[Spirochete]

[It should move so quickly through the atmosphere — about 20 times the speed of sound...]

I’m skeptical. That’s nearly orbital velocity.

[Carl Vehse]

"It should move so quickly through the atmosphere — about 20 times the speed of sound — at such low altitudes that it's impossible for enemy missile defense systems to shoot out of the air."

But what if the enemy has a laser defense system? Laser light can travel at over 870,000 times the speed of sound.

[GardenerForLife]

[It should move so quickly through the atmosphere — about 20 times the speed of sound...]

Total nonsense.

That's re-entry velocity. Mach 20, really?

hypersonic is mach 5. The SR71 would heat up at Mach 3+. And this thing will go Mach 20...with no issues. Riiight.

[LS]

We got em.

In 1985 we were getting a scramjet up to Mach 8.