The investigation by SpaceX into the September 1 explosion is ongoing, with the help of NASA, the Air Force, and the Federal Aviation Administration. The explosion happened during a routine filling operation when the engines weren’t on and there was no heat source available.
The Accident Investigation Team released a statement indicating that the preliminary investigation points towards a breach in the second stage cryogenic system, which keeps oxygen cool. How the breach formed remains unclear, though.
In a tweet, SpaceX CEO Elon Musk stated that the investigation is “turning out to be the most difficult and complex failure we have ever had in 14 years.” A few days after the tweet, he asked for people to send in videos and photos of the fireball, hoping to better understand what happened.
In footage captured of the event, there’s a quiet bang before the explosion, and an unidentified object (likely to just be a bird) is seen flying over the rocket as it explodes. Although no interactions are seen between the object and the rocket, some have suggested that the rocket was sabotaged from rival companies, the US government, or even aliens.
Although these hypotheses have a certain lure, rockets are literally explosive sticks. External agents, especially of extraterrestrial origin, don’t tend to cause as many rocket explosions as some might think.
Footage of the SpaceX explosion on September 1, with the mysterious object that's probably a bird flying over the rocket. USLaunchReport
[H/T: Washington Post]