||To wear away under stresses of heat, oxidation, and high velocity gas
||Increasing velocity with time.
||Propellant ingredient used to enhance physical or ballistic properties.
||Tail end of vehicle.
||Sturdy structure meant to stop or deflect high velocity objects created
in a test stand explosion.
||Tubular grain uninhibited on the ends which can provide a nearly neutral
burning characteristic (BAtch TESt motor).
||The rubbery fuel used in solid propellants - also in Hybrid fuels.
||Strong construction used to house personnel and instruments in a static
or flight test. Generally has extremely durable overhead construction.
||Pressurizing gas flowing through a fixed orifice with no other regulation
to expel liquid propellants.
|Boiler Plate Motor
||A very solid overdesigned thrust chamber used to test new propellants
or new injector concepts.
||A ring of bolts used to hold a closure in place.
||A wall between two areas - in rocketry usually between two tanks, instrumentation
sections or between motor chamber and tank.
||Less sophisticated observation area than a blockhouse. Generally has
overhead protection to qualify as a bunker.
||The actively burning surface of a rocket grain, either solid or hybrid.
||In solids, the rate at which the burning surface recedes as it combusts.
Affected by pressure, temperature and the scrubbing of hot gases.
||A thin (metal) disc which fails at a known pressure, releasing pressurant,
fuel or oxidizer into flow lines.
||In instrumentation, the shielded electrical lines which conduct signals
from the transducers to the instrumentation recorders, amplifiers, DAS,
etc. The shields are tied to one grounding point.
||A propellant grain cast directly into a chamber and made to bond securely
to the chamber wall.
||Generally a tubular section of a rocket motor (solid, liquid, or hybrid)
in which combustion takes place.
||The pressure generated within a motor by the combustion of the rocket
||Any mechanical part which seals a port or chamber.
||A low frequency instability in rocket motors in periods of up to several
seconds - dangerous in that it can project a vehicle off a launcher and
then it becomes an erratic projectile.
||Low frequency instability in a liquid motor.
||The cavity within a solid or hybrid grain - often shaped to offer higher
burning surface or a constant surface with regression.
||Temperature at which gases liquefy at atmospheric pressure.
||Data Acquisition System
||Specific weight per volume unit.
||Downrating of the area of an orifice or nozzle due to flow separation
||An electric igniter similar to a model rocket igniter.
||A "cigarette burning" grain inhibited or case bonded on the external
surface burning only on its face.
||Increased burning rate in solids and hybrids created by the action
of high velocity gases.
||Largest section of a divergent cone on the exhaust section of a rocket
||Applies to the exit or expansion section of a rocket nozzle.
||The ratio of the area of the exit diameter of the exhaust portion of
a nozzle to the area of the throat - determines Cf (thrust coefficient).
||Spring steel leaf used in supporting test stand table at four corners.
||Used in test stands to feed propellants to liquid or hybrid motors
without imposing major loads on test structure; also used in some gimballed
motors to permit swiveling motion.
||Towards the nose of the rocket.
||Component(s) of the propellant which are Oxidized or burned.
||Used in attitude controlled vehicles to support motor so it can be
deflected to produce control vectored thrust. Also the support of a gyroscope
in a stable platform or in a rate gyro.
||Any size of monolithic propellant structure designed to be combusted
as rocket propellant.
||The divergence of the exhaust cone referring to the angle one side
makes with the centerline. Conventionally 15 to 18 degrees but may be larger
||A mechanical clamp for securing a motor to a test stand or to secure
an entire vehicle to a launch pad and may be remotely released.
||The circumferential loading of a cylindrical mechanical body. Mustbe
kept well below the yield strength of the material.
||Refers to the use of mixed states of matter in a bi-propellant system
- solid-liquid, gas-solid, etc. Either oxidizer or fuel may be the liquid
or gas component.
||Important operation used to determine the suitability of a vessel or
motor chamber for pressure containment. Done with water-filled units taken
to high pressures with small hand piston pumps (system is aerated prior
to test) under appropriate safety conditions.
||Propellants which ignite on contact.
||Shift in calibration of transducer when on "return" from actuation
||Bonding non-propellant material to restrict the burning surface of
a propellant grain.
||Used to produce flame, hot particles, and gas pressure to ignite a
rocket motor. See electric match.
||A system of orifices used to direct propellant to create mixing and
fog production for combustion.
||Thermal protection used in motors to prevent heat transfer to temperature
||An insulated sleeve made from phenolic, EPDM, fiberglass, impregnated
cardboard, or any number of materials which protects the combustion chamber
while the motor is burning.
||Refers to liquid propellant in rocket terminology.
||Transducer which measures force as a function of resistance or voltage.
||Pressure curve which is nearly constant with time.
||An alloy of nickel and chromium drawn into a wire of varying gauges
typically used to heat a pyrogen to ignition with the application of sufficient
voltage and amperage.
||The portion of the rocket motor which accelerates the gases to sonic
velocity at the narrowest part of the nozzle (the throat) then expands
them to greater velocity in the exit cone. In experimental rocketry
this is generally turned on a lathe from graphite and /or phenolic.
||The component of a propellant which provides the combustion supporting
element (generally Oxygen, but can be Fluorine, Chlorine, Sulfur, etc.)
||Another term for core.
||Refers to tubing and hoses used as conduits for propellants and pressurants
in a liquid or hybrid propulsion system.
||The cross section of a core, perforation or port - used in Hybrid tocalculate
G (Mass Flux Rate).
||Measure of unit of force per unit area exerted by combustion products
during rocket motor operation, or in a propellant or pressurant tank.
||A threaded orifice which can be fitted with a pressure gauge or pressure
transducer for determining the pressures within a motor while in operation.
||Outputs electrical signal proportional to pressure.
||Pressure time curve which shows increased pressure with duration.
||Refers to a mixture of oxidizer and fuel or to either oxidizer or fuel
used in rocket motors.
||Any device which creates a semi-permanent display of data, generally
on magnetic tape, chart paper, oscilloscope screen, digital display, etc.
||Pressure vs Time curve in which the pressure decreases with duration.
||Inhibiting a grain.
||Device which provides propulsion through the expulsion of some mediumat
||High frequency instability of liquid motors, generally destructive.
||Remnant of propellant or fuel in solid or hybrid motors as a consequence
of initial geometry.
||Fuel and/or oxidizer in a condensed, solid state of matter.
||The force per unit mass per unit time generated by a rocket propellant
under fixed conditions of pressure, temperature, and mixture ratio.
||Firing a rocket motor in a restrained, protected area for purposes
of recording chamber pressure, thrust, wall temperature, plume characteristics,
burning duration, etc.
||A strand burner measures the burn rate of an energetic composition
in an elevated pressure environment. Also called a Crawford Bomb.
||Refers to gradual reduction in pressure and thrust at end of burning
of a rocket motor.
||Vessel which contains oxidizer, fuel or pressurant for a rocket motor.
||Referring to either threading of a hole or to the port in a chamber
designed to take pressure measurements.
||Designed to restrain a motor during test and permit enough motion to
actuate a load cell - see static test.
||Force produced by a rocket motor by the efflux of matter at high velocity.
||The product of specific impulse and weight of propellant, the product
of thrust and duration.
||Outputs electrical signal proportional to a force or pressure input.
||Unfilled volume of a propellant tank and rarely the unfilled volume
in a solid motor.
||Refers to a free-standing grain which burns on all surfaces. This method
leaves the chamber wall unprotected by propellant and is therefore seldom
||Is equal to 1/2 the difference between the inside diameter and outside
diameter of a chamber or tank. The actual gauge of the material used to
make the vessel.