Hale Telescope mirror.. It was completed in 1948 and is still in active use. The Hale Telescope represented the technological limit in building large optical telescopes for over 30 years. It was the largest telescope in the world until the Russian BTA-6 was built in 1976, and the second largest until the construction of the Keck Observatory Keck 1 in 1993. Hale supervised the building of the telescopes at the Mount Wilson Observatory with grants from the Carnegie Institution of Washington: the telescope in 1908 and the telescope in 1917. These telescopes were very successful, leading to the rapid advance in understanding
Lovell Telescope up by a household radio, the Lovell Telescope was the only telescope capable of tracking Sputnik's booster rocket by radar; it first located it just before midnight on 12 October 1957. It also located Sputnik 2's carrier rocket at just after midnight on 16 November 1957. The telescope also took part in some of the early work on satellite communication. In February and March 1963, the telescope transmitted signals via the moon and Echo II, a NASA balloon satellite at 750 km (466 mi) altitude, to the Zimenki Observatory in the USSR. Some signals were also relayed from the USA