problems.
Simultaneously the Korean War had made the Enewetak proving
grounds rather vulunerable in addition to being very expensive in tems
of military resources.
Two days after he declared the national emer-
gency, President Truman approved the Commission's recommendation to
establish a continental proving ground at the Las Vegas bombing and
gunnery range in Nevada.
One of the chief advantages of the Las Vegas
site was that using it posed fewer radiological hazards to Americans
than any of the other sites considered.
Due to the Korean emergency the
Commission began planning its first continental test series on December
20, 1950, and conducted the first test explosion a little over a month
later.
The test series, called operation Ranger, eventually consisted
of six test shots, all of them of relatively small yields, and provided
important data for fission weapons and for the thermonuclear program
tests scheduled for the Pacific in April.?*
Quickening the Pace of Testing
Meanwhile, the hycrogen banb program was floundering. Calculations
by Los Alamos mathematician Stanislaw Ulam demonstrated that a proposed
design for the hydrogen barb would not ignite a fusion reaction.
A few
weeks later Ulam suggested a new approach and by April Edward Teller had
grasped
the
key
to
starting
the
fusion
reaction.
A
successful
experiment in the spring test series confirmed that Teller was on the
right track. 15
The spring test series,
called Greenhouse, was conducted in the
Pacific in April and May 1951.
principles for fission weapons,
‘The series was designed to test design
and because of Teller's recent idea,
|
would be an important milestone in the development of thermonuclear