Operation HARDTACK I consisted of 35 nuclear
tests conducted at the Pacific Proving Ground between April 28
and August 18, 1958. These tests included balloon, surface,
barge, underwater, and rocket-borne high-altitude tests. The
first test, Yucca, was a nuclear device attached to a helium
balloon launched from the USS Boxer near Enewetak Atoll.
HARDTACK I consisted of three portions; the first was the
development of nuclear weapons. This was a continuation of the
type of testing conducted at Enewetak and Bikini during the
early and mid-1950s. In these tests, the weapons development
laboratories, Los Alamos Scientific Laboratory and the
University of California Radiation Laboratory (later named
Lawrence-Livermore National Laboratory), detonated their
experimental devices, while the Department of Defense (DoD)
provided support and conducted experiments that did not
interfere with Atomic Energy Commission activities.
The second portion, sponsored by the DoD,
consisted of the underwater tests Wahoo and Umbrella. Wahoo was
detonated in the deep, open ocean southwest of Boken Island, and
Umbrella inside the western end of the lagoon at Enewetak. The
purpose of these tests was to improve the understanding of the
effects of underwater explosions on Navy ships and material.
These were continuations of earlier underwater testing that
included Baker in CROSSROADS at Bikini in 1946 and WIGWAM off
the U.S. West Coast in 1955.
The DoD also sponsored the third portion,
addressing the military problems of air-borne nuclear weapon
defense. Three high-altitude tests featured rocket-borne Teak
and Orange at Johnston Island and balloon-hoisted Yucca between
Enewetak and Bikini.
