Space telescope Hubble Space Telescope, which was launched on April 24, 1990 by the Space Shuttle "Discovery" (STS-31). Performing astronomy from ground-based observatories on Earth is limited by the filtering and distortion of electromagnetic radiation (scintillation or twinkling) due to the atmosphere. Some terrestrial telescopes can reduce atmospheric effects with adaptive optics. A telescope orbiting Earth outside the atmosphere is subject neither to twinkling nor to light pollution from artificial light sources on Earth. As a result, the angular resolution of space telescopes is often much smaller than a ground-based telescope with a similar aperture. Space-based astronomy is even more important for
Space Shuttle Atlantis with Space Shuttle "Atlantis" over the course of its 33 missions. Because the shuttle sometimes flew crew members arriving and departing Mir and the ISS, not all of them launched and landed on "Atlantis". Astronaut Clayton Anderson, ESA astronaut Leopold Eyharts and Russian cosmonauts Nikolai Budarin and Anatoly Solovyev only launched on "Atlantis". Similarly, astronauts Daniel Tani and Sunita Williams, as well as cosmonauts Vladimir Dezhurov and Gennady Strekalov only landed with "Atlantis". Only 146 men and women both launched and landed aboard "Atlantis". Some of those people flew with "Atlantis" more than once. Taking them into account, 203 total