Stephen H. Maslen, a retired aeronautical engineer who was an expert in fluid dynamics, died Tuesday at the Broadmead retirement community in Cockeysville of heart failure. He was 89.
The son of Harold Carpandale Maslen, a civil engineer, and Ethel Canavan Maslen, a homemaker, Stephen Harold Maslen was born in Cleveland and moved with his family to Mount Kisco, N.Y., where he graduated from Mount Kisco High School.
He earned a bachelor's degree in 1945 and a master's degree in 1947 in aeronautical engineering from Rensselaer Polytechnic Institute in Troy, N.Y. In 1952, he earned his doctorate in applied mathematics from Brown University.
Dr. Maslen began his career in 1947 with the old National Advisory Committee for Aeronautics in Cleveland, which after its dissolution was merged in 1958 into the newly established National Aeronautics and Space Administration.
In 1960, he moved to Baltimore when he went to work for Martin Marietta Corp. and later was assistant director of the company's Research Institute for Advanced Studies.
Dr. Maslen's major professional work involved re-entry of space capsules for the Gemini mission and fluid dynamics for the Apollo mission.
Dr. Maslen, who lived in Towson, retired in 1988.
He was a member of the National Academy of Engineering and a fellow of the American Institute of Aeronautics and Astronautics.
In 1951, he married the former Virginia Lee Howeth, who died in 1970.
In 1983, he married the former Andree Stern and together the couple enjoyed hiking, camping, canoeing and participating in archaeological digs. They were also world travelers.
"He considered himself a humanist and maintained an interest in world events and humanitarian causes," said his daughter, Catherine Maslen of Baltimore.
Dr. Maslen was a member of the Towson Unitarian Universalist Church, 1710 Dulaney Valley Road, where a memorial service will be held at 3 p.m. April 19.
In addition to his wife and daughter, Dr. Maslen is survived by a son, Eric Maslen of Harrisonburg, Va.; a stepson, Peter Stern of Baltimore; a stepdaughter, Erika Stern of Duxbury, Mass.; seven grandchildren; and a great-granddaughter. Another son, Stephen R. Maslen, died in 2014.