The Salyut program (Russian: Салют; lit. Salute or Fireworks) was the first space station program unertaken by the Soviet Union, which consisted of a series of nine single-module space stations launched over a period of eleven years from 1971 to 1982. Intended as a project to carry out long-term research into the problems of living in space and a variety of astronomical, biological and Earth-resources experiments, the program allowed space station technology to evolve from the engineering development stage to long-term research outposts in space. Ultimately, experience gained from the Salyut stations went on to pave the way for multimodular space stations such as Mir and the International Space Station, with each of those stations possessing a Salyut-derived core module at its heart.