Hawthorne, Calif.-based Space Exploration Technologies Corp.’s (SpaceX) upgraded Merlin 1D main-stage engine completed a full-duration firing and multiple restarts at target thrust and specific impulse levels during recent tests at SpaceX’s facility in McGregor, Texas, the company announced June 25 in press release.

SpaceX fired the liquid oxygen- and kerosene-fueled engine for 185 seconds at 147,000 pounds of thrust.

With nine Merlin 1Ds, the first stage of SpaceX’s Falcon 9 rocket will produce nearly 1.5 million pounds of thrust in a vacuum, SpaceX said in the release. The upgraded engines will see their first flight on Falcon 9’s sixth launch, currently targeted for 2013.