Attached is a report prepared by the Office of Science and Technology
Policy Space Advisory Group on the anti-satellite issue. Their
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recommendations are that the
US acquire an electronic as well as
a non-nuclear interference capability. In light of current discussions,
you will likely find the report of interest. This group also has
completed its review on space based radars that you requested.2 I will forward this report to
you separately.
Attachment
Memorandum From the Chair of the Advisory Group on
Space Systems (Buchsbaum) to the Special Advisor to the
President for Science and Technology (Press)4
Washington, August 26, 1977
SUBJECT
-
US Anti-Satellite
Capability
The growing Soviet use of satellites for military functions has
heightened the need to revise US
policy with respect to a US
anti-satellite capability. The Group believes that the Soviets
should not be allowed a one-sided sanctuary in space for critical
space systems that directly support their military forces. [4 lines not declassified] These systems would
be appropriate targets for attack under some conditions. The number
and types of such space systems are expected to grow.
The Group believes it is undesirable for the US to remain incapable of interfering with Soviet
militarily-related space-systems, particularly those space systems
which would constitute a direct threat to Allied forces during a
conflict. These satellites are limited in number and at low
altitudes. [5½ lines not declassified]
[2½ lines not declassified] However, we
believe that the most effective way to assure the survival of
valuable US space assets in time of
crisis is, first, to reduce through appropriate technical measures
the electronic and even the physical vulnerability of US satellites and, second, to have
substantial alternative mission capabilities for the con
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duct of war. Approaches for
achieving greater survivability were addressed in NSDM 333.5
The Group believes that expeditious implementation of enhanced
survivability measures for critical space assets should be given
high priority.
There are two broad alternatives for an anti-satellite capability:
(1) physical destruction or damage, and (2) electronic
interference.
[4 lines not declassified] However, such a
capability is likely to be perceived as more provocative than
electronic interference for two reasons: (1) its effect is
irreversible and unambiguous and (2) the political consequences of
its use are likely to be more severe. Moreover, such a physical
destruction system is likely to be more expensive than an electronic
interference system.
Physical damage by radiation such as laser, microwave, or possibly
particle radiation has characteristics somewhat intermediate between
explosive kill and electronic interference. Its effects would not be
reversible, but could be ambiguous and the political consequences
less severe than in the case of explosive kill.
The Group recommends that first priority be given to developing an
early capability for electronic interference. Different satellites
have vulnerabilities to different electronic warfare techniques. The
generic techniques which may in principle be employed include noise
jamming, deception, command link capture, uplink jamming, delayed
repeater jamming, and RF burnout of electronic components. Not all
of these techniques can be employed effectively against all
satellites. Some of these techniques would be realized most
effectively with co-orbital jamming satellites, while others could
be best achieved from ground-based jammers. Specifically, some types
of radar, ELINT, and navigation satellites could be negated by
another satellite nearby which emits a noise barrage or rebroadcasts
their signals with small random time delays.
Since the operation of many satellite systems is dependent on the
frequent receipt of commands from ground stations, command link
capture or jamming represents a particular vulnerability of
satellite systems. The possibility of interfering with this link
depends strongly on the altitude of the satellite. The command link
of a low altitude satellite, such as a photo-reconnaissance
satellite, is normally only turned on to receive when the satellite
is over the Soviet ground station and is out of view of possible
jamming sites. As a result, it is more difficult to interfere with
low altitude satellites than it is to interfere with satellites in
synchronous operational orbit which are always in view.
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The Group cautions, however, that the operational problems associated
with electronic interference must be carefully controlled. US testing of such a capability can
compromise its effectiveness and would be provocative if exercised
against Soviet systems.
[1 paragraph (11 lines) not declassified]
In general the nature of the US
development program should be influenced by potential arms control
agreements as well as military requirement. However, in this case it
may not be easy to negotiate a useful and verifiable agreement
limiting anti-satellite activities. It is not clear what kind of
agreement would be in the US
interests. Given the nature of present assets, it would seem that an
agreement that would limit both the US and the Soviet Union to low-altitude ASAT capability would be desirable.
Such an agreement may be difficult to reach at present. In contrast
to the Soviets, we have no low altitude intercept capability while
their high altitude space assets are more limited than ours. In
addition, because of the limited number of targets, there is no real
distinction between an effectively deployed ASAT system and one that is still in
the test stage of development. Further, the Group does not believe
that it is practical to obtain a verifiable and useful agreement
limiting electronic interference. These various factors must be
clearly and fully understood before entering into negotiations on
ASAT limitations.
[1 paragraph (5½ lines) not declassified]
This target list places enormous technical and operational demands on
a US system. The size and
composition of the targets and the time requirements imply a
substantial system deployment including non-conus basing, in the
southern hemisphere. While the Group is not in a position to present
a definitive target list, we believe a more modest system aimed at
the critical military threat is appropriate. [2½
lines not declassified]
The size of this target set and the time requirements must, of
course, be reassessed as the composition of the Soviet satellite
fleet evolves.
A system aimed only at low-orbit interception is also suggested by
the fact that a demonstration of a high-altitude capability by the
US would encourage the early
development of a similar capability by the USSR. This would negate the current US superiority of high altitude. In
summary, proceeding with development of a low-orbit intercept system
is appropriate. The decision to undertake flight testing at a
suitable time in the development cycle should consider the status of
arms control negotiations or agreements. At present, it would be
premature to develop or demonstrate a high altitude intercept
capability.
