History of the telescope a wider field of view than a classic Cassegrain. During the period 1850–1900, reflectors suffered from problems with speculum metal mirrors, and a considerable number of "Great Refractors" were built from 60 cm to 1 metre aperture, culminating in the Yerkes Observatory refractor in 1897; however, starting from the early 1900s a series of ever-larger reflectors with glass mirrors were built, including the Mount Wilson 60-inch (1.5 metre), the 100-inch (2.5 metre) Hooker Telescope (1917) and the 200-inch (5 metre) Hale telescope (1948); essentially all major research telescopes since 1900 have been reflectors. A number of 4-metre class (160 inch)
James Webb Space Telescope timeline James Webb Space Telescope timeline This page lists selected events from the chronology of the James Webb Space Telescope, a planned international 21st century space observatory. It is intended to be a premier observatory of the 2020s, combining the largest mirror yet on a near-infrared space telescope with a suite of technologically advanced instruments from around the world. JWST is expected to cost at least 8.8 billion dollars, including design, construction, and 5 years of operations (does not include extended mission funding) or International contributions. Its likely peak year for funding was probably 2014, when the project ate up more