FTS charges on solids tend to be linear shaped charges designed to split
the case and terminate thrust. As Henry said, on liquids a relatively small
charge to burst the tank should be sufficient. Especially since the tanks
are structural so failure of one tank should be enough to take out the
whole vehicle in powered flight (what the FTS is designed for). The initial
explosion to me looks concentrated and could be a smallish detonation of an
FTS "point" charge. Then the fuel and oxygen tanks rupturing would produce
the big fireball.
I would expect anything to do with leaking liquid oxygen or liquid air
would be more of a smoky conflagration (possibly followed by a big
explosion if LOX and kerosene tanks are compromised). This happened too
fast, IMHO.
A tank rupture like on CRS-7 would send out a big plume of LOX before any
ignition. There's GOX venting, but that looks like normal venting from the
two stages.
On Fri, Sep 2, 2016 at 10:38 AM, David Spain <david.l.spain@xxxxxxxxx>
wrote:
I want to also rescind also that the activity might be on the other side.
I don't know how much manipulation has been made here. There's at least the
possibility that this is a composite image of an older image with the
explosion edited out in a way that makes it appear to be on the backside.
The author's main objective was a ray-trace.
Dave
Sent from my iPhone
On Sep 2, 2016, at 12:05 PM, Henry Spencer <hspencer@xxxxxxxxxxxxx>wrote:
Sackett in the Facebook SpaceX group. Looks like either an external source
On Fri, 2 Sep 2016, David Spain wrote:
A photo published this AM on NSF appears to back you up. From Ross
or if from the rocket from the backside of that photo...
isn't buried deep inside to blow the whole thing apart, it's out on the
Well, careful here -- a destruct charge (aka FTS) for a liquid rocket
outer skin to rip the tank open. (The purpose is to reliably terminate
thrust, not to blow the whole rocket into itty-bitty harmless pieces, which
is basically impossible.) And preferably on the tower side of the rocket,
so it's reachable for maintenance and checkout. So the location shown in
that image isn't incompatible with that explanation.
Henry
