Name of Iran their country "Arya", "Iran", "Iranshahr", "Iranzamin" (Land of Iran), "Aryānām" (the equivalent of "Iran" in the proto-Iranian language) or its equivalents. The term "Arya" has been used by the Iranian people, as well as by the rulers and emperors of Iran, from the time of the Avesta. Evidently from the time of the Sassanids (226–651 CE) Iranians have called it "Iran", meaning "the land of Aryans" and "Iranshahr". In Middle Persian sources, the name "Arya" and "Iran" is used for the pre-Sassanid Iranian empires as well as the Sassanid empire. As an example, the use of the name "Iran" for
In-space propulsion technologies mission- enabling breakthroughs that will revolutionize space exploration. There is no single propulsion technology that will benefit all missions or mission types. The requirements for in-space propulsion vary widely due according to their intended application. The described technologies should support everything from small satellites and robotic deep space exploration to space stations and human missions to Mars applications. The technology areas are divided into four basic groups: (1) Chemical propulsion, (2) Nonchemical propulsion, (3) Advanced propulsion technologies, and (4) Supporting technologies; based on the physics of the propulsion system and how it derives thrust as well as its technical maturity.