Musk Statement on SpaceX Accident, Launch Delay

A statement from Elon Musk posted on the SpaceX website yesterday sheds a little more light on Friday’s test accident in Texas, while suggesting that delay of the AsiaSat 6 launch was due to an abundance of caution:

SpaceX has decided to postpone tomorrow’s flight of AsiaSat 6. We are not aware of any issue with Falcon 9, nor the interfaces with the Spacecraft, but have decided to review all potential failure modes and contingencies again. We expect to complete this process in one to two weeks.

The natural question is whether this is related to the test vehicle malfunction at our development facility in Texas last week. After a thorough review, we are confident that there is no direct link. Had the same blocked sensor port problem occurred with an operational Falcon 9, it would have been outvoted by several other sensors. That voting system was not present on the test vehicle.

What we do want to triple-check is whether even highly improbable corner case scenarios have the optimal fault detection and recovery logic. This has already been reviewed by SpaceX and multiple outside agencies, so the most likely outcome is no change. If any changes are made, we will provide as much detail as is allowed under US law.

— Elon Musk

A “corner case” is a term used to describe a fault condition caused by multiple factors exceeding their limits at the same time, cumulatively resulting in a fault.  An “edge case” occurs when only a single element exceeds its normal operating parameters.  Musk’s statement seems to confirm that the vehicle malfunction in Texas was not a fault with the engines or propellant flow systems, which would have been much more troublesome, but instead the result of a blocked sensor and a more limited fault recovery system than is found on the operational Falcon 9.

While lurid headlines of an exploding rocket over Texas are not publicity anyone asks for, SpaceX is likely doing itself a favor in temporarily delaying the AsiaSat 6 launch.  Both NASA and the Air Force will be closely monitoring the data derived from extended testing, as Musk’s post allude. What matters most however, is not the specifics of what happened with the test vehicle, or what, if anything is uncovered in triple-checking the Falcon 9’s fault termination system. What matters most to the both NASA and the Air Force is that the flight culture of SpaceX launch operation remains one of safety and mission success. Both have paid dearly when their own culture was otherwise.

At the same time, what matters most to space enthusiasts, and the reason why SpaceX is followed so closely in the first place, is that the company is willing to take risks in constantly pressing to advance the state of the art. Here it faces a challenge, to not allow the necessary mission success culture in flight operations cause the company to become paralyzed in the very different arena of research and development. So far, it seems to be finding just the right balance.