A system that provides control of location and attitude of spacecraft by using rocket engines to generate motion. Spacecraft propulsion systems come in various forms depending on the specific mission requirements. Each exhibits considerable variation in such parameters as thrust, specific impulse, propellant mass and type, pressurization schemes, cost, and materials. All of these variables must be considered in deciding which propulsion system is best suited to a given mission. Typical spacecraft applications include communications satellites, science and technology spacecraft, and Earth-monitoring missions such as weather satellites. Orbital environments range from low-Earth to geosynchronous to interplanetary.