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0 pointsarijun3y ago0 comments

The article said ICBMs were hypersonic, and those certainly spend a lot of time outside of the atmosphere.

The gliders seem to spend the entirety of their trip in the upper atmosphere, though.

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Reentry does kind of by definition enter the hypersonic regime, but it's somewhat unintuitive to the layperson since Mach 5 is much slower at those very low pressures, and it's an entirely different beast than flying at Mach 5 in-atmosphere proper

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