SpaceX’s Merlin 1D Reaches Crucial Milestone

SpaceX's Merlin 1D has completed the critical flight qualification phase and is now ready to be used on missions. Photo Credit: SpaceX
SpaceX’s Merlin 1D has completed the critical flight qualification phase and is now ready to be used on missions. Photo Credit: SpaceX

Space Exploration Technologies (SpaceX) has accomplished a major milestone toward having the Hawthorne, Calif.-based company’s Merlin 1D engine used on upcoming missions—flight qualification. During this program the Merlin 1D racked up a total of 1,970 seconds of test time in total. In essence, the 1D has achieved the same approximate amount of time as ten flights.

All total, SpaceX conducted some 28 tests of the Merlin 1D. However, four of these tests really put the 1D through its paces. In an effort to see just how much the Merlin 1D could take, the company pushed the engine’s capabilities to their limits.

According to a news release issued by SpaceX, during these four tests the new engine demonstrated a ratio of 4:1 for such determining factors as firing duration and restart capacity. According to SpaceX, the industry standard is 2:1. These four tests were designed to either meet or exceed both the power (147,000 pounds of thrust) and duration (185 seconds) of an actual Falcon 9 launch. With flight qualifications complete, the 1D is ready for use in SpaceX’s Falcon 9 launch vehicle.

SpaceX made sure to also test the Merlin 1D under conditions that exceeded what the engine would experience while conducting a mission. The tests were conducted at the company’s development facility, located in McGregor, Texas.

“The Merlin 1D successfully performed every test throughout this extremely rigorous qualification program,” said Elon Musk, SpaceX CEO and chief designer. “With flight qualification now complete, we look forward to flying the first Merlin 1D engines on Falcon 9’s Flight 6 this year.”

The Merlin 1D is the latest iteration of the engine that has powered five Falcon 9 rockets to orbit. Three of these launches have sent Dragon spacecraft to the orbiting International Space Station. The Falcon 9 uses nine (hence the “9” in Falcon 9) Merlins in its first stage. The Merlins impart almost 1.5 million pounds of thrust (in a vacuum).

According to SpaceX President Gwynne Shotwell, the Merlin 1D will be used on all future flights of the Falcon 9. The next launch is slated to take place from Vandenberg Air Force Base (the first Falcon 9 launch from this location) this June.


  1. Does anyone know was this part of the new reuseability program at SpaceX??? Could these engines be reused or are they a step in that direction?

    • The Grasshopper test rocket has been flying with a Merlin 1D, but I haven’t seen anyone mention if it’s the same engine or if they’re replacing it after each test.

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