SpaceX is due to report in early December the definitive cause of a huge launchpad explosion in September.

The fiery explosion destroyed a Falcon 9 rocket booster with a very expensive Facebook-backed commercial satellite. SpaceX spent the following months trying to determine the cause of the explosion and The Wall Street Journal reports that SpaceX CEO Elon Musk and his team will deliver a preliminary report to federal authorities in the coming weeks.

Thus far, it’s been thought that a fueling error was to blame during the launch pad test. SpaceX sources close to the investigation are now saying that a complex chemical interaction between supercooled fuel and carbon composite material attached to the outside of the booster’s helium containers created a breach that led to a volatile combustion. The investigation appears to have hinged on determining the exact combination of pressure, temperature, and fill rate.

If this turns out to be true, it will confirm suspicions that an operational error was at play. This would actually turn out to be good news for SpaceX, since it means the Falcon 9 hardware is still safe to use. An operational error simply requires changes in the fueling procedures that are used.

That means the company’s goal to return to flight before the end of the year might actually be achievable. Regardless, the company can’t really afford many more setbacks, and the delivery of the report as soon as possible would put Musk and his team in a better position to get back on track and prevent more delays in other missions.

Photos via SpaceX