As we all know, the HubbleTelescope has a built-in vision problem: The primary mirror has a "spherical aberration" -- its shape isn't quite right.

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[From EndToEndPrinciple (violated, in this case)]

"The HubbleTelescope didn't need to be tested end-to-end; the components had been proven correct."  ;->

	 :	"The military units were optically tested after assembly. The HST was not tested in this way, a "saving" that permitted Perkin-Elmer to submit the low bid for the mirror contract. Such a test would have unambiguously revealed a spherical aberration of the magnitude present in the HST." -- from "Mega-Projects & -Problems; The Hubble in Trouble" at http://www.npl.washington.edu/AV/altvw44.html

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It appears that of the three types of UnitTest''''''s that were applied to the main mirror, one showed OK, but the two others indicated a spherical aberration.  The passing test was trusted, and the failing tests ignored.

See "Why the Hubble Space Telescope Went Wrong?" at http://www.uoguelph.ca/~ebaig/brian.html

"Scientist says errors discounted in making of Hubble" at http://www.chron.com/content/interactive/space/missions/sts-103/hubble/archive/900916.html

	 :	"Eastman Kodak, another bidder for the mirror contract, lost in the competition but was subcontracted by Perkin-Elmer to construct a backup mirror. Astronomers, if they had been in charge of the HST project, would certainly have compared the two mirrors and selected the one of best optical quality for the telescope (and in the process, discovered the aberration problem).  [...]" -- from "Mega-Projects & -Problems; The Hubble in Trouble" at http://www.npl.washington.edu/AV/altvw44.html

"Not Listening Leads to Cloudy Vision for Hubble Telescope" at http://www.optimo-inc.com/InfoRoomScopeIssuesFBI.html

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"NASA Fact Sheet," "Hubble Space Telescope's First 125 Days" published by the NASA Marshall Space Flight Center, Huntsville, Alabama, September 1990 -- http://www.jsc.nasa.gov/er/seh/hubble.html

"Overcoming Hubble's Troubles" at http://www.ex.ac.uk/nlo/news/nlonews/1994-01/9401-12.htm