Photo – Page 88 – National Radio Astronomy Observatory

Still Working After All These Years

The 140-foot telescope in Green Bank, West Virginia was completed in 1965 and has been a very busy instrument ever since. It discovered several organic molecules in space, tracked satellites whizzing overhead, and studied pulsars among many other projects. Currently, renamed the 43-meter, it is a ground station for the world’s only orbiting radio telescope, Spektr-R.

Maintenance tower for the 140-foot telescope

A Mouthful

The 140-foot telescope in Green Bank gets an upgrade as its prime focus is swallowed by the receiver tower. Inside the tower, an engineer is installing fiber optic control devices that allows the small reflecting mirror in the cage to be adjusted very precisely. This helps it to better aim its focused radio waves onto the receivers nestled in the middle of the 43-meter dish.

Late Afternoon at the 140-foot

Looking south at the 140-foot (43-meter) telescope on a gorgeous summer afternoon in Green Bank, West Virginia.

Portrait of a New Telescope

When the 140-foot (43-meter) telescope was completed in Green Bank, West Virginia in 1965, it was the epitome of engineering innovation. It stands 200 feet tall and weighs 8200 tons. To this day, no other polar-aligned telescope of its huge size exists anywhere else in the world.

The ball bearing for the 140-foot telescope

Gem in the Rough

This 17.5-foot hemispherical piece is the structural heart of the 140-foot (43-meter) telescope in Green Bank, West Virginia. It supports the full rotating weight of 2700 tons on the .005-inch thick oil film between it and the main hydrostatic pad supports. Cast by General Steel Industries, it weighs in excess of 150 tons– one of the largest steel castings ever poured, certainly the largest ever cast of 3.5% nickel. Its size was limited by the small country railways and tunnels between its casting site in Eddystone, Pennsylvania and the Green Bank site.

Mimicking the Earth’s Axis

The 140-foot telescope in Green Bank, West Virginia is the largest equatorially-mounted telescope in the world. That means that it moves on a gear parallel to the equator of the Earth because it spins on an axis aligned to that of the Earth. In this photo, its two axes of motion are in view. One is the giant white semi-circular tube with just-visible toothy gears around its edge. This gear is driven by the polar shaft which is aligned to the axis of the Earth (the white shaft braced at the right end of the deck and aiming up at an angle pointing to about 10 o’clock). When the Earth turns, this axis turns in the opposite way, to keep the 43-meter dish aimed on the sky. The tilting gear is the wedge shape under the dish’s support structure.

The National Radio Astronomy Observatory is a facility of the U.S. National Science Foundation operated under cooperative agreement by Associated Universities, Inc.
	Founded in 1956, the NRAO provides state-of-the-art radio telescope facilities for use by the international scientific community. NRAO telescopes are open to all astronomers regardless of institutional or national affiliation. Observing time on NRAO telescopes is available on a competitive basis to qualified scientists after evaluation of research proposals on the basis of scientific merit, the capability of the instruments to do the work, and the availability of the telescope during the requested time. NRAO also provides both formal and informal programs in education and public outreach for teachers, students, the general public, and the media.
	The U.S. National Science Foundation (NSF) is an independent federal agency created by Congress in 1950 "to promote the progress of science; to advance the national health, prosperity, and welfare; to secure the national defense..."
	AUI collaborates with the scientific community and research sponsors to plan, build, and operate cutting-edge facilities. We cultivate excellence, deliver value, enhance education, and engage the public.