Today, SpaceX released the following statement:
Approximately one minute and 19 seconds into last night’s launch, the Falcon 9 rocket detected an anomaly on one first stage engine. Initial data suggests that one of the rocket’s nine Merlin engines, Engine 1, lost pressure suddenly and an engine shutdown command was issued immediately.
We know the engine did not explode, because we continued to receive data from it. Our review indicates that the fairing that protects the engine from aerodynamic loads ruptured due to the engine pressure release, and that none of Falcon 9’s other eight engines were impacted by this event.
As designed, the flight computer then recomputed a new ascent profile in real time to ensure Dragon’s entry into orbit for subsequent rendezvous and berthing with the ISS. This was achieved, and there was no effect on Dragon or the cargo resupply mission.
An update has been released, and the second sentence of the second paragraph now reads: “Panels designed to relieve pressure within the engine bay were ejected to protect the stage and other engines. Our review of flight data indicates that neither the rocket stage nor any of the other eight engines were negatively affected by this event.”
The current, complete press release is here.
Information on Pintle Injector Rocket Engines is here.
At left below is an image of the Falcon 9 and the nine Merlin 1C engines. Each corner engine is protected by the triangular fairing.
The image on the right shows the engine fairing (dark, triangular object) tumbling behind the engine compartment.