Hubble Null Corrector caused first image quite embarrassing
NASA has revealed how a mirror aboard its $1.5 billion Hubble Telescope became the wrong shape. Perkin-Elmer, which manufactured the Hubble telescope's optics, completed the 2.4-meter primary mirror incorrectly because of errors in a test instrument, NASA said last week.
Null Corrector Science
Hubble Problem detection of null corrector
NASA found that a lens used in the test instrument, called the 'reflective null corrector, is about a millimeter out of place. According to preliminary analysis, an error of this magnitude might be responsible for Hubble spherical aberration.
An astronomer at Beloit College in Wisconsin, and a codesigner of Hubble, Daniel Schroeder, says that the crucial error, the misalignment of a lens by a millimeter, is 'huge' by optical standard...