Kerosene

The world's first flight test for an aerospike rocket engine ended in disaster, but Polaris Aerospace is back on track, preparing to fly second- and third-generation prototypes for its MIRA supersonic/hypersonic aircraft platform within weeks.

It was set to be the world's first flight test for an aerospike rocket engine, but the MIRA I prototype crashed on takeoff before the most innovative part of its propulsion system could fire. Undeterred, Polaris is building two bigger prototypes.

Engineers have demonstrated a pilot system that produces fuels from sunlight and air. The device captures carbon dioxide and water from the air and uses solar energy to convert it into syngas, which is then converted into carbon-neutral liquid fuels.

Using jet propellent and a combination of enzymes as catalysts, researchers at the University of Utah have produced a prototype fuel cell that runs at room temperature and without the need to ignite the fuel.