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 program from the two destroyed orbiters. The Space Shuttle program was extended several times beyond its originally envisioned 15-year life span because of the delays in building the United States space station in low Earth orbit—a project which eventually evolved into the International Space Station. It was formally scheduled for mandatory retirement in 2010 in accord with the directives President George W. Bush issued on January 14, 2004 in his Vision for Space Exploration. A$2.5 billion spending provision allowing NASA to fly the Space Shuttle beyond its then-scheduled retirement in 2010 passed the Congress in April 2009, although neither NASA nor