1h1 hour agoJeff Foust @jeff_foustYou’ll see a lot of amateur speculation and analysis of today’s F9 explosion. Use with caution; almost all of it will turn out to be wrong.
Quote from: Dagger on 09/01/2016 08:06 pmMade a little gif. Don't know how accurate it is:It's hard to draw much from attempting to find the 2D mid-point of an over-exposure.
Made a little gif. Don't know how accurate it is:
Quote from: ellindsey on 09/01/2016 08:26 pmAccidentally (or deliberately) activated FTS would have activated the FTS for the entire vehicle, not just the second stage. This failure was too localized to be FTS.That exactly looks like what happened. The whole stack just exploded really fast.
Accidentally (or deliberately) activated FTS would have activated the FTS for the entire vehicle, not just the second stage. This failure was too localized to be FTS.
Quote from: dnavas on 09/01/2016 08:29 pmQuote from: Dagger on 09/01/2016 08:06 pmMade a little gif. Don't know how accurate it is:It's hard to draw much from attempting to find the 2D mid-point of an over-exposure. That's why most people that attempt to locate it use the diffraction spikes instead (hence the X shape above). They are much more localized as they trace out the highest intensity light source at that instant. It's reasonable to assume that's where the event originated.
Wise words from Jeff Foust.Quote1h1 hour agoJeff Foust @jeff_foustYou’ll see a lot of amateur speculation and analysis of today’s F9 explosion. Use with caution; almost all of it will turn out to be wrong.
FH is worst case equivalent to 196 tons of TNT. The HIF is 1900 feet from LC-39A, and at that range the only effect should be some broken windows, and possibly some falling flamey bits - but neither are likely to cause major damage to a steel building or anything reasonably sturdy inside it.
I'm going to speculate wildly here (Mod, please delete if inappropriate);Point 1; The CRX7 failure occurred in the second stage. Point 2; This explosion *appears* to have originated in the second stage. Speculation: to my eyes, this event appears to have been highly energetic from the first moment it appears. Further speculation; would a COPV failure (sudden release of He into the LOX) fit observations?
Some notes:1. There's no similarity to CRS-7 event. "Excessive venting" that some people claim here is probably mostly due to the fact that surrounding air was almost saturated with moisture. Pressure vessel overpressure rupture would have caused massive cloud initially, which then would have perhaps detonated. Not the other way around.
Watching this in slow motion, it appears that in the first frame with fire that there is a long downward finger of flame and smoke that dissipates as the fire ball erupts. Is there an umbilical that could have come off and sprayed something downward?
Quote from: Kabloona on 09/01/2016 08:32 pmWise words from Jeff Foust.Quote1h1 hour agoJeff Foust @jeff_foustYou’ll see a lot of amateur speculation and analysis of today’s F9 explosion. Use with caution; almost all of it will turn out to be wrong.Agreed, thus why I explicitly put a low emphasis in my post.
Quote from: ugordan on 09/01/2016 08:32 pmQuote from: dnavas on 09/01/2016 08:29 pmQuote from: Dagger on 09/01/2016 08:06 pmMade a little gif. Don't know how accurate it is:It's hard to draw much from attempting to find the 2D mid-point of an over-exposure. That's why most people that attempt to locate it use the diffraction spikes instead (hence the X shape above). They are much more localized as they trace out the highest intensity light source at that instant. It's reasonable to assume that's where the event originated.Sorry, but in this case, those spikes (actually in-lens reflections) show the average center of the oversaturated fireball. Nothing else.
The biggest thing I don't understand is what is the ignition source? Even if the O2 tank had an overpressure, underpressure, or any other failure mode, why would the first thing we see be blinding fire? Some static or something would probably catch it eventually, but without the engines running you could mix O2 and RP-1 and it would still not self detonate.Am I missing something? I realize my optimism toward SpaceX might make me favor the least damaging outcome, but I just don't see how anything other than an explosive charge could have detonated so quickly. TEA-TEB or hypergolics could easily cause a bad day, but they don't appear to have been involved unless they were being loaded into S2 by the umbilical at the time.
Sorry, but in this case, those spikes (actually in-lens reflections) show the average center of the oversaturated fireball. Nothing else.
Quote from: king1999 on 09/01/2016 08:31 pmQuote from: ellindsey on 09/01/2016 08:26 pmAccidentally (or deliberately) activated FTS would have activated the FTS for the entire vehicle, not just the second stage. This failure was too localized to be FTS.That exactly looks like what happened. The whole stack just exploded really fast.It really didn't. There was a localized explosion in the second stage with a relatively slow progressive failure down the stack. If it was FTS, the whole vehicle would have ceased to exist in the span of two or three frames.
Quote from: intrepidpursuit on 09/01/2016 08:37 pmThe biggest thing I don't understand is what is the ignition source? Even if the O2 tank had an overpressure, underpressure, or any other failure mode, why would the first thing we see be blinding fire? Some static or something would probably catch it eventually, but without the engines running you could mix O2 and RP-1 and it would still not self detonate.Am I missing something? I realize my optimism toward SpaceX might make me favor the least damaging outcome, but I just don't see how anything other than an explosive charge could have detonated so quickly. TEA-TEB or hypergolics could easily cause a bad day, but they don't appear to have been involved unless they were being loaded into S2 by the umbilical at the time.If the fuel-oxygen mix is right, it only takes a tiny spark. Electrostatic discharge, a momentary arc from a switch opening or closing, really anything...