Space-based observatories
The space-based observatories consist of telescopes and their instruments (cameras, spectrographs, etc) that are flying in orbit around the Earth. The main advantage of the space telescopes is their placement above the Earth’s atmosphere, which rids them of the influence of the atmospheric turbulence. Because of that, their spatial resolution and image quality is much better than that of ground-based telescopes. The most famous of the space telescopes is the Hubble Space Telescope (HST).
Another important advantage of the space telescopes is that they can observe in parts of the electromagnetic spectrum that are inaccessible from the ground. The Earth’s atmosphere is opaque the UV, X-ray and gamma-ray emission, as well as for part of the infrared emission. These domains are observable only from space. The most productive X-ray space observatories are NASA’s Chandra telescope and the European Space Agency’s (ESA) XMM Newton telescope.