Aluminium ice for rocket propellant

Researchers in the US are developing a more environmentally friendly rocket propellant made of a frozen mixture of water and ‘nanoscale aluminium’ powder.

The propellant and could be manufactured on the moon, Mars and other water-bearing bodies.

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

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 2.7m-tall rocket. The vehicle reached an altitude of 396m over Purdue's Scholer farms.

The tiny size of the aluminium particles, which have a diameter of about 80nm, 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, said Timothée Pourpoint, a research assistant professor in the Purdue’s School of Aeronautics and Astronautics.