Other
Model Rocketry
Aerial photography
Cameras and video cameras can be launched on model rockets
to take photographs in-flight. Model rockets equipped with the Astrocam, Snapshot
film camera or the Oracle digital camera, or with homebuilt equivalents, can
be used to take aerial photographs.
These aerial photographs can be taken in many ways. Mechanised
timers can be used or passive methods may be employed, such as strings that
are pulled by flaps that respond to wind resistance. Microprocessor controllers
can also be used. However, the rocket's speed and motion can lead to blurry
photographs, and quickly changing lighting conditions as the rocket points
from ground to sky can have an impact on video quality. Video frames can also
be stitched together to create panoramas. As parachute systems can be prone
to failure or malfunction, model rocket cameras need to be protected from
impact with the ground.
Instrumentation and experimentation
Model rockets with electronic altimeters can report
and or record electronic data such as maximum speed, acceleration, and altitude.
Rocket modelers often experiment with rocket sizes, shapes,
payloads, multistage rockets, and recovery methods. Some rocketeers build
scale models of larger rockets, space launchers, or missiles.
Some high altitude rockets deploy a smaller 'second stage
rocket' during flight. Once the main rocket engine begins to die out, a second
stage is fired from the main. This greatly increases altitude as the speed
of the second rocket adds to the speed of the first rocket. For example if
a rocket is traveling at 150mph then the second stage deploys at an additional
60mph from the main, the second stage is now at 210mph. However, this is not
perfect as other variables such as weather may influence the flight
High Power Rocketry
As with low power model rockets, high power rockets
are also constructed from lightweight materials. Unlike model rockets, high
power rockets often require stronger materials such as fiberglass, composite
materials, and aluminum to withstand the higher stresses during flights which
often exceed Mach 1 (~700 mph) and over 10,000 ft altitude.
High power rockets are propelled by larger motors ranging
from class H to class O. 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.
The Bureau of Alcohol, Tobacco and Firearms (BATF) has
classified Ammonium Perchlorate Composite Propellant (APCP), the most commonly
used propellant in high power rocket motors as explosives. Therefore, at this
time, to store and possess most high-power rocket motors in the US requires
a permit from the BATF. The national rocketry organizations, Tripoli Rocketry
Association and National Association of Rocketry (NAR), have sued the BATF
to have APCP removed from the explosives lists. Among other things, Tripoli
and NAR contend that APCP is slow burning and does not function by explosion
and is therefore not subject to BATF regulation, and that the BATF added APCP
to the explosives list without following the agency's own rules.
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 NAR Model Rocket Safety Codes and by commercially producing
safe, professionally-designed and manufactured model rocket motors.
One of the main motivations for the development of the
hobby in the 1950s and 1960s was to provide young people the opportunity to
construct flying rocket models without having to engage in dangerous construction
of motor units and direct handling of explosive propellants.
Flammable items such as fuels, rocket
engines and similar items cannot be shipped via Canada Post and as such
The
Quality Hobby Shop
does not carry them.
From Wikipedia, the free encyclopedia.
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