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US hypersonic missile fails in test- 2nd consecutive failed attempt

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Re: US hypersonic missile fails in test- 2nd consecutive failed attempt

#41

Post by Victerius »

jeffbee wrote: post #24
swamp40 wrote: post #7

Earlier quoted context omitted.

Russia already has hypersonic. And there is no realistic defense against them. They scare the crap out of DC because a Russian sub could pop up off the coast of New Jersey and 5 million people including 99% of all US politicians would be dead 6 minutes later. So of course the US needs them.

This seems irrelevant. It has been conclusively demonstrated that the U.S. (like everyone else) lacks any kind of meaningful ready air defense. Some trucker crashed a Cessna into the White House, and DCA flights pass within 5km of the Capitol. If you wanted to decapitate the U.S. you wouldn't need a submarine, you'd just load your weapon into a 747 and file a flight plan for DCA. Nobody will stop you.

Oh boy, this comment is all kinds of wrong.

Everything changed after 9/11. There is a permanent Flight-Restricted Zone above the capital now.

Re: US hypersonic missile fails in test- 2nd consecutive failed attempt

#42

Post by Symmetry »

superkuh wrote: post #14
edenceover wrote: post #5

Given that the bomber gap, missile gap and the cruiser gap was all shown to be fictional, I do wonder if the perceived hypersonic gap is real.

Correct. No one has "real" hypersonic missiles that travel in the atmosphere for extended periods(*1). The heating problems for shock impingment in non-"simple conicals" has *not* been overcome and won't be. "Hypersonic" missiles are mostly just ICBMs with a very brief passage through the dense lower atmosphere where there's enough lift. And if they try to go higher up to escape the heat flux there's not enough for l…

Like the Pershing IIs the US deployed in 1983. https://en.wikipedia.org/wiki/Pershing_II

Re: US hypersonic missile fails in test- 2nd consecutive failed attempt

#43

Post by jandrewrogers »

edenceover wrote: post #5

Given that the bomber gap, missile gap and the cruiser gap was all shown to be fictional, I do wonder if the perceived hypersonic gap is real.

The US has a lot of experience designing hypersonic missiles -- I remember when they were testing various material configurations in hypersonic guided missiles 30 years ago. Some of those platforms exist as operational systems today. Design of hypersonic missiles is largely limited by material physics and configurations thereof. The US ability to fabricate unique exotic materials allows them to search a much larger part of the performance and capability phase space before settling on a production design.

Historically, most of the bugs in new US hypersonic designs stem from an unwillingness to sacrifice terminal guidance performance for the sake of velocity. Sensor packages rapidly and unavoidably disintegrate due to atmospheric ablation in-flight, which makes terminal guidance very difficult (because your sensors barely work by the time they get to the target). Anyone can build a hypersonic missile if you are willing to forego high-quality terminal guidance, and most do. This is an extremely difficult engineering problem when operating at the fundamental limits of material physics but the US has been unwilling to field systems that don't address it.

Re: US hypersonic missile fails in test- 2nd consecutive failed attempt

#44

Post by nabla9 »

Hypersonic is very unfortunate term, because it makes people assume that hypersonic speed is the new thing in these.

X15 was manned hypersonic vehicle in 1959. Pershing II had maneuverable hypersonic re-entry vehicle in the 80s. ICBM's are hypersonic or high hypersonic. Space shuttle was a hypersonic glider, so is X-37 currently operated by the US Space Force.

Re: US hypersonic missile fails in test- 2nd consecutive failed attempt

#45

Post by JDulin »

One problem with these hypersonic endeavors and DOD development in general is there are too few tests (And done too slowly) to iterate. The developers do not get lots of opportunities to learn from real-data, like at SpaceX. Instead, there are low-single-digit numbers of tests with tons of political attention ready to pounce at the smallest (And most common!) failure.

Re: US hypersonic missile fails in test- 2nd consecutive failed attempt

#46

Post by dylan604 »

midislack wrote: post #36

Small one didn't work so we're making a big one instead. Sheesh.

There are times when this makes perfect sense. Increasing size can make other things easier even if it takes more things like weight/fuel/size/etc. Making things small that work will sometimes add complications/complexity that otherwise could be avoided.

Re: US hypersonic missile fails in test- 2nd consecutive failed attempt

#48

Post by dylan604 »

Hayvok wrote: post #29
swamp40 wrote: post #7

Earlier quoted context omitted.

Russia already has hypersonic. And there is no realistic defense against them. They scare the crap out of DC because a Russian sub could pop up off the coast of New Jersey and 5 million people including 99% of all US politicians would be dead 6 minutes later. So of course the US needs them.

“Mutually assured destruction” is still the defense in this particular case. Anybody who thinks that America wouldn’t retaliate and turn half of east-Asia into a sheet of radioactive glass is kidding themselves.

Does MAD still work if the person threatening the first strike is a literal mad man that is suffering a terminal illness knowing their time is short anyways?

Re: US hypersonic missile fails in test- 2nd consecutive failed attempt

#49

Post by jeffbee »

Victerius wrote: post #41
jeffbee wrote: post #24

Earlier quoted context omitted.

This seems irrelevant. It has been conclusively demonstrated that the U.S. (like everyone else) lacks any kind of meaningful ready air defense. Some trucker crashed a Cessna into the White House, and DCA flights pass within 5km of the Capitol. If you wanted to decapitate the U.S. you wouldn't need a submarine, you'd just load your weapon into a 747 and file a flight plan for DCA. Nobody will stop you.

Oh boy, this comment is all kinds of wrong. Everything changed after 9/11. There is a permanent Flight-Restricted Zone above the capital now.

Yes, DIRECTLY above the Capitol. But: https://flightaware.com/live/airport/KDCA

Re: US hypersonic missile fails in test- 2nd consecutive failed attempt

#50

Post by jjoonathan »

Victerius wrote: post #41
jeffbee wrote: post #24

Earlier quoted context omitted.

This seems irrelevant. It has been conclusively demonstrated that the U.S. (like everyone else) lacks any kind of meaningful ready air defense. Some trucker crashed a Cessna into the White House, and DCA flights pass within 5km of the Capitol. If you wanted to decapitate the U.S. you wouldn't need a submarine, you'd just load your weapon into a 747 and file a flight plan for DCA. Nobody will stop you.

Oh boy, this comment is all kinds of wrong. Everything changed after 9/11. There is a permanent Flight-Restricted Zone above the capital now.

and anyone who has walked around DC in the last 20 years can attest to the missile trucks they conspicuously park around the place.
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