Wednesday, SpaceX conducted a full length test firing of the new Merlin 1D rocket engine at their test facility in McGregor, Texas.
Merlin 1D is the fifth version in the Merlin 1 series, all of which have been built in-house at their manufacturing facility in Hawthorne, California. The first generation Merlin flew on several Falcon 1 missions. The Merlin 1B never flew, and the Merlin 1C flew a couple of Falcon 1 flights before being superseded by the Merlin Vacuum in 2009, which has powered all the Falcon 9 rockets.
The Merlin 1D produces 147,000 pounds of thrust (55% more than the Merlin Vacuum) and burned for 185 seconds, simulating a complete Falcon 9 first stage launch.
The Merlin 1D engines will first see flight on Falcon 9 Flight 6, expected to launch in 2013.