electric lasers these days.
Elaborate on "electric"
Ken
On Thu, Oct 15, 2020 at 1:41 PM Henry Vanderbilt <hvanderbilt@xxxxxxxxxxxxxx>
wrote:
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>
<troy@xxxxxxxxxxxxxxxxxxxxx> wrote:
attracted a lot of attention and hype but had no military value
whatsoever.
(For the sponsoring nation, that is -- it had considerable value to their
enemies,
since it pulled desperately-scarce resources away from things that *did*
have
real military value.) The recent hypersonics hype smells much the same to
me...
Henry
I guess the difference now is the "enemy/ies" are all on the same hypersonic
bandwagon.
Troy