Page "Primary mirror" Paragraph 5

The largest optical telescope in the world as of 2009 to use a non-segmented single-mirror as its primary mirror is the 8. 2 m ( 8. 7 yards ) Subaru telescope of the National Astronomical Observatory of Japan, located in Mauna Kea Observatory on Hawaii since 1997 ; however, this is not the largest diameter single mirror in a telescope, the U. S ./ German / Italian Large Binocular Telescope has two 8. 4 m ( 9. 2 yards ) mirrors ( which can be used together for interferometric mode ).

Both of these are smaller than the 10 m segmented primary mirrors on the two Keck telescope.

Radio and submillimeter telescopes use much larger dishes or antennae, which do not have to be made as precisely as the mirrors used in optical telescopes.

The Hubble Space Telescope has a 2. 4 m ( 7 ft 10 in ) primary mirror. The correctly ground backup primary mirror built by Eastman Kodak for the Hubble space telescope ( the mirror was never coated with a reflective surface, hence its Honeycomb mirror | honeycomb support structure can be seen ).

It now resides in the National Air and Space Museum in Washington, DC.