The Spartan spacecraft were a series of experiments carried by the Space Shuttle. They addressed a variety of scientific questions, and capitalized on the Space Shuttle's ability to accommodate long duration experiments that are large or heavy, or that require retrieval or other on-orbit operations. The Spartan program was based on the idea of a simple, low-cost platform deployed from a space shuttle in orbit for a 2-3 day flight, then recovered and returned to Earth. The platform freed experiments of any shuttle pointing constraints.