H.R. (Buzz) Brockett, 55, a senior associate of the Systematics general Corp. in Falls Church and a former official of the National Aeronautics and Space Administration, died Wednesday at Holy Cross Hospital in Silver Spring. He had cancer.

Mr. Brockett was born in Atlanta, Neb. He served in the Army in World War II and then attended the University of West Virginia. He graduated from Lafayette College in Easton, Pa.

He began his career in the government space program at the Langley Research Center in Hampton, Va., which then was operated by the National Advisory Committee for Aeronautics, a predecessor of NASA. Mr. Brockett helped develop a number of tests for wind tunnels and related matters.

In 1959 he was transfered to NASA headquarters in Washington and worked on projects for tracking rockets in Project Mercury, the nation's first manned space program. From 1968 until his retirement in 1975, Mr. Brockett was deputy associate administrator in the NASA office of tracking and data acquisition.

He joined Systematics General the year he left the government. There he conducted studies on the allocation of radio frequencies for national and international telecommunications systems.

Mr. Brockett held Nasa's Exceptional Service Award.

Survivors include his wife, Ann, of Bethesda, where the family lives; two sons, Lee, of Germantown, Md., and Steve, of Bethesda, a daughter. Connie of Richmond, and his mother, Maude Brockett of Holdrege, Neb.