It was mistakenly ground to the wrong shape due to the use of a miscalibrated testing device .
The flawed primary mirror of the Hubble Space Telescope was ground and polished in Danbury by Perkin - Elmer 's Danbury Optical System unit from 1979 to 1981 .
Danbury was mistakenly ground to the wrong shape due to the use of a miscalibrated testing device .
The flawed primary mirror of the Hubble Space Telescope was ground and polished in Danbury by Perkin - Elmer 's Danbury Optical System unit from 1979 to 1981 .