The Hubble Space Telescope primary maairror is being polished with a person overlooking it.

Hubble Space Telescope Primary Mirror

This photograph shows the Hubble Space Telescope's primary mirror being polished at the Perkin-Elmer Corporation's large optics fabrication facility. After the 8-foot-diameter mirror was ground to shape and polished, the glass surface was coated with a reflective layer of aluminum and a protective layer of magnesium fluoride, 0.1- and 0.025-micrometers thick, respectively. The purpose of Hubble, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of Earth's atmosphere. The Marshall Space Flight Center had responsibility for design, development, and construction of the observatory, and the Perkin-Elmer Corporation in Danbury, Connecticut, developed the optical system and guidance sensors. Date Created: 1981-01-01

Credits: NASA