Fire extinguisher useful in fighting fires with a particular group of fuel. Specifications for fire extinguishers are set out in the standard AS/NZS 1841, the most recent version being released in 2007. All fire extinguishers must be painted signal red. Except for water extinguishers, each extinguisher has a coloured band near the top, covering at least 10% of the extinguisher's body length, specifying its contents. In Australia, yellow (Halon) fire extinguishers are illegal to own or use on a fire, unless an essential use exemption has been granted, this is due to the ozone-depleting nature of halon. According to the standard BS
Cold gas thruster gas thrusters are mostly useful for vernier engines, and are employed chiefly for simplicity and reliability. Cold gas thruster A cold gas thruster is a propulsive device that uses pressurized inert gas as the reaction mass. The compressed gas is released through a propelling nozzle to generate a cold jet thrust. A cold gas thruster usually consists of simply a pressurized tank containing gas, a valve to control its release and a propelling nozzle, and plumbing connecting them. A very simple example would be the use of a handheld or nitrogen gas fire extinguisher while sitting down in a rolling