Enhancing the VLA

The Very Large Array in Socorro, New Mexico, “produces more refereed papers per year than any telescope at any wavelength on the surface of the planet—only the Hubble Space Telescope beats it,” says Paul Vanden Bout, director of the VLA’s parent organization, the National Radio Astronomy Observatory (NRAO). To keep it at the leading edge, the radio array will be upgraded to increase its sensitivity roughly 10-fold and extend its bandwidth to cover the full range from 1 to 50 GHz.

Modernization of the 22-year-old VLA will begin this year. The 27 dishes, each 25 meters in diameter and weighing 230 tons, will be sequentially refitted with new electronics and optical fibers, and the array will get a new correlator. The expanded VLA, or EVLA, is slated to be completed by the end of the decade. Longer-range—and not yet funded—plans include adding new dishes to increase the resolution.

NSF will pay $58.3 million toward the EVLA, NRAO is putting in $11 million, Mexico is contributing $2 million in components, and Canada is building the $11 million correlator. The VLA cost $78.6 million in 1972 dollars (an estimated $300 million today) so the upgrade, says Vanden Bout, gives you “10 VLAs for $150 million bucks. It’s a bargain.”