Model rocket
A model rocket is a flight model that is propelled with the help of a rocket engine. Model rocket building is a well-defined term for the safe, non-professional operation of rockets in the hobby area, which are manufactured according to certain criteria and are operated with industrially manufactured and tested motors. The criteria are set out in a safety code (see below). Rockets for professional use or with self-built engines do not fall under the term model rockets.
Definition of terms
A model rocket is a term for a flying rocket for hobby users that conforms to certain internationally established standards. These are described in the model rocket safety code , which in turn is based on the American NFPA Code 1122, and are defined, among other things, by:
- Weight of the rocket under 1.5 kg
- Motors with less than 320 Ns total impulse or 125 grams of pyrotechnic propulsion mass
- Use of light and fragile components
- No metal parts in the supporting structure
- Use of commercially available propellants, no self-made
The demarcation is primarily used for safety compared to other non-professional rocket types, since model rocket flight is considered extremely safe and accidents can hardly occur if the guidelines are observed. Hobby rockets that do not meet these definitions can therefore not be called model rockets. They are then considered, for example, as an amateur rocket (with the subtype experimental rocket ) or as a high-power rocket . For example, high-power rockets are often confused with model rockets, although they do not meet the criteria of model rockets and have a higher risk of accidents.
Historical development of model rocket construction
The term model rocket (model rocket) emerged in the 1950s, the first time in the United States. Model rockets were offered there as a safe hobby alternative to amateur or experimental rockets. Especially in the 1950s, in the wake of the general enthusiasm for space travel, many mostly young hobbyists experimented with self-made engines and models. Accidents often occurred; Model rockets should therefore be a safe alternative. That is why the National Association of Rocketry (NAR) was founded in the USA at the end of the 1950s and created a security code. He imposes restrictions on the term model rocket , such as the weight and the use of building materials (lightweight material such as cardboard and balsa wood, without metal, only use of prefabricated and tested motors) with the aim of avoiding accidents. The code has therefore been adopted by many clubs, associations and organizations (such as the FAI ) worldwide.
Since the 1990s, more powerful engines based on composite fuel have also been available. The weight limit for model rockets in the safety code was therefore raised from 500 grams to 1.5 kg after several safety tests.
Function, drives and construction
Model rockets with propellants based on solids can reach heights of several thousand meters. There are also other types of rockets that are similar to model rockets such as those powered by water pressure ( water rockets ) or compressed air ( compressed air rockets ). They are inferior to the models equipped with solid-fuel motors in terms of performance, but still reach altitudes of a few hundred meters. Rockets with hybrid propulsion or using liquid propellants have also been realized. However, because of the complicated technology used, they are reserved for professional hobbyists and because of their increased weight (see definition of model rockets) they no longer fall into the category of model rockets.
Black powder-based solid model rocket motors are manufactured and sold in large quantities. The world's leading manufacturer in this field alone, Estes Industries from the USA, states that it produces around 10 million engines per year. According to the manufacturer, 315 million engines have been produced in the 50 years or so since the company was founded. Despite this high number, the introduction and observance of the safety code has never resulted in a serious accident, which speaks for the astonishingly good safety record of the hobby.
After their flight, model rockets land softly on the earth with the help of a recovery system (usually a parachute or a torrent ). You can be made ready for a new flight by changing the propellant.
Various experiments can be carried out with model rockets: For example, one can try to lift an egg into the air with the help of a suitable model rocket (egg lofting) and bring it back to earth in one piece. Other model rockets, such as B. the Astrocam and the Oracle allow the self-production of aerial photographs. There are also flight competitions for model rockets. Either the altitude or the duration of the flight is measured depending on the propellant used and the type of model (see model rocket sports ).
Model rockets are offered by the relevant manufacturers (e.g. Estes ) as finished models and as a kit, although there are also very small model rockets, the so-called Micro-Maxx rockets. The complete in-house development of model rockets is also possible. To start with, a commercially available starter set is recommended, which already contains all the necessary components, from the rocket to the launch device.
Statutory Regulations (Germany)
- Freely available rocket motors contain a maximum of 150 g of fuel and may only be given to people over the age of 18.
- A permit according to Section 27 Explosives Act (so-called P2 certificate (T2 certificate)) is required to acquire and use more powerful engines. Handling includes storing, using, destroying and moving.
- For model rockets with more than 20 g of fuel mass, an ascent permit must be applied for from the responsible state aviation authority (§21a LuftVO (operation of unmanned aviation systems and model aircraft requiring a permit)). A permit according to § 27 Explosives Act extends i. d. Usually also to auxiliary persons and trainees, as far as they act under the supervision of the license holder.
- Motors must be certified in accordance with the national usage regulations, for example through an approval from the Federal Institute for Materials Research and Testing (BAM). Many foreign motors are not certified in Germany, so even some motors with the CE mark cannot be used because they do not have national certification.
- The minimum age for handling these drives is 14 years and requires the supervision / consent of a parent or legal guardian.
- A sticker with the name and address of the owner must be attached to model rockets with a mass over 250 g.
Statutory provisions (Austria)
In Austria the following regulations apply to the flight of model rockets:
- In the case of starts without a permit, the propellant mass must not exceed 50 grams (class 2).
- A maximum altitude of 150 meters above ground (uncontrolled airspace) may not be exceeded without a permit. Permits are issued by the responsible aviation authority ( Austro Control ) and are subject to a fee.
- Since these height restrictions can vary depending on the location (e.g. near the airport), the relevant information must always be obtained from the responsible aviation authority (Austro Control).
Statutory provisions (Switzerland)
In Switzerland, air and pyrotechnic regulations apply to model rockets.
Air law
In Switzerland, model rockets are not classified as aircraft but as ballistic projectiles. Depending on the airspace, different maximum altitudes apply:
- Within air space G: a maximum of 600 m above ground. A NOTAM (Notice to Airmen) is required at over 600 m .
Model rockets are expressly not allowed to be flown:
- Within a CTR of an airport (near an airport), except with the express permission of the flight controller.
- In an airway (AWY)
The CTRs and AWYs can be found on the aviation map of Switzerland, which can be obtained from the Aeroclub . The visual flight rules apply to model rocket flight: The rocket pilot is responsible for ensuring that his rocket does not fly into the clouds and that it is only launched when there is sufficient horizontal visibility. It is expressly prohibited to take off if an airplane or other aircraft is nearby or could enter the flight path. The rules are analogous to those of the model rocket safety code .
Films on the subject
The American drama October Sky , a film adaptation of Homer Hickam 's autobiographical novel Rocket Boys , is about a boy who discovered an interest in model rocket building in the 1950s and was met with skepticism in his hometown of Coalwood in West Virginia . Finally, the main character (played by Jake Gyllenhaal ) wins a science fair with the rocket construction project and thus begins his scientific career.
See also
literature
- Oliver Missbach: Flying model rockets, self-built . Construction, take-off, flight, landing. Edition Countdown, Munich 2001, ISBN 3-89811-855-X ( website [accessed February 2, 2009]).
- Mark Canepa: Modern High-Power Rocketry 2 , A comprehensive illustrated guide to building, launching, and recovering High-Power Rockets. Trafford.
Web links
Individual evidence
- ↑ Missile categories ( Memento from October 19, 2013 in the Internet Archive )
- ↑ Security Code
- ^ List of NFPA Codes and Standards. Retrieved October 24, 2019 .
- ↑ Legal regulations in Switzerland