After an exhaustive investigation, one which company founder Elon Musk said is “the toughest puzzle to solve that we’ve ever had to solve,” SpaceX has positively identified the cause of a September 1st pre-flight test that destroyed a Falcon 9 rocket and its Amos-6 payload. Confirmation came from Musk via a wide-ranging Friday interview on CNBC.
“I think we’ve gotten to the bottom of the problem.” “It was a really surprising problem. It’s never been encountered before in the history of rocketry.”
While few new details were forthcoming, Musk’s comments confirmed a company update one week ago that the investigation was closing in on what caused one of three helium tanks contained within the booster’s second stage liquid oxygen tank to rupture.
The failure took place during helium loading, where an as yet unspecified chain of events turned the liquid oxygen into a solid, which then reacted with the carbon composite material covering the tank. Given the constraints of ITAR regulations, it is possible that SpaceX may decline to provide the level of detail many watchers would like to see.
On October 13th, Elon Musk delivered a presentation to the U.S. National Reconnaissance Office (NRO) in which he was quoted by a leaked source in Space News as saying the “a leading theory” was the formation of solid oxygen on the carbon composite over-wrapped pressure vessel (COPV).
“It might have been formation of solid oxygen in the carbon over-wrap of one of the [helium] bottles in the upper stage tanks…If it was liquid, it would have been squeezed out. But under pressure it could have ignited with the carbon.”
With the cause of incident positively determined and apparently addressable through procedural rather than physical changes, SpaceX is now looking to resume Falcon 9 launches in mid-December, although neither the payload not launch site has been announced. Had the Amos-6 satellite launch taken place as planned, the next mission up for SpaceX would have been the launch of 10 Iridium Next satellites out of Vandenberg, Ca, which was scheduled for September 19th at the time of the ‘anomaly.’
Thus far, SpaceX has said very little about the extent of the damage incurred at Space Launch Complex 40 by the September 1st accident, but it appears to be fairly extensive, particularly to the transporter/erector which serves as the vehicle’s launch tower. Fortunately for the company and its customers, SpaceX had already been working towards a late 2016 activation of its Falcon Heavy and NASA mission pad at Launch Complex 39A at the Kennedy Space Center, a few miles north of SLC-40, which is located on Cape Canaveral Air Force Station. Whenever the next Falcon 9 lifts off from the the U.S. East Coast, it will almost certainly be from 39A, the historic pad which hosted most of the Apollo and Shuttle flights.