| scheduled shots do not give the necessary data to meet the
early capability POLARIS requirement.
4,
It has been necessary also to add to the program one
other laboratory test.
It was previously believed that the
data required for the design of one warhead for the NIKE
HERCULES could be obtained from the test of a basically similar
device already included in the program.
However,
it is now
felt necessary to test this second device in order to obtain
the required data.
5. One other test of the original program has been deferred
to the underground test series of very low-yield devices
planned for the fall 1958 at the Nevada Test Site which I
described in my November 23 letter,
and which will be conducted
as a separate test series to be known as Operation MILLRACE,
6,
In summary,
the over-all change to the HARDTACK program
has been an increase of two scheduled shots, making a total of
19 scheduled laboratory and 5 scheduled DOD effects shots.
In
addition, there will be three contingent shots whose firing
depends on the outcome of other shots in the series.
Attached
to this letter is a summarization of the scheduled and contingent
nuclear shots. in the HARDTACK and MILLRACE programs and their
objectives,
7.
In addition to these nuclear firings, we must fire some
two to ten safety tests of certain designs to establish that,
detonated accidentally,
no nuclear reaction would occur.
if
These
safety tests will be conducted at the Nevada Test Site, three
in the spring 1958 and seven in the fall 1958.
Earliest firing
of two of the three is necessitated by the expedited POLARIS
program,
-~ 18 -
Appendix "c"