Photo

The 42-foot portable radio telescope (right) working next to the permanent 40-foot telescope at Green Bank, West Virginia. From 1967 through 1976, the 42-foot served as the fourth, remote member of the Green Bank Interferometer (GBI), the test array for the Very Large Array (VLA). The 42-foot’s trailer carried the dish as stacked panels and included a built-in, donut-shaped drive and a small control room.

The 40-foot telescope in Green Bank, West Virginia is a lightweight, transit telescope. In 1962, it became the world’s first full-automated radio telescope. From 1961 until 1967, the 40-foot merrily went along observing a small catalog of radio sources whose brightness change over time. The data it collected traveled from the telescope’s prime focus receiver through a cable (at left) and into a control building. In 1987, it was re-purposed as an educational telescope.

A nearly face-on view of the 40-foot radio telescope in Green Bank, the world’s first automated radio telescope. Its surface is a fine mesh, because it does not need to be as accurate as other radio telescopes that observe higher frequencies. Visiting students use this telescope for astronomical observing projects each year.

The 45-foot portable radio telescope replaced the less accurate 42-foot as the fourth element in the Green Bank Interferometer in 1973. After 15 years working dozens of miles from Green Bank, it was permanently relocated at the Observatory. In this photo, it has just arrived at its new home and is still using its portable control room — the trailer at right.