Assertion: telescope's mirror | /r/HasProperty | ground to wrong shape
Facets:
value: owing to faulty testing procedures
type: CAUSE
Source sentences:
text: About one month after launch, it became apparent that the HST’s large primary mirror had been ground to the wrong shape owing to faulty testing procedures by the mirror’s manufacturer.
text: The New Technology Telescope initially had the same problem as the Hubble Space Telescope - the mirror was ground to the wrong shape due to a mis-calibrated null corrector.