SpaceX Falcon-9 FT with Israeli communication satellite Amos-6 belonging to Spacecom Ltd. exploded at Cape Canaveral before ultimate trial before launch planned for 3rd September at 07:00 GMT. This test fire was planned to be conducted at Complex 40 launch pad.
This accident happened over 14 months after failure CRS-7 mission on June 2015. This time Falcon-9 failed before fire test, last before launch scheduled for Saturday. Rocket was standing on launch pad at SLC-40 and was just in the end of the fueling procedure; tanks were filled with liquid oxygen and were full; ground service teams were finishing loading RP-1 propellant. Video recorded during fueling shows clearly that visible part of the explosion started in the upper section of the rocket, slightly under payload fairing covering Amos-6. Next, burning propellant sprays around launch tower and few seconds later whole fairing is falling to the ground. After explosion upper part of the launch tower is visibly broken and whole rocket is lying on the ground covered with smoke. Luckily, whole ground service team was far away from the rocket due the standard safety procedures during fueling and nobody was hurt. According to official statement given shortly after accident by SpaceX, place where fire started was identified:
"The anomaly originated around the upper stage oxygen tank and occurred during propellant loading of the vehicle. Per standard operating procedure, all personnel were clear of the pad and there were no injuries."
It seems that upper oxygen tank is weak point in Falcon-9 construction. During CRS-7 same tank started problems with rocket after 139 seconds of flight. It was caused by strut keeping helium valve in its position which failed; valve was no longer keeping Helium away from Oxygen in the second tank. This lead to increasing pressure inside tank, leakage and finally to explosion.
For the moment Company is not announcing any details about character of the anomaly. It is sure that both vehicle and the payload are destroyed and it was not unveiled when new Amos-6 will be delivered to orbit. In spite of strongback tower, assembly hangar, towers with installed light system and Niagara water curtains system appeared to be untouched with explosion so probably work to bring SLC-40 launch pad to fully operational status will not take long. SpaceX also have not given any details about future missions planned for rest of the 2016, but it should not be surprising if following missions will be moved in time.
On picture above: SLC-40 before explosion.