Mach Speed Club

Discussions on high/extreme altitude and mach busting rockets.

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Scoop1261
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Mach Speed Club

Postby Scoop1261 » Tue Sep 30, 2008 9:53 pm

A topic on one of the US forums sparked my interest, and prompted me to start this thread.

Perhaps all the flier's who have actual evidence of their Mach breaking flights can list their data showing evidence of exceeding Mach and some information about the airframe configuration for the interest of others.

I will happily post the opening evidence.

Image

The airframe is a dual deployment version of the Giant Leap Rocketry Firestorm 54 in filament wound fibre glass, it uses an Acme fin can and weighs in at 4lbs dry and is around 71" long. It is a 54mm minimum diameter.

Image

The engine used on this flight was a CTI K570 Classic with a total impulse of around 2062.9Ns and a burn time of 3.6s
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Postby Avachovy » Tue Sep 30, 2008 10:34 pm

this is going to be interesting!

i dont have actual evidence, but an estes yankee on a D21. It held together, never found it again!

Im wanting to get me a Raptor, then ill join the club :wink:
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Postby Kryten » Wed Oct 01, 2008 8:52 am

I thought you were doing an Apogee Aspire, launched on a "G"?
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Postby Avachovy » Wed Oct 01, 2008 10:18 am

yeah, we have that too. Started building it in time for the next launch!
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Postby october sky » Wed Oct 01, 2008 5:29 pm

I must say that all the people at the LDRS admired Scoops beautiful Firestorm ! Stunning looking rocket. 8)

Only problem, after 11500 feet flight, looking for it in the brown fields at 30+ heat ( lost the antenna from the transmitter) not so fun !! :lol:
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hotspot
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Postby hotspot » Wed Oct 01, 2008 7:33 pm

Got another firestorm on its way an all glass version this time for a K550 electronics will be the rrc2 and im using my csi tracking transmitter and reciever.

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Postby bpratt » Sun Oct 05, 2008 9:18 pm

Kryten wrote:I thought you were doing an Apogee Aspire, launched on a "G"?


I'm planning on sending my Aspire up at the November launch on a G80.

Hopefully I'll be able to find where it ends up landing. :)

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Postby hotspot » Sun Oct 05, 2008 10:13 pm

Flew my aspire 5 times the 10 sec delay is a little short you need atleast 13 seconds.

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Postby bpratt » Mon Oct 06, 2008 7:21 am

hotspot wrote:Flew my aspire 5 times the 10 sec delay is a little short you need atleast 13 seconds.


Oh okay, that's good to know. :)

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Postby Scoop1261 » Mon Oct 06, 2008 10:32 am

Avachovy wrote:this is going to be interesting!

Im wanting to get me a Raptor, then ill join the club :wink:


You may not exceed Mach as easily as you think using the Raptor.
It is just short of optimum mass to break Mach, unless conditions are very favorable.

The only available commercial motors that would potentially achieve your goal are the H268R & I200W, and even they will only just achieve Mach 1.02 & 1.07.

C'mon folks, there must be more of you out there with real evidence of surpassing Mach 1.0..........????
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Postby hotspot » Mon Oct 06, 2008 1:02 pm

Smoothing off the lip on the fincan would have got a few more feet per second well worth doing.

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Postby Scoop1261 » Mon Oct 06, 2008 1:30 pm

hotspot wrote:Smoothing off the lip on the fincan would have got a few more feet per second well worth doing.


Already done that
Why Limit Yourself?

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Impulse: A Whole Lot ..So much I've lost count!

hotspot
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Postby hotspot » Mon Oct 06, 2008 8:50 pm

Its yours I was talking about,,

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Postby blackbird » Wed Oct 08, 2008 7:41 am

I'm working on a rocket with the specific purpose of going greater than Mach 1. After working on the design for many months now, I am very sceptical about anyone that says they have gone mach. As far as I’m concerned if you can’t prove it then you haven’t.

Firstly, why bother going mach if you don't intend to obtain evidence. Going mach is wasteful as it consumes a lot of power. Also, if you intend to go mach you would want to fly a reasonable sized rocket so that you can see it at that speed and hopefully find it when it returns to the ground. You also have to remember that there is variability in the rocket motors and I'm guessing there could be up to 10% difference from one motor to another.

So really if you intend to go mach you would want to aim a little higher so as to compensate for any differences in motors and any inaccuracies in your simulations. Based on a reasonable sized rocket, a payload for obtaining evidence, and design variability, I believe the smallest motor that can do the job is a J motor (and only certain high thrust units).

It may be possible to achieve the above on a H ot I motor but this will be a small rocket and with the altitude it is likely to achieve it is likely you will not get it back.

My attempt is likely to happen some time next year so hopefully I can brag about it then.

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Postby The Wombat » Wed Oct 08, 2008 9:35 am

Try the H999 reload. You'd be doing mach by the time you got 200' AGL.

You will hear Mach.
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