Model Rocketry and Siege Engine Glossary Letter L


Model Rocketry and Siege Engine Glossary Letter L

Glossary
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L1, L2, L3
Levels one through three: reference to the three levels of high power rocketry certification
There are four levels in The Canadian Association of Rocketry
Laminar Flow
A smooth flow of air, noted for lack of turbulence. In current theory , it is modeled as consisting of layers of air having similar speed and density
Laminated Wood
Wood made from of multiple layers, commercially made plywood being the most common example
Land Shark
The condition in which a rocket, for whatever reason, fails to attain air flight and slides along the ground under power
Launcher
A device which supports and positions a rocket to permit movement in a desired direction during takeoff
Launch Controller
An electrical device used to activate the motor igniter, which in turn ignites the motor. The launch controller should always incorporate a lock-out device such as a key, to prevent accidentally activating the igniter before the rocket is ready to be launched
Launch Happy
Euphoria from being overly addicted to burnt fuel fumes on a particular day. Symptoms include repeatedly launching a model on increasingly more powerful motors until there are no motors left or the rocket shreds
Launch Lug
Usually, a tube attached to the side of the rocket to accommodate a launch rod, to stabilize the rocket while building up air speed
Launch Pad
An assembly containing the launch rod or tower and blast deflector if any, which permits the rocket to remain steady until launched
Launch Rail
A stiff rail, often with a cross section in the shape of a square letter C or I. Lugs on the rocket ride on the rail. Using a rail rather than a rod provides the advantage that a rail can be made much stiffer than a rod, providing better wind resistance and preventing vibration-induced whipping of the launch rod
Launch Rod
A stiff rod, whose diameter can be from 1/8" to 1" depending on the size and weight of the rocket, along which a rocket flies for the first few feet of its travel. The launch rod stabilizes the rocket’s flight while it builds up air speed
Launch Tower
A launch pad containing any sort of stabilizing device other than a launch rod. In model rocketry, a tower commonly consists of 3 or 4 smooth rods which support the rocket on all sides, eliminating the need for a launch lug
Lawn Dart
Similar to a Core Sample but requires the nosecone to remain in place prior to impact. Named after a lawn game of the sixties in which large darts were thrown into the air to land inside rings placed on the ground about 25' apart (as in horse shoes)
LBP
Live Biological Payload. Transport of any vertebrate animal is currently in violation of all rocketry safety codes
LCO
Launch Control Officer. Person in charge of controlling the range and launching rockets
LDRS
Large and Dangerous Rocket Ships: the name of the annual TRA launch
Leading Edge
The front edge of a wing or fin
LEUP
BATF Low Explosive User Permit for rocket motors with greater than 62.5 grams of propellant, as well as other substances deemed by the government to be low explosives such as Thermalite
Lift
The aerodynamic force on a body measured perpendicular to the direction of motion. Lift is used to turn, stabilize, or support a rocket depending on the location, shape and angle of a surface with respect to the rocket body
Liftoff Mass
See GLOW
Lite-ply
A model builders plywood, noted for its low density
  • A rocket propellant that consists either of a mixture of two or more liquids (a fuel , oxidizer, and sometimes an additive) or of a liquid chemical compound that provides its own fuel and oxidizer
  • Also any one of the liquid ingredients that are to go into the mixture, i.e., the fuel, the oxidizer, or the additive, separately
LMR
Large Model Rocket: a term sometimes used synonymously with Mid-Power Rocket
Low Power
Typically rockets flying on motors in the A to D range
LOX
Liquid Oxygen
LPR
Low Power Rocket: a term sometimes used synonymously with Model Rocket
Lucerne Soft Landing
A condition - experienced only on ground surfaces of cracked playa clay - in which a rocket which has landed remains in a semi-upright position with one fin stuck in a crack in the ground.


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