Orion most commonly refers to: Orion , a hunter in Greek mythology Orion , a constellationOrion may also refer to: Astronomy and space Orion Arm, a spiral arm in the Milky Way galaxy Orion Nebula, a nebula also known as M42 Orion , an American sounding rocket Orion 1 and Orion 2 Space Observatories, Soviet space observatories onboard space station Salyut 1 (1971) and Soyuz 13 (1973), respectively Orion , an Argentine