SpaceX's new engine, the Merlin 1D, has been qualified for spaceflight in advance of its first launch.

The engine, a heavily modified version of the Merlin 1C that powers SpaceX's standard Falcon 9, will be utilised on what SpaceX dubs the "Falcon 9 version 1.1", scheduled for its first launch in June. The Merlin series uses rocket propellant (RP-1) and liquid oxygen.

The Merlin 1D puts out 147,000lb (654kN) of thrust to the 1C's 110,000lb. Nine of the engines power the first stage, and a single vacuum-capable engine powers the upper stage.

"The Merlin 1D successfully performed every test throughout this extremely rigorous qualification program," says Elon Musk, SpaceX chief executive and chief designer. "With flight qualification now complete, we look forward to flying the first Merlin 1D engines on Falcon 9's flight six this year."

The tests saw the engine fire for a total of nearly 2,000s at its McGregor, Texas test stand, these including four trials at full flight power and duration lasting 185s.

Though it has not powered a space-ready vehicle, a modified Merlin 1D is used on the Grasshopper, a reusable technology test bed.

Source: Flight International