the series consisted of four tower shots, two at 200 feet and two at 300 feet
(7: 1):
Event
DOG
EASY
GEORGE
ITEM
Date
Type
Yield
(kilotons)
8 April
Tower
NA*
21 April
Tower
47
9 May
Tower
NA
25 May
Tower
NA
*Not announced
4.5.1
Background and Objectives of Operation GREENHOUSE.
The purpose of the four GREENHOUSE tests was to continue development of
nuclear weapons for defense.
More specifically, work was proceeding at this
time on developing thermonuclear weapons, and the GREENHOUSE tests were part
of this process (7: 1).
In 1949, the Soviet Union detonated its first atomic bomb, providing the
impetus for the United States to proceed with development of a bomb whose
energy would come from the fusion, or joining, of light elements.
weapon is also called a thermonuclear, or hydrogen, bomb.
Such a
The Atomic Energy
Commission received Presidential approval for work in this area in January
1950 after lengthy debate in high defense circles over the feasibility and
advisability of such weapons (7: 21).
Although the GREENHOUSE nuclear devices were not thermonuclear devices,
two of them involved thermonuclear experiments, and one test, GEORGE, was an
important step toward thermonuclear devices.
GEORGE demonstrated the
initiation of a sustained thermonuclear reaction by use of a fission reaction.
This led directly to the first successful thermonuclear test, MIKE (Operation
IVY), some 16 months later.
In addition, ITEM, the fourth test of the series,
involved boosting the efficiency of fission explosions.
Development of this
experiment had been planned before the Soviet test in 1949 (7: 21).
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