Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Private spaceflight is flight above 100 km Earth altitude conducted by and paid for by an entity other than a government. In the early decades of the Space Age, the government space agencies of the Soviet Union and United States pioneered space technology augmented by collaboration with affiliated design bureaus in the USSR and private companies in the US. Later on, large defense contractors began to develop and operate space launch systems, derived from government rockets and commercial satellites. Private spaceflight in Earth orbit includes communications satellites, satellite television, satellite radio, astronaut transport and sub-orbital and orbital space tourism. Learn more about current and future developments of private space flight in this book.