In December of 1609, the remarkable Italian mathematician, craftsman, and astronomer Galileo Galilei turned a telescope of his own design on the night sky and began to make remarkable discoveries. Over the next two months (December and January), he made discoveries that challenged and forever changed mankind's concept and understanding of the universe. With the deployment of the Hubble Space Telescope in 1990, that understanding of the universe took another huge leap forward. The Hubble orbits 600 kilometers (375 miles) above Earth, working around the clock to unlock the secrets of the universe. Using a combination of pointing precision, powerful optics, and state-of-the-art instruments, this massive instrument provides stunning views of the universe that cannot be made using ground-based telescopes or other satellites. Originally designed in the 1970s, the $2.5 billion Hubble Space Telescope was launched in 1990.