Air-breathing engines

Air-breathing engines use atmospheric air to oxidise the fuel carried, rather than carrying an oxidiser, as in a rocket. Theoretically, this should result in a better specific impulse than for rocket engines.

Air-breathing engines include:

* Internal combustion engine
* Jet engine
* Ramjet
* Scramjet
* Pulse detonation engine
* Pulse jet
* Liquid air cycle engine/SABRE