A telescope is something you look through that magnifies an object by A LOT, usually. The Hubble Space Telescope isn't an ordinary telescope. It is orbiting Earth at around 17,500 mph, or 7823 m/s (meters per second). The Hubble Space Telescope was launched into a low earth orbit on April 24th, 1990 by the NASA Space Shuttle (Atlantis) and has been orbiting alone since. Vehicles use to service this Space Telescope (only the Space Shuttle), but we do not have any vehicles capable of doing so right now.
The Hubble Space Telescope isn't the kind of Telescope that you look through, it contains a computer, takes extremely zoomed in images of stars, exoplants, nebula's, galaxies, black holes, supernovas, and more. It sends these images back to scientists, engineers, and more back here on Earth to observe them and enhance them to make more sense out of them. The Hubble Space Telescope will be replaced with the James Webb Space Telescope in possibly 2021, which will be launched atop an Ariane 5 Rocket, developed by Arianespace.
The Hubble Space Telescope has 6 cameras, and the Telescope costs about $2.5 billion. One of the reasons that the Hubble Telescope is capable of taking such amazing images of other objects millions of light-years away, is because it does not have to deal with Earth's atmosphere. Earth's atmosphere blocks a lot of light from coming into the atmosphere, resulting in a lot of stars' light being weakened, or abolished. This telescope is orbiting about 500km above Earth's surface. The reason we use KM is that it is more modern and most individuals who refer to an orbit measure its apogee and perigee in KM, and its distance from Earth's surface. The Hubble Space Telescope has helped us learn a lot about space, and the James Webb Space Telescope will help us learn even more.