SpaceX’s Falcon 9 rocket is now a crucial step closer to getting more efficient new engines. While the launch vehicle currently uses nine of the company’s Merlin engines, the next-generation Merlin 1D achieved flight certification earlier this week.
The qualification program involved the 1D being subjected to 28 Earth-based tests, throughout the course of which it racked up a total of 1,970 seconds of run time – according to SpaceX, that’s the equivalent of over ten full missions’ worth of use. In four of those tests, it ran at or above the power (147,000 foot-pounds/199,305 Nm of thrust) and duration (185 seconds) required for launch. Additionally, it was “tested at propellant inlet and operating conditions that were well outside the bounds of expected flight conditions.”
When nine of the engines are combined in the Falcon 9’s first stage, they should produce almost 1.5 million ft-lbs (2,033,727 Nm) of thrust in a vacuum – the same as the existing Merlin engines. SpaceX claims that the Merlin 1D is the most efficient booster engine ever made, however, with a record-breaking vacuum thrust-to-weight ratio of over 150. The 1D is also designed for easier manufacturability, via higher-efficiency building processes, more use of robotics in its construction, and fewer parts.