National Association of Rocketry Model Rocketry Safety Code (Aug 2012)

This is a copy of the NAR Model Rocket Safety Code and is only listed here for referance. The original document can be found at http://www.nar.org/safety-information/model-rocket-safety-code/ Please refer to this link for the most up to date version of the Model Rocket Safety Code.

Model Rocket Safety Code
Effective August 2012

  1. Materials. I will use only lightweight, non-metal parts for the nose, body, and fins of my rocket.
  2. 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.
  3. 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.
  4. 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.
  5. 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.
  6. 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.
  7. 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.
  8. 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.
  9. 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.
  10. 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.
  11. Recovery Safety. I will not attempt to recover my rocket from power lines, tall trees, or other dangerous places.
LAUNCH SITE DIMENSIONS
Installed Total Impulse (N-sec) Equivalent Motor Type Minimum Site Dimensions (ft.)
0.00–1.25 1/4A, 1/2A 50
1.26–2.50 A 100
2.51–5.00 B 200
5.01–10.00 C 400
10.01–20.00 D 500
20.01–40.00 E 1,000
40.01–80.00 F 1,000
80.01–160.00 G 1,000
160.01–320.00 Two Gs 1,500

Revision of August, 2012

Rocketry Crib Sheet (Finding height & other math)

This is a quick crib sheet to help you as you build model rockets. There is much more to be found on the Internet. If you find a helpful link please share it in the comments section below.

To Convert Inches (in) to Centimeters (cm):       (in) * 2.54 = (cm’s)

Example: 5 in * 2.54 = 12.7 cm

To Convert Feet (ft) to Meters (m):                     (ft) / 3.281 = (m)

Example: 7 ft / 3.281 = 2.1335 m

To Convert Meters (m) to Feet (ft):                     (m) * 3.281 = (ft)

Example: 30 m * 3.281 = 98.43 ft

Added 1-19-19, for a guide to build your own altitude tracker using a protractor review this guide we put together.

Updated 7-20-16, some of the links below have changed the content and no longer include the simple altitude calculation so we have added it below.

To calculate the height of a right triangle:         tan(angle) * distance = height
(yes, use a calculator to find the tangent)

Example: tan(59°) * 100 feet = 166.43 feet

Example: Sandy is launching her rocket. Her cousin, Tim, is standing 300 feet away with a protractor when Sandy launches her rocket. The protractor angle reads 127° when the rocket reaches its highest point, known as apogee. Tim knows he needs to subtract 90° from the angle on the protractor to get the correct angle. How high did the rocket go?

tan(127° – 90°) * 300 feet = height Rocket Height
Simplify
tan(37°) * 300 feet = height
Simplify
~0.75355 * 300 feet = height
Simplify
~226.07 feet = height

Sandy’s rocket flew about 226.07 feet in the air. (We round off the extra digits after .07)

Finding a side in a right-angled triangle

https://www.mathsisfun.com/algebra/trig-finding-side-right-triangle.html

How to measure model rocket altitude

http://www.hobbizine.com/rocketaltitude.html

Rocket Center of pressure calculator

http://physics.gallaudet.edu/tools/rocketcop.html

Rocket Altitude Calculator

http://www.unm.edu/~tbeach/flashstuff/RocketAltitudeFixedSize.html

Determine Maximum Altitude

http://exploration.grc.nasa.gov/education/rocket/rkthowhi.html

OpenRocket Model Rocket Simulator – Freeware

http://openrocket.sourceforge.net/

Altitude Tracking

http://quest.arc.nasa.gov/space/teachers/rockets/act9.html

Flight Simulator Programs (List of different software)

http://www.thrustcurve.org/simulators.shtml