Launch Pad Explosion during Static Test Fire - Sept 1 2016

[Brovane]

A .50 BMG rifle firing a MK211 Raufoss round (AP, HE, Incendiary) could set off the explosion. The F9 is a large target, it could have been hit from 2-miles away. Not saying that this is what occurred but is a possibility. A suppressor could have been used to muffle the rifle noise and the resulting explosion would have covered up the supersonic crack of the bullet.

 

[favo]

Wouldn't a bullet hole be found during inspection of the wreckage? Or was the fire hot enough to melt the metal skin of the rocket?

 

[anticitizen13.7]

Wouldn't a bullet hole be found during inspection of the wreckage? Or was the fire hot enough to melt the metal skin of the rocket?

I don't know, but the collapse of the rocket and subsequent detonation of the fuel could wipe away any evidence of physical sabotage.

 

[Dangerous Fish]

What a load of nonsense is being spouted about this.

If we're going to speculate, for goodness sake let's make it believable speculation.

 

[bro1999]

What a load of nonsense is being spouted about this.

If we're going to speculate, for goodness sake let's make it believable speculation.

Exactly. Which is why we should focus the discussion back to the most likely cause:

 

[anticitizen13.7]

What a load of nonsense is being spouted about this.

If we're going to speculate, for goodness sake let's make it believable speculation.

If that's directed at me, then I will only point out that sniper attacks occur with some regularity in the United States.

In 2013, a PG&E transmission station in San Jose, California was disabled by a team of snipers, who left over $15M in damage. The perpetrators were never caught: Sniper Attack On Calif. Power Station Raises Terrorism Fears PG&E's damage assessment was that the incident was not random vandalism, and that the shots fired were deliberately targeted to damage the transformers in a specific manner.

Just over 2 months ago, a U.S. Army reservist killed 5 police officers in Dallas, Texas in a sniper attack: 2016 shooting of Dallas police officers - Wikipedia, the free encyclopedia

There are many other examples of this in recent history. The reality is that firearms are easily obtained in the United States, through either legal or illegal means, and there are many many people with the training and experience to use long rifles effectively against large stationary targets.

I'm not saying that a sniper definitely caused the rocket explosion incident, but it is clearly within the realm of the possible.

At any rate, a sniper is a lot more believable than the various UFO and alien theories sprouting up on YouTube and Twitter.

 

[ecarfan]

The reality is that firearms are easily obtained in the United States, through either legal or illegal means, and there are many many people with the training and experience to use long rifles effectively against large stationary targets. I'm not saying that a sniper definitely caused the rocket explosion incident, but it is clearly within the realm of the possible.

I agree. It is a plausible explanation for the rocket explosion. SpaceX may not consider it a highly likely explanation, but I am sure they are not ruling it out, as one of Elon's recent tweets indicated (he said something like SpaceX has not ruled out an event external to the rocket as the precipitating case for the explosion).

It's now been over 10 days since the incident and still no indication from SpaceX that they have identified the problem.

 

[SteveG3]

The "objects" being discussed are certainly birds. If an external object struck the second stage and caused the explosion, it would be a very high speed and relatively small projectile moving incredibly fast. You would not see it in a video taken by an observer miles away, and you likely wouldn't even see it in one of the many high quality videos SpaceX was running at the time.

I am not ruling out the possibility of an external cause for the event, only saying it is a low probability and that obsessing over tiny dots in the videos available to the public is not a useful exercise. But feel free to carry on...

at this point, our views largely overlap, and where they differ I don't think is worth going over, I'll simply say, to me, probably all birds, but not certainly.

 

[dpeilow]

 

[Doug_G]

I agree. It is a plausible explanation for the rocket explosion. SpaceX may not consider it a highly likely explanation, but I am sure they are not ruling it out, as one of Elon's recent tweets indicated (he said something like SpaceX has not ruled out an event external to the rocket as the precipitating case for the explosion).

It's now been over 10 days since the incident and still no indication from SpaceX that they have identified the problem.

By "external" he almost certainly meant "something to do with the strong back or fueling systems".

I'm sure sabotage is worth considering as a scenario, but this is a rocket... there's lots of stuff there that can go boom.

 

[palmer_md]

Somebody took the time to re-sync the audio and video to get the sounds to match. Interesting that you can hear a sound at around 1:05 or :06 that is pretty loud given the distance to the microphone. I'm guessing that this is the sound that SpaceX is trying to locate with multiple audio and video sources. The sounds are 5-6 seconds before the big bang.

 

[DJ Frustration]

SpaceX has released the initial results of its investigation, which reveal that it believes a breach in the helium system in the Falcon 9's liquid oxygen system caused the sudden flare up.

Anomaly Updates

http://gizmodo.com/spacex-figured-out-why-its-expensive-rocket-exploded-1787007827

 

[jkn]

They do not tell what caused 'a large breach in the cryogenic helium system'. They do not say anything about bang heard 5 seconds before flames are visible in resynced video. Resyncing appears to be correct. Looking original video frame by frame: A frame shows no flames or fuel jet, next frame, 1/30 s later, has fireball at least 1/4 of rocket high. It does not get higher in next frame. So fireball expanded vertically 600 m/s and then stopped expanding in 1/30 s! I can understand this only if there was fuel premixed with air (or LOX). 5 s would have been enough for this mixing. Perhaps pressure wave from this first explosion damaged helium system.

I looked frames of original video from 1:06 and I cannot anything strange before explosion.

This reminds me of Apollo 1 fire. Unfueled, so no danger <-> engines not started, so no danger.

 

[JRP3]

So fireball expanded vertically 600 m/s and then stopped expanding in 1/30 s!

I'm not sure I understand what you mean, the fireball keeps expanding for a number of seconds after the initial explosion.

 

[jkn]

Yes it does, but I'm not interested in result. I want cause. In first frame fireball is higher than wide. In next few frames it will expand sideways, not up or down. Look only first 0.2 s.

There seems to be 2 explosions first very fast mainly vertical (outside of the rocket) then 1/30 s later slower mainly horizontal (from inside).

 

[Mike1080i]

This reminds me of Apollo 1 fire. Unfueled, so no danger <-> engines not started, so no danger.

Sadly as the Apollo 1 fire showed, things that are not normally considered highly flammable become so in a near 100% O2 environment.

Even cheese puffs are highly flammable.

 

[mediocreguy]

I can understand this only if there was fuel premixed with air (or LOX). 5 s would have been enough for this mixing.

It is my understanding that both stages of the rocket were fully fueled for the static test fire. I believe the bang or "rattling" that was heard a second or so before the main explosion was the breached helium tank banging around inside the LOX tank. This then caused an over-pressurization of the LOX tank causing a catastrophic failure of the LOX tank which also breached the fuel tank (the LOX tank sits on top of the fuel tank). Once the LOX and fuel mixed under high pressure, the main explosion occurred. Just my theory. SpaceX needs to get this upper-stage helium thing nailed down before their customers - especially NASA - lose confidence in their ability to launch successfully. All of the successful landings in the world won't make up for these vehicle and payload losses.

 

[GoTslaGo]

Sadly as the Apollo 1 fire showed, things that are not normally considered highly flammable become so in a near 100% O2 environment.

Even cheese puffs are highly flammable.

Cool link! Nice demonstration of LOX's potential!

 

[jkn]

It is my understanding that both stages of the rocket were fully fueled for the static test fire. I believe the bang or "rattling" that was heard a second or so before the main explosion was the breached helium tank banging around inside the LOX tank.

Video was taken about 4 km away (calculating from speed of sound). Could that make so loud sound? No, walls of the rocket are not very strong.

Post 97 from Pando, Sep 2, 2016 shows point of initial explosion.

 

[jkn]

After seeing picture in a post: HVM, Friday at 10:19 PM a theory come to my mind:

Struts holding He tank, marked by arrows in picture, look straight. Cooling those with super cold LOX increases tension. So one broke and caused first bang heard on video. Since strut was connected to outer wall of rocket, sound was loud.

This caused leaks in connector for fuel, LOX and He hoses (hydrazine?).

5 s later leaked fuel and LOX ignited in small space holding those connectors. This caused first fireball and released He to LOX tank. This broke wall between LOX and fuel tanks.

Long struts should be connected by flexible connector to allow changes in length. Did they forget this?