and oxygen bottles are available in case a fire does occur. The atmosphere control system then filters the air to remove toxic substances.
The NASA Glenn Research Center has several ongoing research projects in fire safety. The three major areas being addressed are:
|- Fire prevention and material flammability
- Fire detection
- Fire suppression
The flammability of materials differs on Earth and in space. One material flammability project, Material Properties Governing Co-Current Flame Spread in Microgravity, evaluates the flammability of materials in low-gravity.
Smoke is made up of small particles with diameters between 0.1 - 0.5 microns. Because low-gravity smoke differs from normal gravity smoke, a fire detection project, Characterization of Smoke from Microgravity Fires for Improved Spacecraft Fire Detection, measures the size of smoke particles from different materials in order to optimize the sensitivity and efficacy of smoke detectors.
A fire suppression project, Secondary Fires:
Initiation and Extinguishment deals with a small fire that ignites
surrounding material to become a large fire. Objectives include
observing how easily nearby materials ignite and how effectively
carbon dioxide and other gases can extinguish fires in low gravity.
Spacecraft fire safety initiative research projects work to make the journey through space as safe as possible.