"Christopher M. Jones" wrote in message
...
Pat Flannery wrote:
Christopher M. Jones wrote:

The missiles Henry is talking about simply went up and
down. The reason they needed advanced flight control
systems was to get close enough to the target so that a
megaton nuke would actually do some damage to it. That
tells you the level of accuracy and sophistication we're
dealing with here.

Here are some of the Circular Error Probabilities of the first ICBM's:

(A lot of snipping)

Atlas- 2 nautical miles.

Back in the early days of Atlas missile full range testing with active radio
guidance
when everything worked the warhead was falling into a .5 nautical mile
circle most of
the time and within .25 nm quite often. If things went seriously wrong the
warhead
ended up nowhere near the target.

Command guidance was regarded as undesirable because of vulnerability to
enemy countermeasures so there was a shift to interial guidance systems.
The
figures I saw on this were 5-10 nm. Quite close enough for soft targets
such as
cities. Not good enough for taking out launchers in silos.

This is circa 1960and inertial guidance systems became much more accurate
later. One of the biggest advances in target accuracy was achieving more
accurate
mapping. If you don't know where you really are at the launch point and
don't know
exactly where the target is then accuracy is just a bit hard to achieve.

I bet Henry Spencer could give us a real lecture on this.

Mike Walsh