Rocket questions

[liitonen]

First I say that I am sorry about my bad English.

Then the questions:
1. What are the different types of rockets?
2. What are the classes in this hobby?
3. what is the "official name" of this hobby in English?

I thank for the answers forward.

[Ray]

First I say that I am sorry about my bad English.

Then the questions:
1. What are the different types of rockets?

There are many, many different types of rockets. They all consist of a body tube, nose cone (of some nature), fins and a motor(s). The thing all the rockets in the hobby have in common is that they have only passive guidance. The fins provide stability to the flight much the same way a weather vane does.

2. What are the classes in this hobby?

There are generally three classes. Models or low power, meaning a rocket that is light weight, and uses small motors, usually A-E. Mid power, meaning a rocket that is a bit more heavy and uses F and G motors. And high power, a rocket that uses at least an "H" motor. High power rockets can be VERY large, and use VERY large motors. I know of one rocket that weighed over 600 lbs (272 kg) and flew on 4 "O" class motors. The motors had over a metric ton of thrust for around 5 seconds...information about the class of motor can be found here and here.

3. what is the "official name" of this hobby in English?

Many names for it in english. Hobby or ameteur rocketry is the most common.

[liitonen]

Thanks

[Tom]

Not to be the devils advocate here Ray, but I know of an effort to have active guidance, or at least stability in a rocket platform fom the MARS group. Also liitonen, in case you are interested, there are also a few types of propulsion, ranging from hybrid motors, which tend to use a plastic or paper fuel grain with a tank of nitrous oxide for the oxidizer, to Ammonium Perchlorate (AP) Motors, which tend to have the AP mixed with a rubber /binder, and all the way down to Black Powder/Gun powder motors, commonly found in most hobby shops under the Estes brand.

Tom

[Ray]

Yes, you are right on the guidance systems for rockets. I try to steer people away from this activity...it sounds too much like a missile. It's not a big step to go from active stability, or roll control to active guidance. The jump from there to targeting is bigger, but not insurmountable. There is already too much attention paid to the rocketry community by the government. I just don't want to attract more.

There are lots of motor designs...AP, Hybrid and Black powder are all commercially available. KN, PSAN, LOX, and Micro Grain (zinc/sulfur) and the others are all pursued by amateurs in the hobby. There really isn't any end to the motor configurations pursued by the Experimental community.

I have a friend that has a unique hybrid design he is intending to market. Lots of static testing, and around 10 flights. It'll be the first hybrid that is capable of staging without any special setup. I saw a 2 stage flight with this motor, but we weren't able to recover the bird...it went out of sight. His motor is regen cooled, including the nozzle, and typically uses black nylon as a fuel grain. He is currently working to get the motor commercially certified by NAR and Tripoli, so they can be flown at commercial launches.

[Tom]

Wow, that sounds like quite a nice motor, do you have any more information on it? Or is it all a bit hush-hush till its's more widly known as his work? Sounds as if it might be expensive though. The 3 motors I mentioned are the ones that I seem to find on the flight line at rocketry meets, I don't think the local has ever seen a liquid on their flight line, a shame, though we have had various EX stuff IIRC.

[Ray]

Well I can't go into real detail on the motor, he is working on a patent at the same time. Disclosure at this point could really disrupt what he is trying to do with it.

In short, the combustion chamber is concentric with the oxidizer tank, through clever design this allows the regen cooling. Control of the nitrous flow into the chamber is unique and doesn't use the nylon tube burning away (U/C valve) other systems use. The motor lights as fast as a Black Powder motor and has higher average impulse than similar sized Hybrids. Everybody that has seen a flight, or a static test says its the most unique hybrid they have ever seen.

Once he gets down the road a bit further with the patent, I'll share more details.

The motor won't be that expensive, other than the nozzle all the machining is very simple. Per launch cost is very low, as with all hybrids.