Propellants

In a liquid rocket, the propellants, the fuel and the oxidizer, are stored separately as liquids and are pumped into the combustion chamber of the nozzle where burning occurs.

In a solid rocket, the propellants are mixed together and packed into a solid cylinder. Under normal temperature conditions, the propellants do not burn; but they will burn when exposed to a source of heat provided by an igniter. Once the burning starts, it proceeds until all the propellant is exhausted.

You can stop the thrust of a liquid rocket by turning off the flow of propellants.

Chemical propulsion uses a fuel and an oxidizer, converting energy stored in the chemical bonds of the propellants, to produce a short, powerful thrust.

Chemical propulsion uses a fuel and an oxidizer, converting energy stored in the chemical bonds of the propellants, to produce a short, powerful thrust, or what we see as fire.

This scientific assessment monitors the progress of the Montreal Protocol, a global agreement reached in 1987 and put into place in 1989, intended to protect the Earth’s ozone layer by phasing out the chemicals that deplete it, often used as propellants in household products or in air conditioning.