The amateur rocketry is a hobby that involves making models of rockets and, most often, to make them fly. The modeller will focus on “real” space rockets , which he will make as faithful reproductions as possible. The “technician”, meanwhile, will focus on creating and flying rockets.
Of course, it is possible to combine these two activities, reproduction and flights.
It is the total onboard power (see the engine characteristics below), expressed in newton x second which will determine the category of the rocket. We consider three categories of powers for rocket modeling 1. The low-power rockets embark engines of categories A to D whose power does not exceed 20 Ns The medium-power rockets board engines up to G for a total of 160 Ns Beyond this power the rocket is said high power and can be powered by H and higher motors. It is always the total embedded capacity, expressed in newton x second which will condition the category of the rocket. For a multi-stage rocket or cluster of engines, we must add the full power of its engines to define the category to which it belongs.
A fourth category known as experimental exists for very high power propulsion devices. The GoFast rocket, for example, of the CSXT , which holds the first altitude record for an amateur rocket to reach the space was made on. This type of rocket belongs to the experimental category. The rules for launching model rockets meet different standards in different countries.
Rules in North America
In North America, for models up to medium power, the launch is free and self-regulated. The materials are freely available. Launches are also free, subject to local legislation (prohibition of shooting on the island of Montreal for example) and application for authorization to the owner of the launching pad. It is only recommended to join one of the representative organizations and to follow the code of good conduct that they set.
The oldest of these associations is the “NAR” (National Association of Rocketry) 2 manages this activity in the United States since 1957 and counted 90,000 members since its birth 3 .
In Canada, the “CAR” or Canadian Association of Rocketry is responsible for representing astro-modellers 4 . It is the CAR that is delegated to the amateurs of Quebec.
These organizations are delegated regulatory actions and are interlocutors for the public authorities. They offer registered members third-party liability insurance. They demand from their members a strict application of their code of conduct 5 . This code of conduct is identical for the CAR and the NAR
The launch of high-powered rockets is subject to certification in North America. Four levels of certification – corresponding to various powers – are possible. This certification may be issued by NAR or CAR 6 . Complementary organizations federate certified users for high power. The most widespread around the world is the “TRA” or Tripoli Rocketry Association 7, which has been in charge of high-powered astronomy since the early 1960s. It has nearly 12,000 registered members worldwide. It exists in the United States, Canada (with a prefecture in Quebec), Australia, Israel as well as in the prefectures of 8 European countries including France 8 .
These large organizations support highly structured clubs and intervene so that the legislator regulates the activity as little as possible while promoting a methodology and a safe practice the realization of model rockets propelled by commercial engines or experimental engines. The Nar for example regularly intervenes with the regulator to limit the classification of propulsion products in dangerous products 9 .
Rules in France
The Ministry of the Interior issued a circular ofprohibiting the construction and implementation of non-controlled powder rocket engines, with the stated aim of reducing the number of accidents resulting from the attractiveness of this activity. The control of these activities was then entrusted to the National Center for Space Studies , CNES, then nascent. The CNES asked the National Association of Science Clubs ( ANCS ) in famous 1969National Association of aerospace clubs ( ANCS ) and National Youth Technical Sciences Association ( ANSTJ ), and since 2002 entitled Planète Sciences, to follow these clubs in the development of their projects, to coordinate national actions and to train animators.
Since the publication of Decree No. 2008-1281 of 8 December 2008 on the conditions of publication of instructions and circulars NOR: PRMX0829186D since the 1 st May 2009, the circular is repealed. The prohibition above is no longer in effect.
In 1985 , the important development of the aerospace activities of young people who can practice these activities from 8 years, leads the Ministry of the Interior to disseminate a new circular formalizing the role of help, monitoring and control of Planète Sciences with young practitioners in experimental aerospace activities.
Astromodelling allows to implement the following technologies:
- Simulations of flight behavior;
- Construction ;
- Physical: gravity , aerodynamics , mechanics ;
- Electricity (ignition system);
- Electronics ;
- Meteorology ;
- Embedded techniques.
Also in this activity:
- An experimental approach;
- Project management.
Characteristics of the engines
The rocket engines in models used can be approved or experimental and use different technologies. They are classified by a letter according to their momentum in newton.second , that is to say the total force which they exert during the complete duration of their operation.
|Class||Total impulse (Ns)|
|K||1280.01 to 2560.00|
|The||2560.01 to 5120.00|
|M||5120.01 to 10240.00|
|NOT||10240.01 to 20480.00|
|O||20480.01 to 40960.00|
|P||40960.01 to 81920.00|
|Q||81,920.01 to 163,840.00|
|R||163,840.01 to 327,680.00|
|S||327,680.01 to 655,360.00|
|T||655,360.01 to 1,310,720.00|
|U||1,310,720.01 to 2,621,440.00|
|V||2,621,440.01 to 5,242,880.00|
|W||5,242,880.01 to 10,485,760.00|
|X||10,485,760.01 to 20,971,520.00|
Orders of magnitude
Here are the characteristics of an average rocket:
- Height: 60 cm
- Diameter: 3 to 4 cm
- Mass: 200 grams
- 1 powder motor
- 1 floor
- Altitude reached: 250 m
- Flight time: 20 s
- Maximum speed: 200 km / h
But it is possible to make very different rockets:
- Height: 15 cm to 1.50 m
- Diameter: 1 to 8 cm
- Mass: 20 grams to 1 kg
- 1 to 4, 5 … engines
- 1 to 3 floors
- Altitude reached: 25 to 800 m
- Flight time: 0 to 1 min
- Maximum speed: 300 to 400 km / h
It is quite possible to build and fly rockets with very different characteristics; these are only orders of magnitude.
- Scale models
- Aerial modelism
- Water rocket
- Micro rocket
- October’s Sky , a film based on an autobiographical novel by Homer Hickam, traces the adventures of young pyrotechnic rocket enthusiasts to Coalwood , a mining town in West Virginia , shortly after Sputnik 1 was launched in October 1957 .
- ( En ) Planet Science
- ( fr ) http://tripoli.france.free.fr/
- ( fr ) http://alcems.free.fr/
- ( En ) ESO Association (ESTACA Space Odyssey)
- ( en ) www.astromodelisme.com
Notes and references
- ↑ Definition of powers
- ↑ ( in ) ” National Association of Rocketry ” , nar.org (accessed 18 July 2011 )
- ↑ Presentation of the NAR
- ↑ ( in ) ” Canadian Association of Rocketry ” , http://www.canadianrocketry.org/ (accessed 18 July 2011 )
- ↑ Code of Conduct CAR
- ↑ description of certification levels by the CAR
- ↑ ( in ) ” Tripoli Rocketry Association ” , Tripoly.org (accessed 18 January 2009 ) , High power rocketry
- ↑ Prefecture Tripoli France
- ↑ Objectives and actions of the NAR