2009:
Nano-aluminum arrives
Aluminum already represents a small but critical part of many rocket fuels, including the propellants for the space shuttle's solid booster rockets and NASA's next generation Ares rockets. The metal's high ignition temperature of more than 6,920 degrees Fahrenheit forces exhaust gases out at high velocity to propel rockets upward.
ALICE squeezes even more out of the aluminum by using nano-scale particles with diameters of 80 nanometers, or 500 times smaller than the width of a human hair. Such tiny particles combust more rapidly than larger particles to give an additional kick, and may allow easier control over a rocket's thrust.
"The nano-scale aluminum is really key to making system work," said Timothee Pourpoint, a professor in the school of aeronautics and astronautics at Purdue. "Using only micron-sized aluminum powder and water ice would not have worked."
Researchers have tossed around theoretical calculations of using just aluminum and water for rocket propellant in the past. But the Purdue and Penn State teams took advantage of the relatively new nano-aluminum to translate the concepts into reality.
"There have certainly been previous research efforts with nano-aluminum and water," Son told SPACE.com. "This effort is the first time that anyone has actually launched a rocket."
New Rocket Fuel Mixes Ice and Metal
https://www.space.com/7429-rocket-fuel-mixes-ice-metal.html