Polishing the mirror of the Hubble Telescope, 1980s.

Polishing the mirror of the Hubble Telescope, 1980s. The Hubble Space Telescope (HST), was designed to see seven times further into space than had been possible before, without the distortion caused by the earth's atmosphere. HST is a reflecting telescope and its main mirror has a diameter of 2 1/2 meter. Work began in 1977 and HST was finally launched by Space Shuttle Discovery on 24 April 1990. Problems with its giant mirror meant that it did not initially work as well as expected. Corrective optics were installed in 1993, greatly improving the telescope's performance, enabling it to view the Universe in unprecedented detail. (Photo by Oxford Science Archive/Print Collector/Getty Images)