NewEntity1
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I've only recently returned to model rocketry, and I don't even anticipate trying for Level 1 HPR certification until this summer. I doubt I would ever reach the point where I was doing actual experimental rocketry...I'll leave that to the experts.
However, my dream rocket (which I'll never build...but maybe somebody will
) would go something like this:
CATS went unclaimed in 2000. This isn't surprising because even the most efficient hobby motors available don't achieve an Isp much over 200. Compare this to the Shuttle Main Engines, which start at around 450 Isp at sea level and rise to over 500 in the vacuum of space.
I believe that for anyone to reach the 200km mark of the expired CATS prize with a 3 stage amature rocket would require 1) Lightweight yet very strong construction, 2) no wasted space...not only 'minimum diameter' but 'minimum length' as well, and 3) improved hobby motor technology capable of producing an Isp of at least 250.
A Lox/Kerosene bipropellant engine can easily reach 250 and then some, but liquid moters are highly complex devices, especially the super-powerful gas-turbines used to inject the fuel/oxidizer mixture into the combustion chamber at the high compression levels required. I takes millions of dollars and a full team of engineers to make such an engine, so thats out.
I had toyed with the idea of a pulsejet/rocket combo for the first stage, but most of the information I could find showed that to be impractical for an amature rocket. However, THIS PERSON may have a more viable solution...
My idea would be to use a ramrocket like ukrocketman suggests for the first stage, to take it to Mach 1 with a minimum amount of weight. Then the second stage would use something like an Aerocon bipropellant engine . This would boost it clear up to Mach 3+ and over 50km. Finally the 3rd stage, using a traditional composite motor, would boost it to around Mach 5+ and around 100km at engine burnout.
There is at least one major flaw in what I described above: Namely...how to ignite the second stage. The 3rd stage could be ignited using an altimiter, but that would be very tricky, since it would be difficult to accurately predict the altitude at which the second stage would burn out. I'm sure others on this forum will be able to point out additional major problems with this concept as well, heh.
However, my dream rocket (which I'll never build...but maybe somebody will
) would go something like this:CATS went unclaimed in 2000. This isn't surprising because even the most efficient hobby motors available don't achieve an Isp much over 200. Compare this to the Shuttle Main Engines, which start at around 450 Isp at sea level and rise to over 500 in the vacuum of space.
I believe that for anyone to reach the 200km mark of the expired CATS prize with a 3 stage amature rocket would require 1) Lightweight yet very strong construction, 2) no wasted space...not only 'minimum diameter' but 'minimum length' as well, and 3) improved hobby motor technology capable of producing an Isp of at least 250.
A Lox/Kerosene bipropellant engine can easily reach 250 and then some, but liquid moters are highly complex devices, especially the super-powerful gas-turbines used to inject the fuel/oxidizer mixture into the combustion chamber at the high compression levels required. I takes millions of dollars and a full team of engineers to make such an engine, so thats out.
I had toyed with the idea of a pulsejet/rocket combo for the first stage, but most of the information I could find showed that to be impractical for an amature rocket. However, THIS PERSON may have a more viable solution...
My idea would be to use a ramrocket like ukrocketman suggests for the first stage, to take it to Mach 1 with a minimum amount of weight. Then the second stage would use something like an Aerocon bipropellant engine . This would boost it clear up to Mach 3+ and over 50km. Finally the 3rd stage, using a traditional composite motor, would boost it to around Mach 5+ and around 100km at engine burnout.
There is at least one major flaw in what I described above: Namely...how to ignite the second stage
. The 3rd stage could be ignited using an altimiter, but that would be very tricky, since it would be difficult to accurately predict the altitude at which the second stage would burn out. I'm sure others on this forum will be able to point out additional major problems with this concept as well, heh.
