Merlin engine testing
The Falcon 9 rocket, which SpaceX is scheduled to launch, is powered by the Merlin engine SpaceX

On Saturday (4 November), one of SpaceX's next-gen rocket engines exploded during a test at the company's facility in McGregor, Texas.

The explosion, first reported by the Washington Post, happened during a "qualification test" of a new Merlin engine, which is supposed to be used in Falcon 9 rockets in late 2018.

According to a source cited by Ars Technica, the incident happened during a procedure called LOX drop in which liquid oxygen fuel is filled in the engine to check for leaks. And before the rocket engine could even fire up, the liquid oxygen in it ignited -- due to a reason still unknown -- and triggered the explosion.

"No one was injured and all safety protocols were followed during the time of this incident," the company said in a statement. "We are now conducting a thorough and fully transparent investigation of the root cause."

The spacefaring giant further added it doesn't see any change in its current launch schedule as a result of this explosion.

The engine that exploded hasn't flown and was for the next-gen Block 5 version of the Falcon 9, which will likely carry improved thrust and landing capabilities, according to The Verge. However, until that version of the engine clears all the mandatory tests, the company plans on using an earlier Merlin engine in the Block 4 variant of the rocket scheduled to fly this year as well as in the first few months of 2018.

SpaceX has had a record run this with as many as 16 successful missions, most ever done by the company in a year. It has even landed 13 of those rockets safely back to Earth.

As for now, the company will suspend the testing of Block 5 engine, while investigating what caused the explosion and continuing with the tests for the Block 4 engine. Out of the two bays of the testing stand that sustained damage during the explosion, one will take at least a couple of weeks to be repaired, while the second will be repaired in a few days.

SpaceX has a few more missions lined up for this year – three Falcon 9 launches and finally the launch of Falcon Heavy with its 27 first stage engines.