Yeah, I agree, NASP most definitely had the wrong approach if they thought
flying low and fast with a dynamic pressure of 2700 psi was the way to
Orbit. Better to fly high with a low "Equivalent Airspeed" that continues
to decrease all the way to Orbit. Almost universally, research in this area
is more about weapons development and not developing a cargo vehicle.
https://en.wikipedia.org/wiki/Rockwell_X-30
On Sun, May 26, 2019 at 10:28 AM Henry Spencer <hspencer@xxxxxxxxxxxxx>
wrote:
As witness NASP, trying to airbreathe almost all the way to orbit, which
ended up -- even just on paper -- needing close to 14km/s of delta-V just
to reach LEO.
Not to mention little engineering challenges like a peak dynamic pressure
of 2700psf (supersonic at sea level is 2200), and a need to circulate
high-pressure LH2 through the skin for cooling.
At Mach 15, the atmosphere is not your friend.
