Amateur rocket motor classification
Encyclopedia
Motors for model rocket
s, high powered rocket
s, and amateur rockets
are classified by total impulse into a set of letter-designated ranges, from A (the smallest, though 1/2, 1/4, and 1/8-A motors are also available), up to O as the largest. A is from 1.26 newton-second
s to 2.5 N·s, and each class is then double the total impulse of the preceding class, with B being 2.51 to 5.00 N·s. Engines classified beyond O are in the realm of amateur rocketry
. In this context, the term amateur refers to the rocketeer's independence from an established commercial or government organization.
The impulse designation for a specific motor is based on the alphabetic code. For example, the letter (M) would represent the total impulse of between 5,120.01 and 10,240.00 N·s of impulse.
, high-powered motors (above 160 newton seconds) are restricted by industry convention to purchasers who possess the requisite certification, though this is not a legal restriction. In the United States of America, the two recognized organizations that provide high-power certifications are Tripoli Rocketry Association
and the National Association of Rocketry
, both of these organizations have three levels of certification which involves building progressively more complex and higher powered rockets and taking a test of safety rules and regulations. The U.S. government regulatory documents surrounding high-powered rocketry are FAA FAR Part 101 and NFPA 1127. In Canada, the Canadian Association of Rocketry
has a 4 step certification process, but all three organizations accept the other's certifications if a flyer shows up at a high-power launch and wishes to fly under their sanction. Some states restrict the maximum impulse to a G motor. The United Kingdom Rocketry Association
employs a similar 3-level system as Tripoli and NAR, and UK fliers may require governmental approval to obtain larger motors or to possess large quantities of them.
Level 1 certification qualifies you to purchase and use H and I engines, Level 2 certification J, K, and L engines and Level 3 certification M, N, and O engines. Note: Canada adds another step in between, and has a Level 4 which is the same as US Level 3.
established laws after September 11, 2001, which required that an individual must hold a Low explosive Users Permit (LEUP) to have a high-powered motor in their possession. Following a 9-year long lawsuit brought by TRA and NAR against the BATFE, these laws were overturned in a federal court in 2009, and U.S. citizens no longer require governmental approval to purchase APCP solid rocket motors.
Model rocket
A model rocket is a small rocket that is commonly advertised as being able to be launched by anybody, to, in general, low altitudes and recovered by a variety of means....
s, high powered rocket
High powered rocket
High-power rocketry is a hobby similar to model rocketry. The major difference is that higher impulse range motors are used. The National Fire Protection Association definition of a high-power rocket is one that has a total weight of more than 1500 grams and contains a motor or motors...
s, and amateur rockets
Amateur rocketry
Amateur rocketry, sometimes known as amateur experimental rocketry or experimental rocketry is a hobby in which participants experiment with fuels and make their own rocket motors, launching a wide variety of types and sizes of rockets...
are classified by total impulse into a set of letter-designated ranges, from A (the smallest, though 1/2, 1/4, and 1/8-A motors are also available), up to O as the largest. A is from 1.26 newton-second
Newton-second
The newton-second or newton second is the derived SI unit of impulse and momentum. It can also be expressed as the kilogram metre per second...
s to 2.5 N·s, and each class is then double the total impulse of the preceding class, with B being 2.51 to 5.00 N·s. Engines classified beyond O are in the realm of amateur rocketry
Amateur rocketry
Amateur rocketry, sometimes known as amateur experimental rocketry or experimental rocketry is a hobby in which participants experiment with fuels and make their own rocket motors, launching a wide variety of types and sizes of rockets...
. In this context, the term amateur refers to the rocketeer's independence from an established commercial or government organization.
The impulse designation for a specific motor is based on the alphabetic code. For example, the letter (M) would represent the total impulse of between 5,120.01 and 10,240.00 N·s of impulse.
Motor impulse by Class
Class Total Impulse
(Metric Standard)Total Impulse
(Imperial Standard)A 1.26-2.50 N·s 0.29-0.56 lbf·s B 2.51-5.00 N·s 0.57-1.12 lbf·s C 5.01-10.00 N·s 1.13-2.24 lbf·s D 10.01-20.00 N·s 2.25-4.48 lbf·s E 20.01-40.00 N·s 4.49-8.96 lbf·s F 40.01-80.00 N·s 8.97-17.92 lbf·s G 80.01-160.00 N·s 17.93-35.96 lbf·s H 160.01-320.00 N·s 35.97-71.92 lbf·s I 320.01-640.00 N·s 71.93-143.83 lbf·s J 640.01-1280.00 N·s 143.84-287.65 lbf·s K 1,280.01-2,560.00 N·s 287.66-575.30 lbf·s L 2,560.01-5,120.00 N·s 575.31-1150.60 lbf·s M 5,120.01-10,240.00 N·s 1150.61-2301.20 lbf·s N 10,240.01-20,480.00 N·s 2301.21-4602.40 lbf·s O 20,480.01-40,960.00 N·s 4602.41-9204.80 lbf·s P 40,960.01-81,920.00 N-s 9204.81-19409.60 lbf·s Q 81,920.01-163,840.00 N-s 19409.61-38819.20 lbf·s R 163,840.01-327,680.00 N-s 38819.21-77638.40 lbf·s S 327,680.01-655,360.00 N-s 77638.41-155276.80 lbf·s T 655,360.01-1,310,720.00 N-s 310553.81-621107.2 lbf·s U 1,310,720.01-2,621,440.00 N-s 621107.21-1242214.40 lbf·s V 2,621,440.01-5,242,880.00 N-s 1242214.41-2484428.80 lbf·s W 5,242,880.01-10,485,760.00 N-s 2484428.81-4968857.60 lbf·s X 10,485,760.01-20,971,520.00 N-s 4968857.60-9937715.2 lbf·s
Governmental regulation
In many countries, the sale, possession, and use of model rocket motors is subject to rules and regulations. For example, in the United StatesUnited States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, high-powered motors (above 160 newton seconds) are restricted by industry convention to purchasers who possess the requisite certification, though this is not a legal restriction. In the United States of America, the two recognized organizations that provide high-power certifications are Tripoli Rocketry Association
Tripoli Rocketry Association
The Tripoli Rocketry Association is one of the two major organizing bodies for high power rocketry in the United States. It was founded in 1964 in the Pittsburgh, PA region as a high school science club, integrating both rocketry and space science...
and the National Association of Rocketry
National Association of Rocketry
The National Association of Rocketry is the governing body for the sport/hobby of model rocketry in the United States. It was established in 1957 by Orville Carlisle and G. Harry Stine and is currently headed by Trip Barber. It is the oldest and largest model rocketry governing body in the...
, both of these organizations have three levels of certification which involves building progressively more complex and higher powered rockets and taking a test of safety rules and regulations. The U.S. government regulatory documents surrounding high-powered rocketry are FAA FAR Part 101 and NFPA 1127. In Canada, the Canadian Association of Rocketry
Canadian Association of Rocketry
The Canadian Association of Rocketry - L'Association Canadienne De Fuséologie is a Canadian federal not for profit self-supporting association and governing body representing amateur/model rocketeers across Canada...
has a 4 step certification process, but all three organizations accept the other's certifications if a flyer shows up at a high-power launch and wishes to fly under their sanction. Some states restrict the maximum impulse to a G motor. The United Kingdom Rocketry Association
United Kingdom Rocketry Association
The United Kingdom Rocketry Association is an enabling body set up to promote and represent high power, medium power and model rocketry in the United Kingdom for educational, recreational and amateur research purposes....
employs a similar 3-level system as Tripoli and NAR, and UK fliers may require governmental approval to obtain larger motors or to possess large quantities of them.
Level 1 certification qualifies you to purchase and use H and I engines, Level 2 certification J, K, and L engines and Level 3 certification M, N, and O engines. Note: Canada adds another step in between, and has a Level 4 which is the same as US Level 3.
BATFE Lawsuit
The U.S. Bureau of Alcohol, Tobacco, Firearms and ExplosivesBureau of Alcohol, Tobacco, Firearms and Explosives
The Bureau of Alcohol, Tobacco, Firearms and Explosives is a federal law enforcement organization within the United States Department of Justice...
established laws after September 11, 2001, which required that an individual must hold a Low explosive Users Permit (LEUP) to have a high-powered motor in their possession. Following a 9-year long lawsuit brought by TRA and NAR against the BATFE, these laws were overturned in a federal court in 2009, and U.S. citizens no longer require governmental approval to purchase APCP solid rocket motors.
External links
- Aerotech website
- Estes website
- National Association of Rocketry (NAR) - Model Rocketry and High-Powered Rocketry Certifications
- Tripoli Rocketry Association (TRA) - Amateur High-power rocketry Certifications)
- Canadian Association of Rocketry (CARWeb) - Model Rocketry and High-Powered Rocketry Certifications in Canada
- United Kingdom Rocketry Association (UKRA) - Promoting high power, medium power and model rocketry in the United Kingdom for amateur research, educational and recreational purposes