The original control room for the 140-foot telescope sits at the base of the telescope, inside a concrete building with walls that are 3-feet thick. The guidance and data systems lined the wall of this room on the ground floor. Three to four people would be in this room during early observations with the 140-foot telescope in the 1960s and 1970s, including operators, engineers, and astronomers. Now, the updated and renamed 43-meter telescope can be run by a laptop in a drawer!
Coming Down to Earth
When the 200-foot tall dish telescope in Green Bank, West Virginia needed receiver maintenance, operators drove its 140-foot (43-meter) dish to within four feet of the ground. An engineering tower was winched up until the apex of the telescope was nestled inside. Then, in a protected space, the sensitive equipment was removed, replaced, and finely adjusted. These days, the 140-foot has not been using a receiver at its apex. Instead, a sophisticated second reflector sits here to bounce waves to receivers nestled in the hole in the center of the dish. The tower is still used to work on the apex.
Waiting for Liftoff
The 266-ton dish superstructure (BUS) for the 140-foot (43-meter) telescope in Green Bank, West Virginia has been completely assembled and awaits hauling onto the telescope’s yoke in November, 1964. The maneuver took longer than expected: the superstructure was dropped accidentally during a derrick failure.
Polishing the Bearing
This 17.5-foot hemispherical bearing 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 was then finished and polished by Westinghouse. Nearly 17 tons of metal were ground off during this process of getting the surface smooth with no bump more than .003 inches. The bearing still weighs in excess of 150 tons– one of the largest steel castings ever poured, certainly the largest ever cast of 3.5% nickel.
Inside the Bearing Room
The giant, shiny metal ball is the 17.5-foot hemispherical heart of the 140-foot telescope in Green Bank, West Virginia. It supports the telescope’s full rotating weight of 2700 tons on a .005-inch thick oil film (see pumps in foreground) between it and the main hydrostatic pad supports (black). The bearing is bolted to the end of the polar shaft. The shaft slowly spins against the turning of the Earth to allow the 43-meter dish telescope to keep itself aimed on a particular object in space.
Honeycomb Hemisphere
This honeycomb of metal was to be the support structure for a 22-foot across welded steel sphere bearing for the 140-foot (43-meter) telescope in Green Bank, West Virginia. However, the welds created more than 70 small cracks in the metal, a condition known as “brittle fracture.” The cold Green Bank winters would have spelled doom for this bearing, and resulted in the loss of the entire telescope. This design was abandoned in 1962 for a smaller cast bearing.