ballistic ones are faster, but reach Mach 20 and similar speeds outside of the atmosphere
This seems notable, since there is no sound w/o atmosphere. So perhaps ballistic missiles never actually engage in hypersonic flight, despite reaching speeds that would be hypersonic if in the atmosphere? Though I would be surprised if they’re reaching Mach 20 at a high altitude and then not still going super fast (above Mach 5) on the way down.
Exactly, ballistic missiles (or, at this point of the strike, their warheads) are slowed down when reentering the atmosphere—just like satellites and space capsules containing astro/cosmo/spationauts—at much slower speeds. The 2-digit Mach speeds are reached only outside of the atmosphere.
This seems notable, since there is no sound w/o atmosphere. So perhaps ballistic missiles never actually engage in hypersonic flight, despite reaching speeds that would be hypersonic if in the atmosphere? Though I would be surprised if they’re reaching Mach 20 at a high altitude and then not still going super fast (above Mach 5) on the way down.
Exactly, ballistic missiles (or, at this point of the strike, their warheads) are slowed down when reentering the atmosphere—just like satellites and space capsules containing astro/cosmo/spationauts—at much slower speeds. The 2-digit Mach speeds are reached only outside of the atmosphere.