Model Rocketry! First Steps.

After hearing about a friend of mine who recently planned a date that involved home made model rockets, I decided to delve a little deeper into the study myself. Can I just say, building homemade rockets is the greatest date idea I have ever heard? I mean, it combines nerdy endeavors with excitement, hands on activities, and the opportunity to show off that you know how to make hot gasses expel at hundreds of feet per second out the end of a PVC pipe. Yeah, someday I'm going to try this.

In the mean time, I'm going to do what I do best, and delve into a little self study.

There are two main types of solid fuel I plan to use. The first is known as "Candy Rocket", because its primary fuel source is sugar. The next, more powerful, rocket fuel is known as Ammonium Perchlorate Composite Propellant (APCP). It is, in fact, the same solid rocket fuel used in the shuttles Solid Rocket Boosters (SRB). It's more complicated to build and use, but is significantly more effective than a candy rocket.

One thing at a time...

For a candy rocket, there are a few important ingredients..

• Potassium Nitrate. Used as the oxidizer. There may be better oxidizers out there, but this is the one I am most familiar with. It's also easy to obtain.
• Sucrose/charcoal. Gotta have a fuel. The sugar also acts as a great binding agent.
• Iron oxide/Sulfur, burn rate catalysts, increases the rate of combustion. Leading to a greater acceleration. Unfortunately, this also means the motor's burn time is reduced. Over all performance may not be affected. 
• Aluminum powder may enhance performance of the rocket by acting as an "opacifier", or to increase the exhaust temperature.

To construct the body of the rocket I plan to use PVC tubing, with a caste nozzle made out of water putty. Water putty probably isn't the best material for the job, as it isn't designed to hold up to temperatures such as are found inside the combustion chamber of a rocket engine, but from other peoples experience, it seems to work just fine. Lots of great info on the construction method can be found here.. https://sites.google.com/site/airwavershr/Home/rocketry. Kitty litter is supposed to be a great way to cap the end of the fuel. I'm not sure how that's supposed to work, but I'm willing to give it a try.

One of the key goals of this model rocketry endeavor is the telemetry module. It would be so cool to be able to capture 6axis telemetry, and analyze it post-flight. There are four main components that make up the telemetry module. they are:

• 6axis MEMS device
• nrf24L01+ wireless module
• SD card
• msp430 microcontroller (It's what I had laying around!)
• Battery

Each of these components will be housed in the nose cone of the rocket. They somehow need to be protected from the inevitable impact with the ground. It may be unrealistic without an ejection charge, and a parachute, but I'm going to try. A Styrofoam cone with steel bailing wire reinforcements aught to be enough to withstand the impact. If the components could be housed partially in the PVC body, and the reinforcements transferring most of the shock to the body, the likely hood that the components will survive is increased.

The range on the wireless module might be somewhat limited when it comes to highflying rockets. In which case an EEPROM or SD card to store the telemetry may proved a better solution. It's not as sexy as live data though. An ejection charge and chute may be required for easy recovery.