4 ms·

Mach 10 is almost too fast to be hypersonic! Hypersonic is the range around Mach 5-8. There are various types of ballistic missiles that go faster than this (a

Mach 10 is almost too fast to be hypersonic! Hypersonic is the range around Mach 5-8. There are various types of ballistic missiles that go faster than this (and have been doing for decades) but since they are old they aren't as sexy as "hypersonic missiles".

superkuh 4y ago
The new thing is trying to go hypersonic in the atmosphere for more than a couple minutes so you can use it for lift. But either there's too much heat or not enough lift.
- jasonwatkinspdx 4y ago
  No, this is in fact not categorically new. MaRV and related demonstrated 60 G pull up to horizontal glide maneuvers. The technology of a HGV and a maneuverable re-entry vehicle are essentially the same. The main reason for talking about "hypersonics" as a separate category today is to emphasize flight profiles that would not be interpreted as nuclear strikes.
  - littlestymaar 4y ago
    As I understand it, it's not about “not being interpreted as nuclear strike” — since almost every Russian missile (including anti-ship missiles like Kh22 and the likes) could potentially carry a nuclear warhead, they explicitly don't care about the ambiguity, while the Western doctrine is diametrically opposite, explicitly aiming for as little ambiguity as possible to keep the escalation risk low. And your interpretation basically goes against both doctrines. — But more about keeping a low trajectory so that the missile stays below the early-warning radar horizon for most of its flight, striking without warning, where a ballistic missile gets within the LOS of radars quite early due to its trajectory.
  - superkuh 4y ago
    Yeah, ICBMs have slightly glidy, menuevering entry vehicles. But these don't fly. It's more like falling with style. And they certainly don't have shapes that aren't simple conicals. Otherwise the heat from compression and where the shockwaves impinge on the complex structure completely overcomes materials tech and any possible heat soak or re-radiation.

superkuh 4y ago

The new thing is trying to go hypersonic in the atmosphere for more than a couple minutes so you can use it for lift. But either there's too much heat or not enough lift.

jasonwatkinspdx 4y ago
No, this is in fact not categorically new. MaRV and related demonstrated 60 G pull up to horizontal glide maneuvers. The technology of a HGV and a maneuverable re-entry vehicle are essentially the same. The main reason for talking about "hypersonics" as a separate category today is to emphasize flight profiles that would not be interpreted as nuclear strikes.
- littlestymaar 4y ago
  As I understand it, it's not about “not being interpreted as nuclear strike” — since almost every Russian missile (including anti-ship missiles like Kh22 and the likes) could potentially carry a nuclear warhead, they explicitly don't care about the ambiguity, while the Western doctrine is diametrically opposite, explicitly aiming for as little ambiguity as possible to keep the escalation risk low. And your interpretation basically goes against both doctrines. — But more about keeping a low trajectory so that the missile stays below the early-warning radar horizon for most of its flight, striking without warning, where a ballistic missile gets within the LOS of radars quite early due to its trajectory.
- superkuh 4y ago
  Yeah, ICBMs have slightly glidy, menuevering entry vehicles. But these don't fly. It's more like falling with style. And they certainly don't have shapes that aren't simple conicals. Otherwise the heat from compression and where the shockwaves impinge on the complex structure completely overcomes materials tech and any possible heat soak or re-radiation.