Utility in evading missile defenses aside, one thing to keep in mind is,
for certain targets - among them ships - payload fraction is less
important. A hypersonic impact delivers TNT-equivalent energy for the
entire vehicle mass involved even with no actual warhead on board at
around Mach 9, and the equivalent energy of a 25%-of-vehicle mass TNT
warhead at Mach ~4.5.
Given that the main penetrating-defenses advantages seem to be
maneuvering beyond an interceptor's ability to follow, and operating in
atmosphere bands where the interceptor loses effectiveness, effective
anti-missile beam weapons will likely negate much of those advantages
and largely obsolete expensive hypersonics. Which may well explain why
USN (and USAF) seems very interested in electric lasers these days.
Henry
On 10/15/2020 2:23 AM, George Herbert wrote:
OT...
It’s not much of a secret I do missiles and nuclear proliferation research and
analysis including threat systems analysis as a side job.
There are a few things you can do with hypersonic weapons. You can approach
targets in the inconvenient altitude and speed band where there’s too little
lift for normal fins and too much for unstreamlined exoatmospheric
interceptors. Midcourse defense gets very difficult... You can change
direction in hypersonic flight, allowing flightpaths avoiding defenses or
attacking simultaneously from different directions, complicating defenses.
Under some circumstances they can use trajectory changes in target approach to
maneuver out of interceptor engagement envelopes after interceptor burnout.
Against rapidly maneuvering targets there is a better target volume capability.
Under some circumstances the range is longer than a smaller ballistic
trajectory Maneuvering Reentry Vehicle can do.
They are much more expensive and harder to do than maneuvering ballistic RVs.
They can’t carry effective decoys, IR sensors see them thousands of kilometers
away, and avoiding defenses has to be done essentially blind because they can’t
credibly detect incoming interceptors with onboard sensors.
The payload fraction of ballistic RVs is about 0.5, of maneuvering RVs 0.3-0.4,
of hypersonic glide weapons 0.2 or less and Hypersonic cruise weapons 0.1 or
so. For the same payload they’re tremendously larger missiles to start with,
with corresponding ship, aircraft, submarine, truck, or silo capacity issues.
They make better sense as Chinese antiship Missiles than as US prompt
conventional strike missiles. The countries don’t have analogous needs.
-george
Sent from my iPhone
On Oct 14, 2020, at 10:19 PM, Troy Prideaux <troy@xxxxxxxxxxxxxxxxxxxxx> wrote:
attracted a lot of attention and hype but had no military valuewhatsoever.
(For the sponsoring nation, that is -- it had considerable value to theirenemies,
since it pulled desperately-scarce resources away from things that *did*have
real military value.) The recent hypersonics hype smells much the same toI guess the difference now is the "enemy/ies" are all on the same hypersonic
me...
Henry
bandwagon.
Troy