Gadrev

The XCOR Aerospace begins test firing of Methane Rocket Engine – the 5M15 engine. The liquid methane and liquid oxygen is used as propellants. XCOR and ATK are developing the initial workhorse version of the 7,500 lbf LOX/methane engine for NASA. This regeneratively-cooled version of the rocket engine will also be built and tested in 2007 as part of the contract. ATK will use the workhorse engine as a basis for the design of the prototype version of the engine that will be closer to flight weight.

Source: XCOR press release