Jeez - just read that Saturn V paper - thanks for posting Wiggy.
Now that would have been one helluva bang!
Did I read right - 33 secs duration, 1400ft diameter, 1 atmosphere of over pressure at 2500 dg F!
Mental image of beehive hair-do-ed gal typing out report, authored by white short sleeved shirt, skinny black tied, horn-rimmed glasses rocket scientist.
With short back & sides, and pen protector of course.
Have seen that quote before but still love it... cheapest govt contractor.:)

When reporters asked astronaut Alan Shepard what he thought about as he sat atop the Redstone rocket, waiting for liftoff, he replied: "The fact that every part of this ship was built by the low bidder"

Blimey, that dirtrag of a so called newspaper can't even get basic facts right. Facebook did not own that satellite, hence Facebook did not loose any money. The satellite was owned by an Israeli company called Spacecom. Facebook was merely leasing bandwidth. :ugh:

Subscribing to FB o oning a profile isn't some kind of a bad-tasting medicine that you GP asks you to take inorder to save your life, you know? Chillax man, wiping off the servers might also have some consequences on people employed to look after them...

Keeping in mind too ...

- Where does our SLF post those holiday snaps that inspire their friends and associates to travel with us? Facebook (and instagram -- same company)

- Where do the travel bloggers post links to their videos, photos, and blogs that promote travel? Facebook.

- Where do the travel agents post advertising promoting their services? Facebook

- Where do our airlines post advertising to promote their services on their websites? Facebook.

- Where do businesses start their advertising? Facebook.

Facebook offers incredibly targeted advertising - without it I suspect that more than a few of us would be out of a job due to decreased demand for bums on seats.

Should be some good overtime prospects for the engineers at the satellite building plant. :)

USA aviation sources are indicating it was being fueled and LOX was involved

How do crooks know when and where you will be when travelling, on which flight and to which destination for one of those wonderful holidays all found on F@(Eb00K ??

Well, in my case, they know where I've been but never where I am or will be ;)

In the USLaunchReport video (see link below), there is about a 5.5 second delay between what is seen and what is heard - the camera is about 1.5 miles away. About 5 seconds before the report of the initial explosion, there is a very large bang sound, like someone striking a garbage pail with a hammer. The sound clearly originates in the distance, something that is made more likely by the fact that the launch site and surround would have been basically abandoned for a live fire test.

Now, visually, there is no event at the launch site that corresponds to this loud sound. It would have come at about 1:06, 5 seconds before the explosion. What could make such a large noise yet leave no visual record?

Some time ago, the SpaceX Falcon 9 CRS-7 mission failed when, just as in this case, the 2nd stage LOX tank failed during flight. The helium pressurization for these 2nd stage LOX tanks is derived from a smaller vessel that is actually housed within the tank and secured to it with steel struts. When the LOX tank is full, there is a large buoyant force on this vessel, like a football held under water, and this puts great stress on the support infrastructure. The in-flight failure was caused by failure of the securing struts, at which point the now-free helium vessel rocketed (ha) to the surface of the liquid oxygen pool and slammed into the LOX tank wall, fatally weakening it.

It seems possible that the loud noise heard on the video is the audible report of the same event. 5 seconds later, the tank fails.

https://www.youtube.com/watch?v=_BgJEXQkjNQ

The oxygen storage tanks at the Cape seen in old films have giant black LOX letters painted on them. LOX has been used in space flight to mean liquefied oxygen for many decade

DeSitter - Agreed.

LOX has been widely used as convenient short hand for straightforward unadulterated liquid oxygen in the spaceflight industry for decades so I don't think this is a case of the journalists getting it wrong.

If you have a look towards the back of the NASA technical paper on fireballs I linked to a few posts back you'll see "LOX" used both in one of the references and also in the graphs....

That's some mighty fast moving sound if it went 2.5 miles in 5.5 seconds. ;)

Be fair it also saves Advanced Persistent Threats huge amounts of money and time.

However, as I understand it, the in-flight failure was due to acceleration forces, which would be going in the opposite direction to bouyancy. They've put extra effort into checking every single strut since then. and I presume the second stage has been test-fired (and, hence, previously fuelled), like the first.

It's possible it's a related problem, but, from what I've read, the failure seemed to start around the umbilical attachments, which would make them a prime candidate. If it disconnected and started spraying liquid oxygen around, that would have been bad news.

1.5 not 2.5 :) typo oops

the big explosion was the satellite hitting the ground and it's ~2 tonnes of hypergolic fuel exploding.

the initial flash-fire looks like it's from outside the second stage where the LOX umbilical is connected.

one can only speculate that either there was a failure in the umbilical/coupling or some contaminate came into contact with the O2 venting, a lot of things get very incendiary in a pure O2 environment.

There are three main explosive reports in the initial event 1) the initial tank rupture 2) a much larger report 3 seconds later, possibly from the RSO operating the self-destruct mechanism and 3) the report from the satellite stage toppling to the ground about 11 seconds after the first report.

Nicely spotted AirBubba! I counted 12 seconds from flash to bang on the video myself though. So at 340.3 m/s at sea level (I assumed sea level as I have no idea of the elevation there) it makes 2.2 NM (2.5 statute). Looks like that cheeky speed of sound was sticking to the rules after all ;-)

Pad was within say 50 feet above sea level. But speed of sound is a function of temperature- not pressure/altitude