Model Rocketry Project
Construction:
Engine Analysis: Newton's third law states that for every action, there must be an equal and opposite reaction. This is key to a rocket's success; as hot engine gases are expelled downward, they exert an upward force on the rocket.
Different engines have different specs in order to give them different flight characteristics. They are written in the format C6-3, E9-6, etc... The letter in front indicates the max impulse that the rocket is capable of. For example, A engines can produce a max of 2.50 N/s of impulse. The number doubles for each letter; therefore a B engine can produce 5.00 N/s of impulse, a C engine can produce 10.00 N/s and so on. The first number after the letter is the average thrust produced in Newtons, thus a C6-3 can produce around 6 Newtons of thrust. The final number is the delay in seconds from when the thrust stage stops until the ejection charge deploys. All of this data can be seen on a graph of the engine burn.
The correct engine choice for a rocket is absolutely essential to its success. For the wrong engine scenario, Caroline certainly picked the wrong engine! The D12-0 is a booster rocket, meaning it has no ejection charge. This rocket will fly up, hit its maximum height, and come straight down unassisted.
For my rocket, the V2 Semi-Scale, I will be using an E9-6.
For my rocket, the V2 Semi-Scale, I will be using an E9-6.
Flight Field: The following is a diagram depicting required space based on rocket altitude. For my rocket, I will need a 200' by 200' square.
Next is a satellite picture of the high school grounds. The 200' by 200' square will be highlighted.
Jobs of rocket team:
Trackers: the trackers follow the rocket's path through the sky and follow it to the landing spot.
Recovery Team: the recovery team is the group that actually retrieves the rocket.
Range Safety Officer: in charge of launch safety, safety during flight, and during recovery, as well as safety of everyone around.
As far as the actual launch is concerned, mine will likely be very affected by wind. It has large fins and a large body tube, meaning that it has lots of surface area. Wind will likely affect it at the bottom of the body.
Trackers: the trackers follow the rocket's path through the sky and follow it to the landing spot.
Recovery Team: the recovery team is the group that actually retrieves the rocket.
Range Safety Officer: in charge of launch safety, safety during flight, and during recovery, as well as safety of everyone around.
As far as the actual launch is concerned, mine will likely be very affected by wind. It has large fins and a large body tube, meaning that it has lots of surface area. Wind will likely affect it at the bottom of the body.
Rocket height can be calculated using a tool to measure the angle between the ground and the line of sight to the rocket, and the following trigonometric calculation. Trackers should stand approximately the rocket's max altitude away from the launch pad, and two people should work together to reduce error.
Safety: The NAR safety code
- Materials. I will use only lightweight, non-metal parts for the nose, body, and fins of my rocket.
- Motors. I will use only certified, commercially-made model rocket motors, and will not tamper with these motors or use them for any purposes except those recommended by the manufacturer.
- Ignition System. I will launch my rockets with an electrical launch system and electrical motor igniters. My launch system will have a safety interlock in series with the launch switch, and will use a launch switch that returns to the “off” position when released.
- Misfires. If my rocket does not launch when I press the button of my electrical launch system, I will remove the launcher’s safety interlock or disconnect its battery, and will wait 60 seconds after the last launch attempt before allowing anyone to approach the rocket.
- Launch Safety. I will use a countdown before launch, and will ensure that everyone is paying attention and is a safe distance of at least 15 feet away when I launch rockets with D motors or smaller, and 30 feet when I launch larger rockets. If I am uncertain about the safety or stability of an untested rocket, I will check the stability before flight and will fly it only after warning spectators and clearing them away to a safe distance. When conducting a simultaneous launch of more than ten rockets I will observe a safe distance of 1.5 times the maximum expected altitude of any launched rocket.
- Launcher. I will launch my rocket from a launch rod, tower, or rail that is pointed to within 30 degrees of the vertical to ensure that the rocket flies nearly straight up, and I will use a blast deflector to prevent the motor’s exhaust from hitting the ground. To prevent accidental eye injury, I will place launchers so that the end of the launch rod is above eye level or will cap the end of the rod when it is not in use.
- Size. My model rocket will not weigh more than 1,500 grams (53 ounces) at liftoff and will not contain more than 125 grams (4.4 ounces) of propellant or 320 N-sec (71.9 pound-seconds) of total impulse.
- Flight Safety. I will not launch my rocket at targets, into clouds, or near airplanes, and will not put any flammable or explosive payload in my rocket.
- Launch Site. I will launch my rocket outdoors, in an open area at least as large as shown in the accompanying table, and in safe weather conditions with wind speeds no greater than 20 miles per hour. I will ensure that there is no dry grass close to the launch pad, and that the launch site does not present risk of grass fires.
- Recovery System. I will use a recovery system such as a streamer or parachute in my rocket so that it returns safely and undamaged and can be flown again, and I will use only flame-resistant or fireproof recovery system wadding in my rocket.
- Recovery Safety. I will not attempt to recover my rocket from power lines, tall trees, or other dangerous places.