Carved in the hilly terrain, a thousand feet wide and 167 feet deep, Arecibo has been listening to radio waves arriving from the cosmos since 1963, and today it remains the world’s largest and most sensitive radio telescope. It is also one of the most recognizable, appearing as a backdrop in the movies “Contact” and “GoldenEye.”

Image An image of the near-Earth asteroid 1999 KW4 produced by the telescopes radar systems. Credit... Steven J. Ostro/J.P.L. and Daniel J. Scheeres/University of Michigan

In an era of tight and tightening budgets, a review panel for the foundation’s astronomy division two years ago looked for places where money could be freed up for new facilities. It recommended a 25 percent cut in Arecibo’s foundation financing by 2011 and then another 50 percent cut, to $4 million, in 2011.

The panel said Arecibo should look to other institutions and agencies to make up for the 2011 cut; if it could not find the money, the panel said, the foundation should consider closing it.

A quarter of its staff was laid off last year. The telescope is now on hiatus for repainting, but when it resumes operation, the number of observing hours will be cut, and nearly half of its receivers will be furloughed. Its emphasis will shift to large, continuing surveys, and smaller projects like Dr. Lovell’s may be much more squeezed than in the past.

An outcry followed the review panel’s decision, particularly from planetary scientists who thought that the group had overlooked Arecibo’s role in cataloging potential dangers from asteroids. Its radar can precisely plot the orbit of an asteroid to determine if it could be on course for a collision with Earth.