scispace - formally typeset
Search or ask a question

Fire behavior and risk analysis in spacecraft

TL;DR: In this paper, the authors discuss the application of low-gravity combustion knowledge and appropriate aircraft analogies to fire detection, fire fighting, and fire-safety decisions for eventual fire-risk management and optimization in spacecraft.
Abstract: Practical risk management for present and future spacecraft, including space stations, involves the optimization of residual risks balanced by the spacecraft operational, technological, and economic limitations. Spacecraft fire safety is approached through three strategies, in order of risk: (1) control of fire-causing elements, through exclusion of flammable materials for example; (2) response to incipient fires through detection and alarm; and (3) recovery of normal conditions through extinguishment and cleanup. Present understanding of combustion in low gravity is that, compared to normal gravity behavior, fire hazards may be reduced by the absence of buoyant gas flows yet at the same time increased by ventilation flows and hot particle expulsion. This paper discusses the application of low-gravity combustion knowledge and appropriate aircraft analogies to fire detection, fire fighting, and fire-safety decisions for eventual fire-risk management and optimization in spacecraft.
Citations
More filters
Journal ArticleDOI
TL;DR: In this article, a two-dimensional, time-dependent model is developed describing ignition and the subsequent transition to flame spread over a thermally thin cellulosic sheet heated by external radiation in a microgravity environment.

41 citations

Journal ArticleDOI
TL;DR: In this paper, the scenario approach of risk assessment is used to identify modeling needs and, in turn, experiments that would aid in the development of models that would meet these needs.

16 citations

01 Oct 1989
TL;DR: A detailed review identifies spacecraft fire safety issues and the efforts for their resolution, particularly for the threats posed by the increased on-orbit duration, size, and complexity of the Space Station Freedom as discussed by the authors.
Abstract: A detailed review identifies spacecraft fire safety issues and the efforts for their resolution, particularly for the threats posed by the increased on-orbit duration, size, and complexity of the Space Station Freedom. Suggestions provided by a survey of Wyle consultants and outside fire safety experts were combined into 30 research and engineering projects. The projects were then prioritized with respect to urgency to meet Freedom design goals, status of enabling technology, cost, and so on, to yield 14 highest priority projects, described in terms of background, work breakdown structure, and schedule. These highest priority projects can be grouped into the thematic areas of fire detection, fire extinguishment, risk assessment, toxicology and human effects, and ground based testing. Recommendations for overall program management stress the need for NASA Headquarters and field center coordination, with information exchange through spacecraft fire safety oversight committees.

13 citations

01 Jan 1991
TL;DR: In this article, the features of low gravity combustion that affect spacecraft fire safety, and the issues in fire protection for Space Station Freedom that must be addressed eventually to provide effective and conservative fire protection systems are discussed.
Abstract: Current fire protection for spacecraft relies mainly on fire prevention through the use of nonflammable materials and strict storage controls of other materials. The Shuttle also has smoke detectors and fire extinguishers, using technology similar to aircraft practices. While experience has shown that the current fire protection is adequate, future improvements in fire safety technology to meet the challenges of long duration space missions, such as the Space Station Freedom, are essential. All spacecraft fire protection systems, however, must deal with the unusual combustion characteristics and operational problems in the low gravity environment. The features of low gravity combustion that affect spacecraft fire safety, and the issues in fire protection for Freedom that must be addressed eventually to provide effective and conservative fire protection systems are discussed.

10 citations

01 Dec 1990
TL;DR: In this article, the conceptual design and operation of a critical set of experiments expected to yield information on suppressants and on suppressant delivery systems under realistic spacecraft-fire conditions (smoldering).
Abstract: Defined and justified here are the conceptual design and operation of a critical set of experiments expected to yield information on suppressants and on suppressant delivery systems under realistic spacecraft-fire conditions (smoldering). Specific experiment parameters are provided on the solid fuel (carbon), oxidants (habitable spacecraft atmospheres), fuel/oxidant supply, mixing mode, and rate (quiescent and finite; ventilated and replenishable), ignition mode, event, and reignition tendency, fire-zone size, fire conditions, lifetime, and consequences (toxicity), suppressants (CO2, H2O, N2) and suppressant delivery systems, and diagnostics. Candidate suppressants were identified after an analysis of how reduced gravity alters combustion, and how these alterations may influence the modes, mechanisms, and capacities of terrestrial agents to suppress unwanted combustion, or fire. Preferred spacecraft suppression concepts included the local, near-quiescent application of a gas, vapor, or mist that has thermophysical fire-suppression activity and is chemically inert under terrestrial (normal gravity) combustion conditions. The scale, number, and duration (about 1 hour) of the proposed low-gravity experiments were estimated using data not only on the limitations imposed by spacecraft-carrier (Shuttle or Space Station Freedom) accommodations, but also data on the details and experience of standardized smolder-suppression experiments at normal gravity. Deliberately incorporated into the conceptual design was sufficient interchangeability for the prototype experimental package to fly either on Shuttle now or Freedom later. This flexibility is provided by the design concept of up to 25 modular fuel canisters within a containment vessel, which permits both integration into existing low-gravity in-space combustion experiments and simultaneous testing of separate experiments to conserve utilities and time.

9 citations

References
More filters
01 Dec 1987
TL;DR: In this article, a flame spreading over a thermally thin cellulose fuel was studied in a quiescent microgravity environment, and two different extinction limits were found in microgravity for the two thicknesses of fuel.
Abstract: A flame spreading over a thermally thin cellulose fuel was studied in a quiescent microgravity environment. Flame spread over two different fuel thicknesses was studied in ambient oxygen-nitrogen environments from the limiting oxygen concentration to 100 percent oxygen at 1 atm pressure. Comparative normal-gravity tests were also conducted. Gravity was found to play an important role in the mechanism of flame spread. In lower oxygen environments, the buoyant flow induced in normal gravity was found to accelerate the flame spread rate as compared to the microgravity flame spread rates. It was also found to stabilize the flame in oxidizer environments, where microgravity flames in a quiescent environment extinguish. In oxygen-rich environments, however, it was determined that gravity does not play an important role in the flame spread mechanism. Fuel thickness influences the flame spread rate in both normal gravity and microgravity. The flame spread rate varies inversely with fuel thickness in both normal gravity and in an oxygen-rich microgravity environment. In lower oxygen microgravity environments, however, the inverse relationship breaks down because finite-rate kinetics and heat losses become important. Two different extinction limits were found in microgravity for the two thicknesses of fuel. This is in contrast to the normal-gravity extinction limit, which was found to be independent of fuel thickness. In microgravity the flame is quenched because of excessive thermal losses, whereas in normal gravity the flame is extinguished by blowoff.

41 citations


Additional excerpts

  • ...The comparative flame-spreading tests of Andracchio and Aydelott (1970), confirmed in a different geometric configuration by Olson (1987), were performed under quiescent (no forced flow) condi- tions....

    [...]

Journal ArticleDOI

25 citations


"Fire behavior and risk analysis in ..." refers background in this paper

  • ...More unconventional is the recommendation of Huggett (1973) on the use of a breathable atmosphere in which at least part of the nitrogen is replaced by a high molar-heat-capacity diluent gas (sulfur hexafluoride, for example)....

    [...]

Book
27 Oct 2017

24 citations

Journal ArticleDOI
TL;DR: In this paper, the authors measured flammability limits, burning velocities, and minimum ignition energies under initially quiescent conditions for stoichiometric and fuel-lean methane-, ethane-, and propane-air mixtures containing varying concentrations of Halon 1301.

22 citations