SpaceX Falcon I Launch

[Bob B.]

Have any of you been following SpaceX's launch of its new Falcon I rocket? They had a successful test launch on 20-March; below is a video:

Falcon 1 DemoFlight 2 Launch

I've posted this in the "hoax theory" forum because it demonstrates a pertinent argument. First, note how the first stage exhaust plume spreads out and becomes increasingly less visible as the air pressure drops (this becomes most noticeable after about T+2 minutes). Second, we get an excellent close up view of the second stage engine, which ignites at T+00:02:55. Note how the second stage exhaust gas is virtually invisible.

I think this may be the best video I've yet seen for demonstrating the fallacy of the "no exhaust flame" argument. Also the expansion of the first stage exhaust stream may help in debunking the "no blast crater" argument.

[Grand Lunar]

Oh, you know those HBers. They'll always find some way to support their arguement.

[gwiz]

bob said:

Have any of you been following SpaceX's launch of its new Falcon I rocket? They had a successful test launch on 20-March;

Partially successful, orbit not achieved due to loss of attitude control towards the end of the second stage burn. Agree with you about the flames, but also check out rocketcam videos of the Delta II, as the second stage engine on this is very similar to the Apollo spacecraft technology.

[sts60]

Partially successful, orbit not achieved due to loss of attitude control towards the end of the second stage burn.

Yeah, that coning motion was getting pretty bad towards the end.

[hplasm]

grandlunar1980 said:

Oh, you know those HBers. They'll always find some way to support their arguement.

Wires?

[JayUtah]

I'd like to see their data. At the top of my list of candidate causes is hysteresis in the guidance system.

[Count Zero]

On staging, it looked like the engine bell got nailed pretty hard by the first stage. Is this a common event?

[Edited to add:] I found an article about it here.

[JayUtah]

On staging, it looked like the engine bell got nailed pretty hard by the first stage. Is this a common event?

Recontact during staging is a common concern, but thanks to lots of good engineering and flight practice, it's a relatively uncommon event these days. SpaceX chose to build their second-stage nozzle out of a material designed to withstand strikes without critical damage. Lots of other nozzle materials that can withstand the tremendous heat and still maintain strength do so at the cost of brittleness. Nozzle strikes up to a certain degree are tolerated in SpaceX's reliability plan.

Guidance naysayers should note carefully that the vehicle was not under aerodynamic stabilization at staging. During chi-freeze the staging recontact knocked the vehicle several degrees off its heading. As chi-freeze is released, the engine immediately gimbals and returns the vehicle to controlled flight. The rocket did not "fall off" its thrust.

Everyone should spend a half hour at the SpaceX video archive. It shows many aspects of rocket booster development. I'm especially fond of the turbopump startup sequence video because I was on a pilot design project once for a gearbox in such an assembly. Ours kinda blew up though.

[Bob B.]

jayutah said:

Ours kinda blew up though.

Or as it is known in rocket business, you experienced a Rapid Unscheduled Disassembly.