Rocket 197

Ghouta Chemical Massacre:
Firing Directions 
Part 2: Rocket #197
August 13, 2017
(incomplete)

Part 2 in this series of six is for East Ghouta UMLACA/volcano impact #2, as I'm numbering it, though its makers stenciled the number 197 on it in red. This is the famous one that burrowed into a field, with its back end apparently bending forward. The location is easy to set and agreed by everyone, about 130 meters east of impact #1.

Coordinates: 38º31'14.7”N 36º21'26.6"E
It's probably the most widely seen rocket on video, being freely tampered with by activists, handling the bent tube and moving it around. (see photos at The Kurdish Cause, Brown Moses). This open tampering with the evidence is probably why the UN-OPCW investigators looked at a field impact nearby, but not at this one.

While this rocket is seen in different positions, the real bend and the surrounding damage clues suggest the bend seen at right is about how it impacted, and so can be read for direction clues; the view is roughly east, and the tube points roughly south. That's not hard to read as for general direction. Eliot Higgins decided at the time (Aug. 26):

The munition itself appears to have buckled over on impact, which seems reasonable as the center section of the remaining warhead is a hollow metal tube.  This would seem to strongly indicate the munition was fired from the north, where 6-8km away you'll find a number of military installations, connected by a 2km road to the 155th Brigade missile base.  In one version of events, the Syrian National Coalition has claimed the rockets were launched from bases housing the 155th Brigade.

Later, he came to agree these rockets had a maximum range of about 2 km, and started looking for regime-held areas that close (none identified for sure, but it remains possible)

"Sasa Wawa" at Who Attacked Ghouta also finds north. At impact site analysis, he notes how photos "clearly show the crater is oriented at a right angle to the plough lines," which run about east-west. So this "gives us another northern trajectory," in addition to impact #1.

Northwest readings agreed it appeared way more north. Our early assessment at ACLOS was a hair west of north. Resho Bistuyek at the Kurdish Cause blog agreed with my friend Petri Krohn that "the impact was slight off from a perfect northern origin, picture #2 "slightly favoring a NW origin."

FAE clues:

burn ring analysis - imprecise -  burn are extends further north into the field on the east side, as well as extending further along the facade to the east - damage uniform across the building, extending to the one east, suggesting a north-northwest trajectory similar to the rocket's apparent angle. However the building stops quickly to the right, so we can't see how far burns and damage there would go, and ground burning is harder to read, so the picture isn't complete. As noted below, a building 30 m to the west has high-level facade damage, sugg. the upper dome expanded quite a bit wider than the ground level burn marks (rising as it expands makes sense, and it would do both very quickly). In fact is seems to expand at least 40 meters in each direction.

The building facade damage is worth analyzing. Here's a start. The damage is worst low and in the center, with lighter damage extending clear across the neighboring building to the left/east, and middling damage to the central building's upper floors, and even to a building facade about 30 meters to the right/west. So far this isn't clear enough to add much; it seems like the worst damage is ahead, on a basic trajectory from the north.

North Consensus Challenged:
Sasa Wawa at Who Attacked Ghouta had seen two northern firing angles for impacts 1 and 2 but he seems to have misread #1 a bit, as it clearly came from further west. (see part 1).

Analysis by Michael Kobs in particular has established this. Seeking one firing location, which is the most logical, what everyone so far, including myself, has looked for - and finding angles to further  northwest (readings gathered here on Twitter). This considers 5 impacts, not so far including this #197, and some unclear spots pinned by others, with a black circle about 1.5 km away where all NW angles might converge. That's intriguing, and I largely agree; "embedded" (impact 1) seems to be on a line almost that exact, while I'm not sure sure about "garage door." (will be impact #4 here) and "sheeps" (will be #5). The others  (roof, wall) seem like decent ranges. Below is that Kobs map, to which I've added impact #2 and a direction range for how it seemed, and still visually seems to me.

So the Sasa Wawa conclusion - "The rockets were launched from a location north to Zamalka" - was premature, but also seems partially evident. This rocket 197 really does appear to point north, to the extent that the angle for impact 1 may not apply - they could be fired from two different spots, even though that's not the most likely scenario. At the moment, this north angle seems the odd one out, but so it is.

All the visuals aside, it's possible likely this too came from a bit more northwest than it seems, maybe even some 20-30 degrees. But otherwise, it's also possible, as it always was, that there were two or more firing directions involved, and maybe one is almost north, as it always seemed. If so, this rocket 197 would be fired from there, along with possibly those at the garage door and dead sheep sites (still reviewing, see parts 4 and 5) , besides possibly some of the unseen impact areas.

More Detailed Analysis

But all this is imprecise - the plow lines run a couple of degrees counter-clockwise from true east-west, so a line perpendicular to them would run a hair northwest. And then, is it exactly perpendicular? From a side view, it seems to angle a bit to the left,though it's hard to gauge, even with this sort of grid drawn on.

...from behind we see its back end angles a bit left from the middle part, which itself points a bit right, and angles however with the buried forward part. To me it looks like it flew in from behind and a bit from the right (in this view), but aiming about straight for the building, roughly in the middle of the span seen here. Then it snagged into the ground, and the engine's inertia bent the tube forward and a bit to the right - hence pointing a bit more south than its actual trajectory - a bit from the northwest. - straight-on appears almost due north. 

What might explain this triple bend is an unstable and spiraling rocket coming in on a yaw, as I try to show below. Yawing means flying on the gray line (not the actual angle, but confusingly similar - sorry - just for illustration), but bodily slanted a bit to the left on that line - that is, flying a little bit sideways. When the tank comes apart (releasing sarin or fuel droplets to ignite, depending) and the rocket impacts, it's tilted a bit right rather than exactly straight. So it would bent as the tail prtio tried to keep flying, before the forward bend. If it's anything like I sketch here, the tail end's orientation is more representative of the original trajectory than the middle bend or even the buried nose section. But at any rate, all angles are fairly close to each other , so these details only make a minor difference one way or the other.

This would take some more work, and maybe a better set-up than I can manage, to get a clear answer. For now, it may have been worth the rambling re-consideration, but it just looks about like it always did, even though that's now a bit of a problem.