After more than five years at the helm, Robert L. Brown will step down as director of the National Astronomy and Ionosphere Center (NAIC) at Cornell, which manages the Arecibo Observatory in Puerto Rico.

Brown's resignation is effective May 31, but he will remain on the NAIC staff as director emeritus and special adviser to the director until Aug. 31, to complete several new collaborations with the European, Chinese and Argentinean research communities in support of the Arecibo Observatory mission.

The 1,000-foot-diameter (305 meters) Arecibo telescope was completed in 1963 to provide access to state-of-the-art observing for scientists in radio astronomy, solar system radar and atmospheric studies. NAIC manages the facility under a contract with the National Science Foundation (NSF).

As NAIC director, Brown led the center through the successful Cornell bid for the cooperative agreement with the NSF and managed several scientific innovations, including the commissioning of the Arecibo L-band Feed Array (ALFA), which surveys the sky quickly to discover new pulsars and galaxies.

After NSF's Senior Review of Astronomical Facilities recommended sharp cuts in Arecibo's budget, he has been able to demonstrate that the observatory will continue to do excellent science despite the severe constraints imposed by decreased NSF funding, said Joseph Burns, the I.P. Church Professor of Theoretical and Applied Mechanics and Astronomy and vice provost for physical sciences and engineering at Cornell.

"On behalf of the entire Cornell, NAIC and Arecibo Observatory communities, we thank Bob for his great efforts and commitment to the future of the Arecibo Observatory, and we wish him all the best in his retirement," said Burns.

Brown received his B.A. from the University of California-Berkeley in 1965, and his M.S. and his Ph.D. from the University of California-San Diego, both in 1969. all in physics. Before coming to NAIC in 2003, he was deputy director of the National Radio Astronomy Observatory, headquartered in Charlottesville, Va., where he served in various capacities for 18 years.

Robert Burhman, senior vice provost for research, is forming a committee to be chaired by John Silcox, the David E. Burr Professor of Engineering and former vice provost for physical sciences, to seek a successor. The committee will include representatives from the Arecibo Observatory staff, the NAIC advisory bodies and the national community of Arecibo users.