Biodiesel powers Atlas rocket engine

By Rob Coppinger

A vegetable-based diesel fuel has been used to power a Rocketdyne LR-101 engine originally designed as a vernier rocket for the General Dynamics/Convair Atlas missile.

Vernier rocket engines are used for roll and attitude control. Using liquid oxygen for both tests, the biodiesel (B-100) was compared by San Diego, California-based-fluid dynamics and product engineering specialist Flometrics with US Air Force-supplied RP-1 grade kerosene.

With a 6s burn, the B-100 was found to have an 820lb (3.64kN)-thrust compared with the RP-1's 840lb. The propellant's tanks were from fire extinguishers so the vernier engine could not be run at full pressure and thrust without overstressing the tanks. Flometrics concluded that the more viscous B-100 may have a reduced performance due to its larger droplet size.

"We took data on LOX pressure, fuel pressure and chamber pressure. The thrust is proportional to the chamber pressure so this gives us a way to measure thrust. Vegetable-based fuel opens up the possibility of growing oil-producing crops on Mars," says Flometrics managing director Steve Harrington.

The effectiveness of biodiesel as a regeneratively cooled jacket coolant was not evaluated. In a few weeks Flometrics plans to launch a B-100 fuelled rocket built originally for a US television show.

© Reed Business Information 2009