Last month, one of SpaceX’s rockets blew up while awaiting an engine test, the cause of which remains mysterious. Predictably, conspiracies and speculation about what happened have since, of course, appeared everywhere on the Internet, with the company yet to find the cause.

And a new piece of information has just come out will definitely fan the flames. The Washington Post reports that after viewing footage of the explosion, SpaceX asked for access to the roof of long-time rival company United Launch Alliance (ULA), as part of the rocket fireball investigation.

An anonymous SpaceX source reports that they met with representatives of the ULA and, in a "cordial, not accusatory manner", asked for access to the roof of SMARF, the facility used by ULA for the refurbishment of rocket motors. SMARF is located just under 2 kilometers (just over a mile) away from the SpaceX launch pad.

ULA, which is jointly owned by Lockheed-Martin and Boeing, refused access to the SpaceX employees but allowed Air Force investigators to inspect the roof. They found nothing connecting SMARF to the rocket explosion.

As for why the check was necessary, in an emailed statement SpaceX said:

"The Accident Investigation Team has an obligation to consider all possible causes of the anomaly, and we aren’t commenting on any specific potential cause until the investigation is complete. A preliminary review of the data and debris suggests a breach in the second stage’s helium system, but the cause of the breach is still unknown. We have sought all available data to support the investigation in a timely manner following the anomaly, as expected for any responsible investigation.”

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]