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
Laser propulsion laser electric propulsion, using magnetohydrodynamics to convert laser energy to electricity and to electrically accelerate air around a vehicle for thrust. Laser propulsion Laser propulsion is a form of beam-powered propulsion where the energy source is a remote (usually ground-based) laser system and separate from the reaction mass. This form of propulsion differs from a conventional chemical rocket where both energy and reaction mass come from the solid or liquid propellants carried on board the vehicle. The basic concepts underlying a photon-propelled "sail" propulsion system were developed by Eugene Sanger and the Hungarian physicist György Marx. Propulsion concepts using laser-energized