Egg-O-Naut

General Rocket Construction
For information on general bottle rocket design, go to Bottle Rocket. Egg-O-Naut specific things will be posted below.

NASA Rocket Basics

NASA Rocket Simulators

Ideas
Here are some ideas that starpug and I came up with one day on the AJAX chat, I’m not sure how much help they’ll be, but they should help a little.

Bottles to Use
It looks like 2 liter bottles this year, so probably you should go with Pepsi product bottles. It can be easier to attach fins to these because they have straight sides. Coca-Cola is fazing in bottles with curved sides, you probably wanna avoid these as they are hard to attach fins to and possibly less aerodynamic.

The scoring system for 2010 puts great emphasis on the condition of the egg. The recovery system was extremely important because with these rules, a well-built rocket with a broken egg will almost definitely be beaten by a poorly-built rocket with an intact egg.

Parachute
It seems like the best safety device would be a parachute, with padding around the egg in case of the parachute failing. A larger parachute is usually better, unless you build it to large. A 2 to 4 foot diameter should be large enough, although if you can use a bigger parachute you are more likely to catch up drafts but are going to have a harder time fitting it in the nose cone. I would suggest using a thin plastic, such as thin drop cloth, but Mylar or even plastic/garbage bags will also work. By attaching the parachute to the egg but not the rocket itself, when it deploys it should separate the egg from the bottle, which the current scoring gives several bonus points for. The winning time last year at Nationals was 72 seconds with bonuses. With the increase to 2 liter bottles these times can only increase, so it would be wise to aim for a minute and up to be competitive at nationals.

Cushioning
For cushioning around the egg, from what I’ve built so far, bubble wrap works well, and a foam or cardboard flap to cover one end of the bottle. You could also use layered paper, a liquid (probably harder and will reduce time due to added weight, but its an idea), or you could suspend the egg using strings or bungee cords (the strings would have to be pretty tight). You could also use no padding and simply use a plastic bag to hold the egg if you were confident your parachute will deploy.

Separating The Egg From the Rocket
From what the rules say having the egg capsule leave the rocket is almost a must, it reduces weight you have to get safely to the ground, and it adds 3 seconds to your time. A good way to achieve this would be a cone that falls off and pulls the parachute and egg chamber with it, or just having the egg chamber fall off on its own.

Other Ideas
You could also use a backslider, but a well built parachute will almost always beat a backslider.

Links
Bottle Rocket

North Carolina 2007 Results-