WASHINGTON - Researchers are developing a new type of rocket propellant made of a frozen mixture of water and “nanoscale aluminum” powder that is more environmentally friendly than conventional propellants and could be manufactured on the moon, Mars and other water-bearing bodies.

The aluminum-ice, or ALICE, propellant might be used to launch rockets into orbit and for long-distance space missions and also to generate hydrogen for fuel cells, according to Steven Son, an associate professor of mechanical engineering at Purdue University.

The tiny size of the aluminum particles, which have a diameter of about 80 nanometers, or billionths of a meter, is key to the propellant’s performance.

The nanoparticles combust more rapidly than larger particles and enable better control over the reaction and the rocket’s thrust, according to Timothee Pourpoint, a research assistant professor in the School of Aeronautics and Astronautics.

“It is considered a green propellant, producing essentially hydrogen gas and aluminum oxide,” Pourpoint said.

“In contrast, each space shuttle flight consumes about 773 tons of the oxidizer ammonium perchlorate in the solid booster rockets. About 230 tons of hydrochloric acid immediately appears in the exhaust from such flights,” he added.

ALICE provides thrust through a chemical reaction between water and aluminum.

As the aluminum ignites, water molecules provide oxygen and hydrogen to fuel the combustion until all of the powder is burned.

“ALICE might one day replace some liquid or solid propellants, and, when perfected, might have a higher performance than conventional propellants,” Pourpoint said.
It’s also extremely safe while frozen because it is difficult to accidentally ignite,” he added.

Purdue is working with NASA, the Air Force Office of Scientific Research and Pennsylvania State University to develop ALICE, which was used earlier this year to launch a 9-foot-tall rocket.

The vehicle reached an altitude of 1,300 feet over Purdue’s Scholer farms, about 10 miles from campus.

“It’s a proof of concept,” Son said. “It could be improved and turned into a practical propellant. Theoretically, it also could be manufactured in distant places like the moon or Mars instead of being transported at high cost,” he added. (ANI)