SpaceX announced on Wednesday March 20 that its next-generation rocket engine, the Merlin 1D, is ready for launch and will most likely power a commercial space flight this summer.

In order to qualify for launch, the engine was placed through 28 separate tests lasting almost 33 minutes at SpaceX's rocket-development facility in McGregor, Texas.  SpaceX plans to use the engine for its Falcon 9 rocket.

"The Merlin 1D successfully performed every test throughout this extremely rigorous qualification program," said SpaceX CEO Elon Must in a statement. "With flight qualification now complete, we look forward to flying the first Merlin 1D engines on Falcon 9's Flight 6 this year."

So far, the Falcon 9 has been operating off nine Merlin 1C engines. SpaceX expects the 1D to mark a significant improvement over the older model. It packs 147,000 pounds of thrust, compared with the 1C's 110,000 pounds. Nine engines power the first stage, while one engine powers the upper stage.

"The Merlin 1D has a vacuum thrust-to-weight ratio exceeding 150, the best of any liquid rocket engine in history," SpaceX stated in a press release. "This enhanced design makes the Merlin 1D the most efficient booster engine ever built, while still maintaining the structural and thermal safety margins needed to carry astronauts."

SpaceX already uses the Merlin 1D to power its Grasshopper rocket, a reusable test rocket capable of landing on Earth in one piece. The rocket achieved a record height during a test launch earlier this month. For future purposes, the company intends to use the engine to launch astronauts into space. In fact, one of its projects is a manned version of the Falcon 9/ Dragon capsule transportation system, which we saw arrive at the International Space Station on March 3. This would help SpaceX score a contract with NASA to transport astronauts back and forth from the station.

And as if that weren't enough, SpaceX plans to incorporate the engine into a huge rocket called the Falcon Heavy. Reportedly capable of carrying 53 tons of cargo to low-Earth orbit, the Falcon Heavy will use 27 engines during its first stage.

The SpaceX Dragon capsule is scheduled to depart its roughly three-week stay at the International Space Station on Monday March 25. It should land in the Pacific Ocean off the coast of Baja California at around 1:20 p.m. EDT.