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. Spacecrafts 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.
Analysis
Engineers and scientists have devoted a large amount of time to prevent 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 effective carbon dioxide and other gases are at extinguishing fires in low gravity.
Spacecraft fire safety initiative research projects work to make the journey through space as safe as possible.