Firefly Aerospace has confirmed that one of its Reaver engines shut down shortly after its Alpha rocket left the pad last week, resulting in the destruction of the vehicle in spectacular fashion just after reaching supersonic velocity.
In a sequence of tweets in which Firefly bravely asserted it had “arrived” as a company “capable of building and launching rockets” if not quite one that can deliver a payload to orbit, the team ticked off its achievements.
The rocket left the pad as planned: check. There was no unwanted tipping or rotation as it picked up speed: check. All four engines burned as planned: Well… kind of. For 15 seconds.
At around the 15-second mark, engine number two on the first stage performed what the company called “an uneventful shutdown.” Uneventful for the engine, maybe. Not so much for the rest of the mission, which continued with only three of the four engines running and a marked drop in the rate of climb.
Still, climb the rocket did, despite only three engines providing thrust vector control. However, things came unstuck as the rocket moved through transonic and into supersonic flight. The resulting tumble was clearly visible and sufficient for the range to explosively end the show. “The rocket did not explode on its own,” added Firefly.
As for why that engine shut down early, Firefly has kicked off an anomaly investigation. It said it would be trying again “as soon as possible.”
It took a good few seconds for the flight termination system to be triggered, during which time the payload fairing could be seen detaching as the booster tumbled. The rocket itself, however, remained intact despite the forces acting on it. Right up until the flight was terminated.
Still, the fact that the affected engine shut down cleanly will be of some comfort to Firefly’s engineers. The question now is: why? ®