The document discusses the Hubble Space Telescope (HST). It provides background on the telescope, including its purpose of allowing astronomers to make high-resolution observations from outside the Earth's atmosphere. Details are given on the telescope's specifications, costly $4.5-6 billion price tag, 1990 launch by the Space Shuttle Discovery, and its mission to observe planets, stars, and galaxies across ultraviolet and infrared spectrums. The document also describes initial issues with the primary mirror being the wrong shape that required correctors, and HST's contributions like more accurate distance measurements of stars and verification of the universe's expansion.