Joseph P. Young, 81, an aerospace engineer who retired from the NASA’s Goddard Space Flight Center in 1991, died Sept. 28 at his home in Laurel.

He suffered a traumatic brain injury in a bicycle accident in September 2011 and never fully recovered, his daughter Cynthia Shelberg said.

Mr. Young began his NASA career in 1963. As a senior spacecraft systems engineer, he participated in many of the agency’s space-flight programs. After leaving NASA, he worked 20 years in Beltsville for Swales Aerospace, which in 2007 was acquired by Alliant Techsystems. His specialties included technology related to earth-observing satellites.

Joseph Perry Young was born in Refugio, Tex. He was a 1951 graduate of the University of Oklahoma and in 1954 received a master’s degree in aerospace engineering from the University of Southern California. In 1960, he received a master’s degree in mechanical engineering from Drexel University in Philadelphia. He served in the Army from 1955 to 1957.

Before joining NASA, Mr. Young worked for Rockwell International in California and for Martin Marietta Corp. in Baltimore.

Mr. Young was an enthusiastic bicyclist and participated in long-distance and mountain rides throughout the United States.

He was a member of Oaklands United Presbyterian Church in Laurel.

Survivors include his wife of 55 years, Lucille Gillan Young of Laurel; four daughters, Cynthia Shelberg of Ashburn, Carol Halligan of Timonium, Md., Mary Jo Naber of Nashua, N.H., and Claudia Florenzo of Ellicott City; and nine grandchildren.

— Bart Barnes