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Harold J. Hasenfus, 93, Manhattan Project Veteran and Technical Director of NAVSPASUR at Dahlgren

Obituary and service information from Covenant Funeral Service.

Harold J. Hasenfus, 93, Manhattan Project Veteran and Technical Director of NAVSPASUR at Dahlgren

Harold J. Hasenfus, an accomplished engineer, scientist and mathematician as well as beloved husband, father and grandfather died of pneumonia on Thursday, June 12, 2014, at Johns Hopkins Hospital in Baltimore, Md., surrounded by three of his four children. He was 93.

Mr. Hasenfus, a longtime resident of Fredericksburg, headed the Naval Space Surveillance System in Dahlgren for 26 years and was a Manhattan Project veteran.  During his life, he witnessed the arrival of atomic energy, rockets, digital computers and earth satellites, spending his professional career of 42 years working in each of these new fields in turn as they emerged.

Harold Joseph Hasenfus was born in 1921 in New York City.  He graduated from John Adams High School in Queens.  He attended the City College of the City of New York, where he was a varsity wrestler and a member of the engineering fraternity Sigma Kappa Tau.  He graduated from CCNY with a degree in mechanical engineering in June 1943, at which time he joined the Army and attended Officer Candidate School.

While on active duty during World War II, Mr. Hasenfus worked at two of the Manhattan Project’s locations, the University of Chicago and Oak Ridge, Tenn. In Chicago, he helped to solve operational problems associated with the chemical separation of plutonium from other fission products. At Oak Ridge, he worked seven days a week as a project engineer at the newly constructed S-50 thermal diffusion plant separating the fissile U-235 isotope from uranium hexafluoride.   A video of Mr. Hasenfus commenting on his work on the Manhattan Project can be found by searching YouTube for “Harold Hasenfus” and “Manhattan Project.”

Following the war, Mr. Hasenfus worked as an ordnance engineer, becoming Chief of the newly formed Rocket Branch of the Army’s Ballistics Research Laboratory, located at Maryland’s Aberdeen Proving Ground.  Mr. Hasenfus left active duty in 1948, but remained an officer in the Army Reserve, eventually retiring as a Lieutenant Colonel.

During his time at the Rocket Branch, Mr. Hasenfus oversaw significant advances in artillery rocket ballistics, creating performance improvements that are taken for granted today.  Due to the complexities of these problems, the Rocket Branch had available to it ENIAC, the world’s first electronic digital computer, and its successors, EDVAC and ORDVAC.

In 1961, Mr. Hasenfus became the first Technical Director of the U.S. Naval Space Surveillance System (NAVSPASUR), created to enable detection of all satellites overflying U.S. territory.  He remained in that position until retiring in 1986, at which time the title of Technical Director Emeritus was conferred upon him.


He was academically active all his life, being elected to Pi Mu Epsilon and earning Master’s degrees in Electrical Engineering, Physics and Mathematics, the latest of those being conferred on him in 1985, at the age of 64.  He was also physically active, remaining a runner into his early 60s.

Mr. Hasenfus was also very active in his community and in social activities.  He was a singer, lector and cantor for the Catholic Church for most of his life.  He served as Cub Scout Leader for many years. Later, he was a member of the Fredericksburg Singers, accompanying them on singing tours of both England and France.   He belonged to many social clubs along with his wife, including the Parnassus Book Club.   He was interested in very many subjects, including genealogy, the sciences, mathematics, history and languages such as French, German, Latin and Greek.

After his retirement he added the role of accomplished stage actor, appearing in several plays at the Riverside Center Dinner Theater and other local venues.  Harold enjoyed spending time with people.   He was a very good man, well liked and much respected by all who knew him.  Former Secretary of State James R. Schlesinger once characterized Mr. Hasenfus as “an exceptional and accomplished man of many achievements.”

Mr. Hasenfus frequently let it be known that of all of his achievements, the one of which he was most proud was his four children. He is survived by those children, Jim of Barrington, R.I.; Steve of Alexandria;  Jean Marie of Fredericksburg; and Edward of Pasadena, Md.; by his sister, Dorothy Tenore of Dennisport, Mass., and his brother, Roger Hazen of Dongola, Ill.; and by two granddaughters, Angelica and Abigail Hasenfus of Barrington.  He was predeceased by his wife of 50 years, Mary Margaret Boone Hasenfus.

The family will receive friends from 6 to 9 p.m. Wednesday, June 18, and Thursday, June 19, at Covenant Funeral Service, Fredericksburg. A rosary service will be held from 6 to 6:30 p.m. Thursday, June 19, at the funeral home.

A Mass of Celebration will be held at 10 a.m. Friday, June 20, at St. Mary Catholic Church, Fredericksburg.

Mr. Hasenfus will be interred with his wife in Arlington National Cemetery at a later date.  Burial arrangements are incomplete at this time.

The family asks that memorial gifts be made to the American Cancer Society, South Atlantic Division Inc., 4240 Park Place Court, Glen Allen, Va. 23060–9904.

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