Harold has responded (Tab A) to your questions of last week regarding the
study of ground mobile basing systems for an M–X missile.2 In reading the memo
you might note the following points:
First, the road mobile system that the study team seems to favor carries
an “M–X” missile that is about the size
of the Minuteman III missile. While its more energetic fuel allows it to
throw more RVs over
[Page 565]
a longer range than Minuteman III, it has
about half the throw weight of the larger M–X variants that the Air Force wants. (S)
Tab A
Memorandum From Secretary of Defense Brown to President
Carter3
Washington,
April 7,
1979
SUBJECT
(U) You asked for a status report on
Ground Mobile M–X. We have had a
team restudying this problem the past few months in parallel with
our study of Air Mobile M–X. Both
studies were under the direction of the Under Secretary of Defense
for Research and Engineering. The Ground Mobile team consisted of
senior personnel from the Air Force Office of System Analysis and
two contractors (Boeing and Martin). All of them have had extensive
experience in missiles and their basing systems (the Air Force team
leader was the same officer who led our design team on GLCM basing). Their study is
essentially finished and will be ready for review, along with the
Air Mobile report, in a week or two.
(U) The study has considered two
different types of ground mobile systems—road mobile and off-road
mobile. Preliminary findings on each of these follow:
Road Mobile:
(S) The missile would be carried on a
Transporter Erector Launcher (TEL)
which would weigh (including the missile) about 200,000 pounds
(limited by the load-carrying capability of the interstate system).
[3 lines not declassified]
[Page 566]
(S) The system would be based in the
southern part of the U.S. where weather problems would be minimal.
Each of the bases would have security appropriate for the protection
of nuclear weapons on day-to-day alert. The TELs would be kept in the open at known locations to
facilitate verification. On the receipt of strategic warning, the
TELs would go out on public
roads at maximum speed until they were so widely dispersed that they
could not be successfully barraged.
(S) The baseline system would have 250
TELs and missiles and 1250
warheads. We estimate the acquisition cost at about $16B (in FY 78 dollars) which is about $5B less
than MPS. Annual O&S costs
would be about $0.5B, about $0.1B more than MPS.
For a postulated attack of 70% of the Soviet ICBM
RVs (the same threat we used for
MPS and Air Mobile
calculation),
- a)
- None of the systems survive a surprise attack, even with a
full 30 minutes of tactical warning;
- b)
- With 1 hour of “strategic” warning, none survive;
- c)
- 50% of the systems survive an attack for which we have 4
hours of strategic warning;
- d)
- 80% of the systems (1000 RVs) survive an attack for which we have 6
hours of strategic warning.
(S) To achieve a degree of
survivability against a surprise attack it is necessary to maintain
some percentage of the systems dispersed on the highways. The
difficulty with peacetime dispersal is the public interface problems
created by moving nuclear missiles about on public highways and the
possibility of an accident. We will continue to examine the legal
and environmental aspects of such a peacetime dispersal.
Off-Road Mobile:
(S) In the off-road mobile concept,
the missile achieves its survivability by being moved about on its
TEL at frequent intervals. To
avoid public interface problems, its movement during peacetime is
limited to Defense Department bases in the southwest (Yuma Bomber
Range, Nellis Air Base, e.g.). Because of the possibility of
barraging this limited area, the TEL would have to be very hard [less
than 1 line not declassified] and therefore very heavy (on
the order of 1,000,000 pounds), and expensive. If confined to DOD land, such a system would be able
to provide the equivalent of 1,000 to 2,000 independent aim-points
for Soviet 1 MT warheads.
(U) Further consideration and detail
will be included in my presentation of ICBM rebasing options to you following a PRC on the subject later this
month.
