Cold gas thruster
Encyclopedia
A cold gas thruster is a rocket engine/thruster that uses a (typically inert) gas as the reaction mass.
A cold gas thruster usually simply consists of a pressurized tank containing gas, a valve to control its release and a nozzle, and plumbing connecting them. A very simple example would be the use of a handheld CO2 or nitrogen gas fire extinguisher
while sitting down in a rolling office chair
; motion is achieved by pointing the nozzle in the direction opposite of the desired movement and activating the extinguisher.
Because the gas is usually unheated, speed at the throat is low and very low performance is achieved; in a vacuum with nitrogen gas a specific impulse
of 68 seconds can be achieved.
Cold gas thrusters are mostly useful for vernier engines, and are employed chiefly for simplicity and reliability.
A cold gas thruster usually simply consists of a pressurized tank containing gas, a valve to control its release and a nozzle, and plumbing connecting them. A very simple example would be the use of a handheld CO2 or nitrogen gas fire extinguisher
Fire extinguisher
A fire extinguisher or extinguisher, flame entinguisher is an active fire protection device used to extinguish or control small fires, often in emergency situations...
while sitting down in a rolling office chair
Office chair
An office chair, or desk chair, is a type of chair that is designed for use at a desk in an office. It should be comfortable and adjustable and can swivel 360 degrees.-History:...
; motion is achieved by pointing the nozzle in the direction opposite of the desired movement and activating the extinguisher.
Because the gas is usually unheated, speed at the throat is low and very low performance is achieved; in a vacuum with nitrogen gas a specific impulse
Specific impulse
Specific impulse is a way to describe the efficiency of rocket and jet engines. It represents the derivative of the impulse with respect to amount of propellant used, i.e., the thrust divided by the amount of propellant used per unit time. If the "amount" of propellant is given in terms of mass ,...
of 68 seconds can be achieved.
Cold gas thrusters are mostly useful for vernier engines, and are employed chiefly for simplicity and reliability.
See also
- Rocket engineRocket engineA rocket engine, or simply "rocket", is a jet engineRocket Propulsion Elements; 7th edition- chapter 1 that uses only propellant mass for forming its high speed propulsive jet. Rocket engines are reaction engines and obtain thrust in accordance with Newton's third law...
- monopropellant rocketMonopropellant rocketA monopropellant rocket is a rocket that uses a single chemical as its propellant.-Chemical-reaction monopropellant rockets:...
- QuadQuad (rocket)In rocketry, the Armadillo aerospace Quad vehicle is a computer controlled VTVL rocket that is used to compete in the Lunar Lander Challenge.-General description:...
- used cold gas thrusters