I'd be interested in seeing the video if you figure out a way to pass it around. I had to leave for a business meeting 15 minutes before launch. I hope Doug got his mocha. I had a nice Cabernet.

How large is "fairly large?"

http://spacex.com/video_gallery.php

Seems pretty clear to me that the Stage 2 engine got smacked by Stage 1 and 12 seconds later part of it ripped away.

3:28/3:29 - Stage 2 bngine bell getting soundly rung as stage 1 separates
3:41 - Edge of the Stage 2 engine bell starting to look noticably ragged
3:49 - "Ring" detaches in 2 pieces

I'm having problems cutting stills from the video but the timings should make it simple to find for those curious.

The SpaceX site has an interesting comment on the Kestrel's Nozzle construction:

That was definitely a lot more than a dent. hmmh

Launch video on YouTube.

What would be the functional impact of losing this "ring" at the engine nozzle? It seems to me the big problem arose due to buildup of an oscillation around the spacecraft roll axis. A case of positive feedback perhaps where the engine gimbal control actually winds up feeding the oscillation further, or maybe the effect just grew stronger due to rapidly diminishing mass of the vehicle.
I don't believe this is a pogo oscillation because IIRC pogo is a longitudinal oscillation. Of course, it's difficult to judge from the video whether any pogo effect was present because the camera probably wouldn't pick it up.

That ring is supposed to detach remember - so I wouldn't factor that into it at all.

I hate to admit Jeff Bell called it right, but he was right
Falcon failed and the majority of the private sector is going no where fast. They can try and spin this whatever way they wish but if it was NASA, the word 'failure' or 'multi-million dollar disaster' would be all over the medias news headlines and rightly so
SpaceX lost their payload yet again

Falcon 1, The World's Lowest Cost Rocket to Orbit.......maybe the subject title needs amending.......

That vehicle didn't tick all the boxes, but I wouldn't call it a total failure. Bell's take on SpaceX is no more right today than it was yesterday. Yeah - Elon's putting a positive spin on things - but when you look at the price of that LV, a new start up with 1.5 launches to their name - I think that was a very good mission. Hell - if it takes another 2 launches to get it spot on - they will then be offering a cheap, rapid LV. No one said it would be easy. No one said it would work first time. Calling the entire program a failure is, at this stage, hideously premature.

Doug

Doug do you have a reference that shows that the ring detach is by design?

http://www.spaceflightnow.com/falcon/f2/07...fingquotes.html

Odd to rely upon a temperature sensitive bonding agent to control the release of a stiffening ring.

That sounds more like the description of a failure mode than a flight asset.

I wonder if they charge extra for bugs in the soup in the local canteen:)

What we saw in the video could be caused by a number of things, but nozzle erosion and burn-through is definitely one of them.

We could only see about 30% or so of the entire engine bell. A really small burn-through could have occurred on a part of the nozzle that wasn't immediately visible. And that could have imparted a rolling moment to the stage.

Of course, there are a lot of other things that could have happened. I suppose we'll have to wait and see what SpaceX says about their telemetry and the tale it tells.

-the other Doug

I've seen things like wiring break loose off Delta second stages as well and wouldn't really attribute that as an abnormal scenarios.

Word on the NSF forums is the first stage recontact might have kicked off the propellant sloshing and it started an oscillation that fed off the attitude control countermeasures (positive feedback, an ugly beast) and it just lost battle with it after a while. They are saying the 2nd stage nozzle most likely didn't receive any damage (it's apparently pretty rubber-like), but the nudge started an oscillation chain reaction. Or maybe it was simply a case of a closed-loop where guidance didn't account for positive feedback effects like this when small attitude changes are allowed to grow rapidly.

Dvandorn, the nozzle heating up is perfectly normal as it's a radiation cooled design, it's not ablative nor regenerative cooled. I suspect it ought to have become much brighter glowing if a burn-through was to happen. In any case, a burn through would probably manifest itself as a sudden kick of the engine bell in one direction and I don't see that from the video. All there is is a gradual increase in oscillations, nudging both the engine and the rest of the vehicle.

"The second test launch of Falcon 1 took place today at 6:10 pm California time. The launch was not perfect, but certainly pretty good. Given that the primary objectives were demonstrating responsive launch and gathering test data in advance of our first operational satellite launch later this year, the outcome was great. Operationally responsive (ie fast) launch has become an increasingly important national security objective, so demonstrating rapid loading of propellents and launch in less than an hour, as well as a rapid recycle following the first engine ignition are major accomplishments."

they're sort of right aren't they?