Editing Fuel efficiency (section)

===In microgravity===
How fuel combusts affects how much energy is produced. The [[National Aeronautics and Space Administration]] (NASA) has investigated fuel consumption in [[microgravity]].

The common distribution of a flame under normal gravity conditions depends on [[convection]], because soot tends to rise to the top of a flame, such as in a candle, making the flame yellow. In microgravity or [[zero gravity]], such as an environment in [[outer space]], convection no longer occurs, and the flame becomes [[sphere|spherical]], with a tendency to become more blue and more efficient. There are several possible explanations for this difference, of which the most likely one given is the hypothesis that the temperature is evenly distributed enough that soot is not formed and complete combustion occurs., National Aeronautics and Space Administration, April 2005. Experiments by NASA in microgravity reveal that [[diffusion flame]]s in microgravity allow more soot to be completely oxidised after they are produced than diffusion flames on Earth, because of a series of mechanisms that behaved differently in microgravity when compared to normal gravity conditions.[https://web.archive.org/web/20070312020123/http://microgravity.grc.nasa.gov/combustion/lsp/lsp1_results.htm LSP-1 experiment results], National Aeronautics and Space Administration, April 2005. [[Premixed flame]]s in microgravity burn at a much slower rate and more efficiently than even a candle on Earth, and last much longer.<ref>[http://microgravity.grc.nasa.gov/combustion/lsp/lsp1_results.htm SOFBAL-2 experiment results] {{webarchive|url=https://web.archive.org/web/20070312020123/http://microgravity.grc.nasa.gov/combustion/lsp/lsp1_results.htm |date=2007-03-12 }}, National Aeronautics and Space Administration, April 2005.</ref>