A Merlin rocket engine exploded Sunday at SpaceX’s test facilities in Central Texas. According to the company, no one was injured in the accident, which damaged two bays in a Merlin engine test stand at the MacGregor facility.
“All safety protocols were followed during this incident,” said a company spokesman John Taylor. “We are now conducting a thorough and fully transparent investigation into the cause. SpaceX is committed to our current manifesto and we do not expect it to have any impact on our launch cadence.”
SpaceX is confident in its launch manifesto — the company plans to launch three or four more missions in 2017 — because the Merlin engine lost Sunday is being developed for the Block 5 version of its Falcon 9 rocket. All launches this year (and during the first few months of 2018) are scheduled to fly on the Block 4 variant of the rocket, which uses an earlier Merlin engine.
The company has three engine test benches at MacGregor: one for Merlin engines, one for the newer, more powerful Raptor engine, and another for upper stage engines. The Merlin test stand has two compartments, and while one compartment takes up to four weeks to repair, the other compartment should be ready for use in a few days. This allows the company to proceed with the “acceptance test” for its Block 4 Merlin engines, the penultimate test before a missile is assembled, shipped to the launch site, and the entire booster undergoes a static fire test on the launch pad.
Sunday’s explosion, which was first reported by The Washington Post, took place before the engine was lit, a source told Ars. It happened during a procedure known as LOX drop, which involves adding liquid oxygen to the engine to determine if there are any leaks. At that moment, something caused the fluids in the rocket motor to explode. Testing of the Block 5 Merlin engine is suspended until the cause of that ignition is found and corrected.
SpaceX owes a lot to its Block 5 variant of the rocket, which company founder Elon Musk has said will improve the rocket’s performance and optimize reusability and power for rapid turnaround. This version of the rocket will also be used for commercial crew flights, carrying astronauts to the International Space Station for NASA. The company hasn’t announced a target date for the first flight of the Block 5 rocket, but it’s expected in 2018. It’s not yet clear how much Sunday’s engine explosion will delay that debut, if at all.