phil@shadow.Berkeley.EDU (Phil Lapsley) (01/16/88)
The July '86 issue of IEEE _Spectrum_ had a special report section entitled
"Peacekeeping by Technical Means" (pp. 42-80). On pp. 48-49, there is
a discussion of the KH-12 spy satellite:
"The newest addition to the U.S. reconaissance repertoire, the
KH-12, is a craft so big that it can not be hurtled into space by the
Titan 34D. It reportedly will render both Big Bird [the KH-9] and
the KH-11 obsolete; its resolution of objects on the earth may be
less than 10 centimeters. Only the space shuttle can lift this four-
story-high satellite into space, and the job will likely draw on its
maximum lift capacity. The KH-12 is scheduled to be one of the first
customers when the orbiter resumes flying. (The air force is also
building a Titan 34D7 rocket, projected to be ready by 1988, that could
lift shuttle payloads the size of the KH-12.)"
"Because the KH-12 program is highly secret, a new civilian
project, the National Aeronautics and Space Administration's Hubble
Space Telescope, provides the best example for estimating the level of
today's space surveillance technology. [...] John Pike, associate
director for space policy at the Federation of American Scientists in
Washington, D.C., called the space telescope an unclassified version of
the KH-12. [...] Because the KH-12, like the telescope, must fit in the
shuttle cargo bay, it probably has no larger than the 2.4 meter primary
optics of the space telescope."
[several paragraphs deleted.]
" ... but if the telescope were designed to be less sensitive
[to reflected light from Earth] and turned toward the globe from an
orbit equivalent to that of the KH-11 reconaissance satellite, a simple
calculation shows that its theoretical ground resolution would be 7.16
cm, or just under three inches." [They refer to the well-known IEEE
"back of the envelope calculation" sidebar, which has a picture of an
envelope and the following notations:
"Resolution = (altitude / focal length) * diameter of pixel
Given: typical perigee of KH-11: 275 km,
focal length of space telescope: 57.6 m,
pixel size: 15 microns,
then resolution = 7.16 cm."]
"The calculations are based on the telescope's existing optical
system and its wide-field and planetary camera, which uses eight arrays
of charge-coupled devices for near-instantaneous imaging. Each array is
composed of 800 by 800 picture elements; each pixel is 15 microns across.
The effective focal length of the Perkin-Elmer optical system is 57.6 meters.
Officials at Lockheed added that the designers of the space telescope,
on which optical assembly began in the mid-1970s, made us of existing
technologies rather than pushing the state of the art."
"The estimate of theoretical resolution corresponds to what several
knowledgeable sources have told _Spectrum_: actual resolution on current
U.S. reconnaissance satellites is sharp, but not capable enough -- even
under the best platform stability and atmospheric conditions -- to
distringuish whether a man sitting in Red Square is reading _Pravda_
or _Izvestia_. The bold front-page logos of the two Soviet newspapers
are slightly smaller than the numbers of a typical auto licence plate
[Figure 3 shows a picture of a VW bug using a camera intentionally
unfocused to have about a 7 cm resolution.]. This also does not conflict
with what has been publically stated about resolution capabilities.
Former CIA director Colby told a Senate committee in 1979, "You can see
the tanks, you see the artillery, but you may not quite see the insignia
on the fellow's uniform."
There is more, but my fingers grow tired. I recommend the July '86
issue of _Spectrum_ in particular (I recommend _Spectrum_ in general)
to anybody interested in more details.
Phil