A model rocket launching

Model rocketry is a hobby similar to building model airplanes. In the hobby today, there are two distinct areas of rocket activity: amateur (or experimental) rocketry, and model rocketry (including high powered rocketry). Image File history File linksMetadata Download high-resolution version (732x1287, 590 KB)[edit] Summary radiov8 [edit] Licensing I, the creator of this work, hereby release it into the public domain. ... Image File history File linksMetadata Download high-resolution version (732x1287, 590 KB)[edit] Summary radiov8 [edit] Licensing I, the creator of this work, hereby release it into the public domain. ... A hobby is a spare-time recreational pursuit. ... Aircraft modeling or aeromodelling is a hobby that has been popular since the 1930s. ... A Redstone rocket, part of the Mercury program The traditional definition of a rocket is a vehicle, missile or aircraft which obtains thrust by the reaction to the ejection of fast moving fluid from within a rocket engine. ... A model rocket. ... High power rocketry is a hobby similar to model rocketry, with the major difference that the rockets flown are significantly larger. ...

Model and High Power Rocketry

Model rocketry and high power rocketry involve professionally-manufactured solid-fuel or hybrid liquid/solid fuel rocket motors. Since these motors are professionally designed and constructed, they are far safer than motors produced by individuals for use in amateur or experimental rocketry. The motors also are tested and certified by the National Association of Rocketry or the Tripoli Rocketry Association and come in standardized sizes and powers. The National Association of Rocketry (NAR) is the governing body for the sport/hobby of model rocketry in the United States of America. ... The Tripoli Rocketry Association is one of the two major organizing body for high power rocketry in the USA (See also: National Association of Rocketry. ...

Model Rocketry

According to the National Association of Rocketry safety code, model rockets are constructed of paper, wood, plastic and other lightweight materials. The code also provides guidlines for motor use, launch site selection, launch methods, launcher placement, recovery system design and deployment and more. Since the early 1960's, a copy of the Model Rocket Safety Code has been provided with most model rocket kits and motors. Model rocketry is a very safe hobby, provided precautions are taken as given in the safety code.

Model rocketry is enjoyed by many different levels of hobbyist, from grade-school children launching 3 inch (75 mm) tall models in the baseball field, to teams of adults launching 200 pound (100 kg) behemoths thousands of feet into the air. Model rocketry is often credited as the most significant source of inspiration for children who eventually become scientists and engineers. See National Association of Rocketry (NAR). The National Association of Rocketry (NAR) is the governing body for the sport/hobby of model rocketry in the United States of America. ...

The History of Model Rocketry

The model rocket, and more importantly, the model rocket engine, was designed in 1954 by Orville Carlisle, a licensed pyrotechnics expert, and his brother Robert, a model airplane enthusiast. They originally designed the engine and rocket for Robert to use in lectures on the principles of rocket powered flight. But then Orville read articles written in Popular Mechanics by G. Harry Stine about the safety problems associated with young people trying to make their own rocket engines. With the launch of Sputnik, many young people were trying to build their own rocket engines, often with tragic results. The Carlisles realized their engine design could be marketed and provide a safe outlet for a new hobby. They sent samples to Mr. Stine in January, 1957. Stine, a range safety officer at White Sands Missile Range, built and flew the models, and then devised a safety code for the activity based on his experience at the range. Orville Carlisle invented the hobby that would become known as model rocketry. ... Pyrotechnics are used in the entertainment industry The band Rammsteins stage acts centers largely around pyrotechnics Pyrotechnics is a field of study often thought synonymous with the manufacture of fireworks, but more accurately has a wider scope that includes items for military and industrial uses. ... Aircraft modeling or aeromodelling is a hobby that has been popular since the 1930s. ... The adolescent Internet. ... Sputnik 1 The Sputnik program was a series of unmanned space missions launched by the Soviet Union in the late 1950s to demonstrate the viability of artificial satellites. ... White Sands Missile Range (WSMR), formerly known as the White Sands Proving Grounds, is located in a valley between the Organ Mountains and the Sacramento Mountains of New Mexico. ...

The National Association of Rocketry was founded in 1957 to help promote not only the hobby, but to promote the safety of the activities related to model rocketry.

Estes Corporation was founded in 1957 and began marketing the new rocket engines and model kits.

Model rockets of special interest

Model rockets equipped with the Astrocam or Snapshot film camera or the Oracle digital camera, or with homebuilt equivalents, can be used to take aerial photographs. Model rockets with electronic altimeters can report and or record electronic data such as maximum speed, acceleration, and altitude. Astrocam launch The Astrocam is a model rocket with built in camera for making its own aerial photographs. ... Oracle is the name of a model rocket with built in digital camera, manufactured by Estes, for aerial photography. ...

Model rocketeers often experiment with rocket sizes, shapes, payloads, multistage rockets, and recovery methods. Some rocketeers build scale models of larger rockets, space launchers, or missiles. The second stage of a Minuteman III rocket A multistage (or multi-stage) rocket is, like any rocket, propelled by the recoil pressure of the burning gases it emits as it burns fuel. ...

High Power Rocketry (HPR)

As with model rockets, high-power rockets are constructed from lightweight materials. However, high-power rockets experience higher stresses during flight and must often be made of tougher materials, including fiberglass or carbon fiber.

High power model rockets are propelled by larger motors ranging from class H to O and can be up to 40 feet tall. Their motors are almost always reloadable rather than single-use in order to reduce cost. Recovery and/or multi-stage ignition may be initiated by small on-board computers, which use an altimeter or accelerometer for detecting when to ignite engines or deploy parachutes.

High powered model rockets can carry large payloads, including cameras and instrumentation such as GPS units, and are not much different from their military counterparts. However, unlike military rockets, high-powered model rockets generally do not contain any type of guidance system.

Since the September 11, 2001 attacks, high powered model rocketry in the United States has been even more carefully monitored by the government. Engine vendors and participants must be licensed, and all high-power flights require FAA notification.^{[citations needed]} The September 11, 2001 attacks (often referred to as 9/11—pronounced nine eleven) consisted of a series of coordinated terrorist[1] suicide attacks upon the United States, predominantly targeting civilians, carried out on Tuesday, September 11, 2001. ... The Federal Aviation Administration is the entity of the United States government which regulates and oversees all aspects of civil aviation in the U.S. // Activities Along with the European Joint Aviation Authorities, the FAA is one of the two main agencies worldwide responsible for the certification of new aircraft. ...

Recovery

Model and high-power rockets are designed to be safely recovered and flown repeatedly. The most common recovery methods are parachute and streamer.

Tumble Recovery

The simplest approach, and one only appropriate for small rockets or rockets with a large cross-sectional area, is to have the rocket tumble back to earth. Any rocket which will enter a stable, ballistic trajectory as it falls is not safe to use with tumble recovery.

Parachute/Streamer

The approach used most often in small model rockets, is to use the ejection charge of the motor (see below) to deploy, or push out, the parachute or streamer. Air resistance retards the rocket's fall.

Glide Recovery

In glide recovery, the ejection charge either deploys an airfoil (wing) or separates a glider from the motor. If properly trimmed, the rocket/glider will enter a spiral glide and return safely. In some cases, radio-controlled rocket gliders are flown back to the earth by a pilot in much the way as R/C model airplanes are flown.

Helicopter Recovery

The ejection charge, through one of several methods, deploys helicopter-style blades and the rocket auto-rotates back to earth.

Model Rocket Motors

Most small model rocket motors are single-use engines, with cardboard bodies and lightweight molded ceramic nozzles, ranging in power class from 1/8-A to E. They contain a black powder propellant. Wikipedia does not have an article with this exact name. ... Motors for model rockets and high powered 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. ... Black powder for sporting can be freely bought in Switzerland. ...

Larger rocket motors are also available, using composite propellants made of ammonium perchlorate and a rubbery binder substance contained in a hard plastic case. These motors range in impulse from the B to the O range. Composite motors produce more impulse per unit weight than do black powder motors. Ammonium perchlorate is a chemical compound with the formula NH4ClO4. ... Motors for model rockets and high powered 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. ...

Reloadable motors are also available. These are commercially-produced motors requiring the user to put propellant grains, o-rings and washers (to contain the expanding gases), delay grains and ejection charges into special non-shattering aluminum motor casings with screw-on or snap-in ends (closures). The advantage of a reloadable motor is the cost: because the main casing is reusable, reloads cost significantly less than single-use motors of the same impulse. Reloadable motors are available from D through O class. Motors for model rockets and high powered 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. ...

Motors are electrically ignited with a short length of pyrogen-coated nichrome wire pushed into the nozzle and held in place with flameproof wadding, a plastic plug or masking tape. On top of the propellant is a tracking delay charge which produces smoke but essentially no thrust as the rocket slows down and arcs over. When the delay charge has burned through, it ignites an ejection charge, which is used to deploy the recovery system. Nichrome is a non-magnetic alloy of nickel and chromium. ...

What the Numbers Mean

Rocket motors. From left, 13mm A10-0, 18mm C6-7, 24mm D12-5, 24mm E9-4, 29mm G40-10.

Model rocket motors produced by companies like Estes Industries and Quest Aerospace are stamped with a code (such as A10-3T or B6-4) that tells several things about of motor. Image File history File linksMetadata Download high-resolution version (993x1535, 151 KB)[edit] Summary Photo by Nicholas Cassavaugh (cassavau), taken 7/29/2006. ... Image File history File linksMetadata Download high-resolution version (993x1535, 151 KB)[edit] Summary Photo by Nicholas Cassavaugh (cassavau), taken 7/29/2006. ... Estes Industries is a company based in Penrose, Colorado, USA that designs and builds model rocket and model aircraft engines and kits. ... Quest Aerospace is a company based in Cave Creek, Arizona, USA that designs and builds model rocket motors and kits. ...

Motors are commercially available in many sizes. The Quest Micro Maxx engines are the smallest at a diameter of 6mm. The company Apogee made 10.5mm micro motors, but those were discontinued in 2001. Estes then comes in with "T" (Tiny) motors that are 13 mm in diameter by 45 mm long, while standard A, B and C motors are 18 mm in diameter by 70 mm long. Larger C, D, and E class black powder motors are also available; they are 24 mm in diameter and either 70 (C and D motors) or 95 mm long (E motors). Some motors, such as F and G single-use motors are 29mm in diameter. High-power motors (usually reloadable) are available in 38mm, 54mm, 75mm, and 98mm diameters.

The Letter

The letter at the beginning of the code indicates the motor's total impulse range (commonly measured in newton-seconds). Each letter in successive alphabetical order has up to twice the power of the letter preceding it. This does not mean that a given "C" motor has twice the total impulse of a given "B" motor, only that C motors are in the 5.01-10.0 N-s range while "B" motors are in the 2.51-5.0 N-S range. The designations "1/4 A" and "1/2 A" are also used. For a more complete discussion of the letter codes, see Model rocket motor classification. In classical mechanics, the impulse of a force is the product of the force and the time during which it acts. ... The newton (symbol: N) is the SI unit of force. ... Motors for model rockets and high powered 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. ...

For instance, a B6-4 motor from Estes Corporation has a total impulse rating of 5.0 N-s. A C6-3 motor from Quest Industries has a total impulse of 8.5 N-s. ^[1]

The First Number

The number that comes after the letter indicates the motor's average thrust, measured in newtons. A higher thrust will result in higher liftoff acceleration, and can be used to launch a heavier model. Within the same letter class, a higher average thrust also implies a shorter burn time (e.g., a B4 motor will burn longer than a B6).

The Last Number

The last number is the delay in seconds between the end of the thrust phase and ignition of the ejection charge. Black Powder Motors that end in a zero have no delay or ejection charge. Such motors are typically used as first-stage motors in multi-stage rockets as the lack of delay element and cap permit burning material to move forward and ignite an upper-stage motor.

A "P" indicates that the motor is "plugged". In this case, there is no ejection charge, but a cap is in place. A plugged motor can only be used in rockets which do not need to deploy a standard recovery system such as small rockets which tumble or R/C glider rockets.

Reloadable Motors

Reloadable motor cases. From left: 24/40, 29/40-120, 29/60, 29/100, 29/180, 29/240

Reloadable motors are specified in the same manner as model rocket single-use motors as described above. However, they have an additional designation which specifies both the diameter and length of the motor casing in the form of diameter/length. A reload designed for a 29mm diameter case with a 60mm length carries the designation 29/60 in addition to its impulse specification. Image File history File linksMetadata Download high-resolution version (1282x1579, 170 KB)[edit] Summary Taken by Nicholas Cassavaugh (cassavau) 7/29/2006. ... Image File history File linksMetadata Download high-resolution version (1282x1579, 170 KB)[edit] Summary Taken by Nicholas Cassavaugh (cassavau) 7/29/2006. ...

Safety

Model rocketry is a safe and widespread hobby. Individuals such as G Harry Stine and Vernon Estes helped ensure this by developing and publishing the National Association of Rocketry Model Rocket Safety Code, and by commercially producing safe, professionally-designed and manufactured model rocket motors. Founder and namesake of Estes Industries, the highly-recognized model rocket production company, headquartered in Penrose, CO. ... The National Association of Rocketry (NAR) is the governing body for the sport/hobby of model rocketry in the United States of America. ...

Controversy in the U.S.

Both amateur and model rocketry have come under controversy in the United States following the terrorist attacks on New York and Washington D.C., as federal and state authorities allege that model rockets can be modified to act as weapons.

Authorities argue that all members of the hobby should have to be licensed and their purchases recorded and reported to federal agencies. Critics of such policies, particularly those involved in the hobby itself, argue that while building model rockets capable of going great distances is a relatively simple feat, guidance systems are exceedingly difficult to design and expensive to implement.

The NAR and Tripoli continue to pursue litigation against the BATFE in the matter. NAR can refer to: National Alliance for Reconstruction National Association of Realtors National Association of Rocketry This page concerning a three-letter acronym or abbreviation is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... The Tripoli Rocketry Association is one of the two major organizing body for high power rocketry in the USA (See also: National Association of Rocketry. ... The Bureau of Alcohol, Tobacco, Firearms and Explosives (BATFE or ATFE) is a law enforcement agency within the United States Department of Justice. ...

References:

1. ^ National Association of Rocketry web site: http://nar.org/SandT/NARenglist.shtml

See also

• Hybrid rocket
• Water rocket

A hybrid rocket propulsion system is a rocket engine composed of a solid propellant lining a combustion chamber into which a liquid or gaseous propellant is injected so as to undergo a strong exothermic reaction to produce hot gas that is emitted through a De Laval nozzle for propulsive purposes. ... Water Rocket Launch Water rockets are like their model rocket cousins, except that these are powered by a combination of water and air pressure instead of a chemical propellant. ...

External links

• The National Association of Rocketry (NAR), one of the oldest model rocket clubs in the world
• The Tripoli Rocketry Association
• Canadian Association of Rocketry
• United Kingdom Rocketry Association
• Interessengemeinschaft Modellraketen - IMR (rocketry organization for Germany/Austria/Switzerland)
• Dutch Federation for Rocket Research, the oldest European association
• European Model Rocketry