Los Alamos National Labs with logo 2021

Manhattan Project legend turns 100

John Tucker celebrates a century.
October 1, 2018
Black and white photo of a man's shoulders and head; he is in a Navy uniform.

As a Naval officer during World War II, John Tucker served at Los Alamos and in the Pacific Islands as a member of Project Alberta, arming and readying the world’s first atomic weapons for use against Japan.


“You really put the icing on my 100th birthday cake.”- John Tucker

By Sierra Sweeney

Wearing a suit and a bolo tie, John L. Tucker blew out the candles on his detonator-shaped cake. “You really put the icing on my 100th birthday cake,” Tucker said to his audience at the May 8 private celebration in Los Alamos.

The crowd included members of the Detonator Science and Technology group and other Laboratory leadership who reflected on Tucker’s 40-plus years of service to the national defense mission and his contributions to detonator science, which continue to support the safety and performance of the United States’ nuclear weapons stockpile.

“Since the Manhattan Project, Tucker has made numerous contributions to the Weapons Programs, and his legacy continues to carry the day with two major references he authored,” said event organizer Daniel Preston, referring to the Los Alamos Detonator Catalog and Los Alamos Detonator History, both of which are still in use today. “Our work today parallels those who came before us, and learning about the contributions of one of the founding fathers of detonator science is inspiring and motivating.”

Recognized as a key member of the Manhattan Project, Tucker’s contributions to detonator science are virtually unparalleled. As a Naval officer during World War II, he served in Los Alamos and in the Pacific Islands as a member of Project Alberta, which ensured an atomic bomb could be successfully dropped by aircraft. For his part, Tucker designed bomb-handling equipment and wrote disassembly, inspection, testing and assembly check sheets. He personally selected the fireset that armed Fat Man, the bomb used over Nagasaki on August 9, 1945.

After the war, Tucker returned to Los Alamos to lead the development of the Laboratory’s Detonator Firing site, now known as TA-40. He spent the remainder of his career at the Lab, officially retiring in 1982 but staying active as a consultant for another decade. 


Portrait photos of two elderly men.

Bob Cowan and Krik Krikorian.

In memoriam

Robert “Bob” Cowan passed away on July 25, 2018, at the age of 98. Cowan began his career at Los Alamos in 1951 and was a staff member for more than 30 years and then a Senior Laboratory Fellow. Cowan was awarded the Los Alamos Medal in 2008 and was internationally recognized as the “father of atomic structure calculations.” He wrote one of the world’s first general atomic structure computer codes that was used to understand and diagnose atomic spectra. Today, his codes and algorithms are still used extensively at the Laboratory and throughout the world.

One of the last living scientists involved in the Manhattan Project, Nerses “Krik” Krikorian, passed away on April 18, 2018, at the age of 97 at his home in Los Alamos. Krikorian began his career as a uranium chemist at Union Carbide in New York. After the war he made his way to Los Alamos, where he worked first as a scientist and then as an intelligence analyst until his retirement in 1991. He became a Laboratory Fellow in 1985 and was awarded the Los Alamos National Laboratory Medal in 2003.