Sunday, February 12, 2012

The 5th Annual International Rocket Weekend, 1996

The 5th Annual International Rocket Weekend

August, 1996

Kelburn Country Centre, Ayrshire, Scotland.

I came to this page searching for an image of this rocket:

The Comanche 5, that supposedly flew on a D12 - D12 - C6 - C5 - C6 to 4,000 feet! This image shows Marcus Lauder, the builder.


Dick said...

I wonder how the altitude was verified. I had to do a back of the envelope check and I guess a D12 could in theory boost such a model. However, I have seen several stock Comanche's go pretty much cruise missile by 3rd stage ignition due to weather cocking. It still seems more likely that 4k was the distance from the pad v. altitude. The drag of all those stacked fins must be pretty bad.

Dick said...

Here is a video of a D-D-D-E rack rocket build by Rocketjunkie. A rack rocket has much better theoretical performance than standard stack.

Dick said...

BTW, I think you have one too many 'C's above.

High Power Rocketry said...

I did not do any fact checking, got this info from here:

I had one too many D12s!

I think 5 stage comanche is possible, but risky. Ultra-low wind would be needed. Considering the number of stages, 4000 feet does not strike me as so great actually, since a good C motor can do 1500 feet alone.

High Power Rocketry said...

With this kind of staged rocket, rack rockets may indeed be the better choice. But with staging in general, rack rockets are not the best option because they only discard the minimum amount of mass at each stage. A full length single motor (such as a 24mm G long burn motor) would beat four D12 motors any day. Such a D motor could break about 10,000 feet in an optimal rocket. Part of the problem is these rockets do not stage from significantly (ie 4x) larger lower stages.

Anonymous said...

It was partially an exercise in optimism but the boost was remarkably straight. As for the altitude, all I'll say is consider it under-reported, and measured in ways not to be encouraged. The stages didn't fall too far from the launch site.

The 4 booster stage motors were all *-0s rather than what's reported on the records page, as you'd expect.