Motors will drive the 15 million pound structure with the precision of a fine watch. As it tracks a celestial object, every part of the telescope will maintain its position to a fraction of an inch, from the 16 four-foot driving wheels to the topmost arm 475 feet (145 meters) above the ground. The 210-foot (64 meter) diameter circular track the telescope rotates on is flat to a ten thousandth of an inch (.00254 mm), allowing the telescope to be positioned to an accuracy of 7 arcseconds. This stability is possible because the track will rest on a foundation of 135,000 cubic feet (3823 cubic meters) of high-strength concrete that extends down to bedrock.
The reflector surface will consist of 2000 aluminum panels, each 50 square feet, that are smooth to a few thousandths of an inch and are adjusted continually, using a unique laser-ranging system, to compensate for gravitational sag and other forces on the telescope. The 100,000 square foot (9290 square meters) surface will reflect radio waves from distant galaxies to sensitive state-of-the-art receivers located more than 400 feet (122 meters) above the ground in a receiver room that is reached by taking two 20-story elevators.
The telescope will be operated as a national facility by the NRAO, and it is expected to make major advances in our understanding of pulsars, quasars, interstellar chemistry, the evolution of stars, and the structure of the Universe