Largest Hybrid

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JAL3

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I have a vague memory of somebody, I thought Hypertek, offering large, 152mm O Hybrid motors but I find nothing of the sort on their site.

Was I just imagining it?

Does somebody else make it?

What is the largest hybrid you know about?
 
One of the California guys, and his name is escaping me at the moment, has built an R hybrid.

-Kevin
 
Here is a video of a launch of the largest hybrid motor. You may recognize it.

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MK
 
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Title:performance Analyses of HPDP 250K Hybrids Author(s):park, O. Y.; Bryant, C. T.; Carpenter, R. L. Abstract:The Hybrid Propulsion Demonstration Program (HPDP) was formed to develop hybrid propulsion technology to a maturity level required to enable the propulsion industry to commercialize hybrid boosters for various space launch applications. The program culminated in a series of large-scale 250,000 lbf hybrid motor development tests. Three tests with two 250K Hybrid Motors have been recently conducted at NASA's Stennis Space Center utilizing two different Forward End configurations and a HTPB, LOx propellant system. Ballistic characterizations. motor performance analyses and stability are presented. The documented combustion instabilities in these hybrid combustion tests have been investigated based on the data obtained. Resonance between two different pressure fluctuations, one in the Forward End and the other in the After End, was analyzed and evaluated. NASA Center:Marshall Space Flight Center Publication Date:[2000]
 
Title:performance Analyses of HPDP 250K Hybrids Author(s):park, O. Y.; Bryant, C. T.; Carpenter, R. L. Abstract:The Hybrid Propulsion Demonstration Program (HPDP) was formed to develop hybrid propulsion technology to a maturity level required to enable the propulsion industry to commercialize hybrid boosters for various space launch applications. The program culminated in a series of large-scale 250,000 lbf hybrid motor development tests. Three tests with two 250K Hybrid Motors have been recently conducted at NASA's Stennis Space Center utilizing two different Forward End configurations and a HTPB, LOx propellant system. Ballistic characterizations. motor performance analyses and stability are presented. The documented combustion instabilities in these hybrid combustion tests have been investigated based on the data obtained. Resonance between two different pressure fluctuations, one in the Forward End and the other in the After End, was analyzed and evaluated. NASA Center:Marshall Space Flight Center Publication Date:[2000]

Thanks for the ref, Bob.
 
So much speculation and mis-information in this thread.

The rocket was Tom from Contrails L3 attempt. It did not go so well.

The grain was a regular production grain, it did NOT contain AP.

They took a long time filling the motor and dropped the pressure of the fill tanks. This let the chamber pressure creep up closer to the nitrous pressure. It resulted the the great big aluminum firecracker that you see in the photos.

I believe 3 of them were clustered in England.

Edward
 
Thank you for clearing that up. I had heard from a fellow rocketeer that it contained AP, I guess he had beed misinformed.

Nope. HTPB, and some other stuff, but no AP.

The nitrous is the oxidizer in their motors.

-Kevin
 
So much speculation and mis-information in this thread.

The rocket was Tom from Contrails L3 attempt. It did not go so well.

The grain was a regular production grain, it did NOT contain AP.

They took a long time filling the motor and dropped the pressure of the fill tanks. This let the chamber pressure creep up closer to the nitrous pressure. It resulted the the great big aluminum firecracker that you see in the photos.

I believe 3 of them were clustered in England.

Edward
It think what you mean is that because it took a long time to fill, the nitrous pressure in the motor was lower than usual because of the extra evaporative cooling that reduced the nitrous feed pressure into the thrust chamber.

Once you ignite the motor and burn out the nitrous supply line, the pressure drops even more, and if there is any combustion instability, and in any high thrust hybrid there is likely to be some, pressure oscillations will occur and if the chamber pressure exceeds the nitrous pressure, a flame front will propagate back throught the injectors and detonate the nitrous in the flight tank, and that is exactly what happened.

Bob
 
The Contrail O is the largest production HPR hybrid AFAIK.... the Reliant Robin Space Shuttle in the UK was powered by six of them clustered IIRC, along with about another 20KNS of solids.

From what I've seen and heard they aren't a very easy motor to work with, and the mass fraction is pretty dire.

Personally I've been significantly unimpressed by all the Contrail stuff, but that's just my opinion.

The 8" hybrid you were refering to was Jeff Jakobs' BALLS project which he's flown (and tried to fly) a few times... it's a pretty serious project.

Quite a few amateur groups have flown big hybrids, we built a 4" 'P' hybrid which flew at BALLS back in 2002. Hypertek (well, EAC anyway) have fired up to 16" motors as I recall, the bigest being for the Tier 1 programme before they were deselected from the SS1 project.



Ben
 
How long was the P motor? Back of the envelop calculations I'm getting over 10'?!?

Edward
 
How long was the P motor? Back of the envelop calculations I'm getting over 10'?!?

Edward

Horribly long :)

The chamber was just over 3ft long, then that was coupled to a 3m tank (about 10ft). So the motor alone was about 13ft+, then we had recovery and avionics on top of that. IIRC the finished rocket was well over 21ft... which is long for a 4" rocket :)

Worked well though... flew damn straight :) Got to about 26,000ft despite much of the divergent section of the nozzle cracking off on ignition due to it having been temperature cycled earlier when we dumped a Nox load through it.

It was about a P2600 or so, only very low 'P', about 43,000Ns I think in the end.

Must fly it again some time :)


Ben
 
Awesome! My M900 rocket was a touch over 10' long, and flew rope straight. I guess next time you'll have to go to 200mm to keep the length down :)

Edward
 
That's what I was thinking of. THanks!

Does anyone have any experience with Contrail?

I have a 75mm contrail motor and I like it. It is well designed and I am able to cast my own grains for it. One of the things that I like about it is that the vent comes out the nozzle.
 
I have a vague memory of somebody, I thought Hypertek, offering large, 152mm O Hybrid motors but I find nothing of the sort on their site.

Was I just imagining it?

Does somebody else make it?

What is the largest hybrid you know about?

Just to let the Forum know Contrail Rockets made and still makes the O-6300

The Top Gear Space Shuttle used 6 O-6300 you can still find it on YouTube or if you want to see a single one
The Rocket Men: Blue Peter Rocket

https://youtu.be/3kntaSdgfAw


The Rocket Men: Blue Peter Rocket
The Blue Peter rocket was launched from an MoD weapons range near Kingussie in the Scottish Highlands.

This is a single O -6300 with a full load of 15500cc of NOS.

Tom Sanders
Contrail Rockets

View attachment O6300.pdf

shuttle.jpg
 
That's what I was thinking of. THanks!

Does anyone have any experience with Contrail?

I've fired a few. They are the simplest Hybrids I know to fill and fly.

The O6300 152mm was tested at a launch.
Unfortunately, they tried to force the tight-fit motor into the rocket by pulling it down over it and pinched one of the lines.
they decided to fill and it sprung a leak so they had to dump the tank.
That goes down through the grain and it is suspected later that the grain was rendered useless by the freezing process.
They suspect after liftoff large chunks blew away and when it over pressurized it blew the whole bottom of the rocket.
Was not pretty.

Had it not been frozen like that they claim it would work fine.
They did certify it.
 
That's what I was thinking of. THanks!

Does anyone have any experience with Contrail?

I flew my Level 3 cert flight in Canada using a Contrail M. It was very straightforward and easy to prep and great to see. Members of the club I'm in have flown many of various sizes. They're always neat.

Sorry for the necro thread. I'm not sure why it showed up in my viewer.

Steve Shannon
 
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One of the California guys, and his name is escaping me at the moment, has built an R hybrid.

Jeff Jacobs.
Flew more like an anemic O.....
 
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