SpaceX Falcon 1 Launch Attempt #2

http://kwajrockets.blogspot.com/:
It looks like today's attempt will be pushed off. Pressure for the Main Chamber was 0.2% under the abort limit.

Missed by a hair...

The launch will go ahead VERY soon:
http://www.spacefellowship.com/News/?p=1929

in 10 minutes from now, we'll have a countdown again (if all is alright)

hmm webcast count down is still t-16

Restarts at 00:54 GMT (1:54 your time)

ahh cool!!!

i guess i'll have to hang on for a little while longer!!!

The webcast keeps cutting out on me. Sometimes I have to close the player and reconnect to get it going again. They don't seem to have enough bandwidth for the number of people watching.

Lucky you can always read
http://www.spacefellowship.com/News/?p=1929

hmm wonder what has going on... it looked like the upper stage started to shake more and more

My take on the situation (quote is by me on another forum):

Also I noticed the stiffener ring at the aft edge of the krestel bell tear free after a few seconds of operation. At the time nobody said anything so I assumed it was normal, however now I'm begining to think this is what happened.

- Stages seperate, lower stage fairing gives a significant 'wang' to the end of the second stage motor nozzle bell, this damages the aft stiffener ring.
- Second stage engine ignites and forces on the aft stiffener causes it to break away, nozzle is still structurally sound but more flexible than it should be.
- Slight damage to the nozzle or CG shift causes the rocket thrust vector to be slightly off, gimbal accounts for this and fixes trajectory.
- The action of the gimbal causes the now weak aft end of the engine bell to flex, momentarily causing a large force in the opposite direction of the correction.
- As gimbal moves to correct this new force, the correction flexes the nozzle again, creating an even larger counter-force.

The cycle grows as we saw until either the nozzle bell fails, a safety overide shuts down the gimbal or the rocket tumbles.

http://www.spacefellowship.com/News/?p=1929

A press briefing of Elon Musk is online!

I thought they might have reduced thrust more gradually before seperation to minimize sloshing. The seperation itself was very odd.

It looks like the 2 people who voted for Successful seperation, but early second stage failure were right. Unfortunately there is no real way to test stage separation except in flight.

Despite my disappointment that it wasn't a total success, I'm fairly happy with this launch. (though I'm unhappy that I couldn't watch it live...)

I think Elon's assessments were spot on. Yes, I'd expect nothing less than positive words from him, but I think he didn't overstate anything. It was a good day for SpaceX, maybe not a great day, but still a good one. Obviously they learned an awful lot from the first test flight.

I'm very impressed with the automatic sequencing and abort monitoring. It's not often that you see a rocket light up on the pad, abort and then fly successfully shortly thereafter.

I talked to my office mate who was part of the tech team for the flight 1 investigation. He was very happy with the performance, though obviously disappointed with the end results. SpaceX accomplished several difficult tasks flawlessly: stage 1 burn, max Q, payload fairing separation, stage separation, and stage 2 lit up nicely kept the rocket going until the flight termination.

It is unfortunate that telemetry was lost. I would think that the pre-loss telemetry is sufficient to determine what was going on prior to loss. I'm no comm expert, buy I'm curious if telemetry was lost due to sync problems during the oscillations.

It will be interesting to see if the control software couldn't compensate fast enough for the initial oscillation and thus induced further oscillations.

Again, I think this was a largely successful test launch. the first launch was quite a stumble. SpaceX pickup themselves up and made some great progress with this second flight. they've got some good talent.

I hope and expect they'll show improvement for Flight 3. I expect "third times a charm" (knock on wood) will work for SpaceX.

I wish them luck. I'm looking forward to the next launch and Falcon 9. It's time someone stuck it to BloMart (i.e. ULA)

- Alistair

Stiffener rings are typically used for stiffness during ground transportation and usually serve no function during flight. I've seen stiffener rings separate on other launches with no effect on second stage performance.

Still, your speculation is reasonable. It's possible that the oscillation was initially well within controllable parameters but continued to slowly grow until it got out of controllable limits.

Hopefully this is a relatively easy fix. I want to see two more flights this year.

- Alistair

I'm sorry to say that I was right. I was really hoping for a full success. But it was still a fantastic flight! Up until the control anomaly everything seemed flawless.