On January 16, 2007, a dazzling blue flame blasted across the sands of the Mojave desert. In many respects, it looked like an ordinary rocket engine test, but this was different. While most NASA rockets are powered by liquid oxygen and hydrogen or solid chemicals, “we were testing a methane engine,” says project manager Terri Tramel of NASA’s Marshall Space Flight Center (MSFC). The main engine, built and fired by the NASA contractor team Alliant Techsystems/XCOR Aerospace, is still in an early stage of development and isn’t ready for space. But if the technology proves itself, methane engines like this one could eventually be key to deep space exploration.
Methane (CH4), the principal component of natural gas, is abundant in the outer solar system. It can be harvested from Mars, Titan, Jupiter, and many other planets and moons. With fuel waiting at the destination, a rocket leaving Earth wouldn’t have to carry so much propellant, reducing the cost of a mission.