Newsgroups: sci.military.moderated
From: carey.sublette@gte.net (Carey Sublette)
Subject: Re: Cruise missile vs. Ballistic missile (Was Re: naive missile que...
Date: Wed, 30 Jun 1999 17:42:58 GMT

In article <FDJD3J.I24@law7.daytonoh.ncr.com>,
ljelmore@montana.campuscw.net says...
>
....
> >
> >   Third, decoys are a problem, but with proper RF and IR discrimination,
> > you can distinguish the RVs from the decoys.
>
> And once the RVs begin re-entering the atmosphere, all the decoys fall
> rapidly behind (since they're just balloons, basically, and are much lighter
> than a real RV).

The decoy problem is a much more difficult problem than you give it
credit for. The implicit assumption you make is that only the simplest
first generation decoys will ever be deployed, whereas far more
sophisticated ones are already in service (the British Chevaline system
for one).

First off, with good system design it should not be possible to use RF
or IR discrimination in the exoatmospheric regime. The threat
nation can tailor both the RV and the decoy to have an identical
signature. Simply encasing the actual RV in an identical mylar balloon
as used with the decoys would ensure that they are indistinguishable,
and should subtle differences exist (possibly in IR signature due to
small temperature differences), it would be useless for an ABM system
since they differences would have to known in advance, and programmed
into the system. Even if test flights are closely observed by the U.S.,
and it is possible to identify decoy vs RV signature discriminants,
significantly different "wartime" signatures of the actual deployed
systems would be make it most unlikely that clever discrimination
algorithms - if any are developed - would actually work in practice. A
systematic discrimination failure, like one that incorrectly classifies
all RVs as decoys would render the whole system utterly useless.

Second, with a higher weight penalty decoy effectiveness can be extended
into the atmosphere, as the Chevaline does. Using a (mostly) empty
heatshield, supplemented by a rocket to offset the effects of drag
creates a convincing decoy that is effective well into the upper
atmosphere. Fewer can be carried obviously, but several can be used for
each RV replaced from the payload. Multiplying the number of
interceptors the defender must deploy and fire by, say, three or four,
nearly triples or quadruples the cost of the deployed system at minimal
cost to the attacker.

Carey Sublette