Jacob Beser (May 15, 1921 – June 17, 1992) was a lieutenant in the

United States Army Air Forces The United States Army Air Forces (USAAF or AAF) was the major land-based aerial warfare service component of the United States Army and ''de facto'' aerial warfare service branch of the United States during and immediately after World War II ...

who served during

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

. Beser was the radar specialist aboard the ''

Enola Gay The ''Enola Gay'' () is a Boeing B-29 Superfortress bomber, named after Enola Gay Tibbets, the mother of the pilot, Colonel (United States), Colonel Paul Tibbets. On 6 August 1945, during the final stages of World War II, it became the Atomi ...

'' on August 6, 1945, when it dropped the

Little Boy Little Boy was a type of atomic bomb created by the Manhattan Project during World War II. The name is also often used to describe the specific bomb (L-11) used in the bombing of the Japanese city of Hiroshima by the Boeing B-29 Superfortress ...

atomic bomb A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission or atomic bomb) or a combination of fission and fusion reactions (thermonuclear weapon), producing a nuclear expl ...

Hiroshima is the capital of Hiroshima Prefecture in Japan. , the city had an estimated population of 1,199,391. The gross domestic product (GDP) in Greater Hiroshima, Hiroshima Urban Employment Area, was US$61.3 billion as of 2010. Kazumi Matsui has b ...

. Three days later, Beser was a crewmember aboard ''

Bockscar ''Bockscar'', sometimes called ''Bock's Car'', is the United States Army Air Forces Boeing B-29 Superfortress, B-29 bomber that dropped the Fat Man, Fat Man nuclear weapon over the Japanese city of Nagasaki during World War II in the secondand ...

'' when the

Fat Man "Fat Man" (also known as Mark III) was the design of the nuclear weapon the United States used for seven of the first eight nuclear weapons ever detonated in history. It is also the most powerful design to ever be used in warfare. A Fat Man ...

bomb was dropped on

Nagasaki , officially , is the capital and the largest Cities of Japan, city of Nagasaki Prefecture on the island of Kyushu in Japan. Founded by the Portuguese, the port of Portuguese_Nagasaki, Nagasaki became the sole Nanban trade, port used for tr ...

. He was the only person to have served as a strike crew member of both of the 1945 atomic bomb missions.

Background

Jacob Beser grew up in

Baltimore Baltimore is the most populous city in the U.S. state of Maryland. With a population of 585,708 at the 2020 census and estimated at 568,271 in 2024, it is the 30th-most populous U.S. city. The Baltimore metropolitan area is the 20th-large ...

Maryland Maryland ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic region of the United States. It borders the states of Virginia to its south, West Virginia to its west, Pennsylvania to its north, and Delaware to its east ...

. He attended the Baltimore City College (high school) and graduated in June 1938. Beser then studied mechanical engineering at The Johns Hopkins University, also in Baltimore, but dropped out the day after the

attack on Pearl Harbor The attack on Pearl HarborAlso known as the Battle of Pearl Harbor was a surprise military strike by the Empire of Japan on the United States Pacific Fleet at Naval Station Pearl Harbor, its naval base at Pearl Harbor on Oahu, Territory of ...

to enlist in the Army Air Forces. He was Jewish and extremely restless to get into the fight against Hitler. Because of his training and educational background, Beser was sent to Los Alamos and worked on the

Manhattan Project The Manhattan Project was a research and development program undertaken during World War II to produce the first nuclear weapons. It was led by the United States in collaboration with the United Kingdom and Canada. From 1942 to 1946, the ...

in the area of weapons firing and fusing. There, he met or worked with various luminaries such as Robert B. Brode, Norman Ramsey,

Niels Bohr Niels Henrik David Bohr (, ; ; 7 October 1885 – 18 November 1962) was a Danish theoretical physicist who made foundational contributions to understanding atomic structure and old quantum theory, quantum theory, for which he received the No ...

Enrico Fermi Enrico Fermi (; 29 September 1901 – 28 November 1954) was an Italian and naturalized American physicist, renowned for being the creator of the world's first artificial nuclear reactor, the Chicago Pile-1, and a member of the Manhattan Project ...

, Edward Doll, and General

Leslie Groves Leslie Richard Groves Jr. (17 August 1896 – 13 July 1970) was a United States Army Corps of Engineers officer who oversaw the construction of the Pentagon and directed the Manhattan Project, a Classified information#Top_Secret_(TS), top sec ...

Mission

The 509th Composite Group, which Beser served in, was the army unit tasked with deploying the atomic bombs. To practice for the mission, they used practice bombs deemed "

pumpkin A pumpkin is a cultivar, cultivated winter squash in the genus ''Cucurbita''. The term is most commonly applied to round, orange-colored squash varieties, but does not possess a scientific definition. It may be used in reference to many dif ...

s", designed to be similar to the

atomic bomb. The unit began training on December 17, 1944, at the Wendover Army Air Field in Utah, before being deployed to the island of

Tinian Tinian () is one of the three principal islands of the Commonwealth of the Northern Mariana Islands (CNMI). Together with uninhabited neighboring Aguiguan, it forms Tinian Municipality, one of the four constituent municipalities of the Northern ...

in May 1945. The unit's First Ordnance Squadron was responsible for handling the bombs. On August 6, 1945, the first atomic bomb to be used in combat was dropped by a

B-29 Superfortress The Boeing B-29 Superfortress is a retired American four-engined Propeller (aeronautics), propeller-driven heavy bomber, designed by Boeing and flown primarily by the United States during World War II and the Korean War. Named in allusion to ...

bomber A bomber is a military combat aircraft that utilizes air-to-ground weaponry to drop bombs, launch aerial torpedo, torpedoes, or deploy air-launched cruise missiles. There are two major classifications of bomber: strategic and tactical. Strateg ...

, the ''

'', over the Japanese city of

, killing 70,000 people, including 20,000 Japanese

combatant Combatant is the legal status of a person entitled to directly participate in hostilities during an armed conflict, and may be intentionally targeted by an adverse party for their participation in the armed conflict. Combatants are not afforded i ...

s and 20,000 Korean slave laborers. The thirteen-hour mission to Hiroshima under the command of pilot Colonel Paul Tibbets, began at 0245

time. By the time the ''Enola Gay'' rendezvoused with its two accompanying B-29 Superfortresses at 0607 over

Iwo Jima is one of the Japanese Volcano Islands, which lie south of the Bonin Islands and together with them make up the Ogasawara Subprefecture, Ogasawara Archipelago. Together with the Izu Islands, they make up Japan's Nanpō Islands. Although sout ...

, the group was three hours from the target area. "Little Boy's" detonation was triggered by radar sensors on the bomb that measured its altitude as it fell. Beser's job was to monitor those sensors and ensure that there was no interference that could have detonated it prematurely. The bomb fell away from the aircraft at 09:15:17

time. Beser did not watch the bomb detonate but he heard the bomb's radar signals switch on and then cut off at the moment the intense light generated by its detonation filled the plane. Three days later in a second B-29 Superfortress bomber, ''

'', Beser repeated this task over

with

, the

plutonium Plutonium is a chemical element; it has symbol Pu and atomic number 94. It is a silvery-gray actinide metal that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exhibits six allotropes and four ...

implosion bomb that became the second and last atomic bomb used in combat. Beser was the only crew member to accompany both atomic bomb missions and besides the commanding officers/pilots, had a scientific understanding of the new weapons' potential and destructiveness, as a result of his earlier high school and university education.

Later life

In 1946, Beser was one of the founding members of

Sandia National Laboratories Sandia National Laboratories (SNL), also known as Sandia, is one of three research and development laboratories of the United States Department of Energy's National Nuclear Security Administration (NNSA). Headquartered in Kirtland Air Force B ...

, in

New Mexico New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...

. He came home to Baltimore and in the mid-1950s began a long career working on defense projects for Westinghouse. When asked about his atomic bomb missions on numerous interviews, Beser made the following response: He wrote a book about the experiences of flying on both flights; ''Hiroshima & Nagasaki Revisited'' was written in 1988. Beser was an amateur ("ham") radio operator, holding the callsign W3NOD. He was inducted into the "Hall of Fame" of his alma mater high school, Baltimore City College, the third oldest public high school in America.

Military decorations

His decorations include:

Silver Star citation

:Beser, Jacob :First Lieutenant, U.S Army Air Forces :393d Bombardment Squadron, 509th Composite Group, 20th Air Force :Date of Action: August 6, 1945 :Headquarters, 20th Air Force, General Orders No. 69 (September 22, 1945) :Citation:

Notes

External links

Audio Recording of 1985 Lecture by Jacob Beser
Voices of the Manhattan Project * * {{DEFAULTSORT:Besser, Jacob 1921 births 1992 deaths Jewish American military personnel Military personnel from Baltimore United States Army Air Forces personnel of World War II Manhattan Project people Baltimore City College alumni Johns Hopkins University alumni United States Army Air Forces officers Recipients of the Air Medal Recipients of the Silver Star Recipients of the Distinguished Flying Cross (United States) People from Pikesville, Maryland 20th-century American Jews