[cespare]

I was trying to understand how an altitude of 470,000 ft compares to other things, so I looked up a few numbers.

470k feet is 143 km. The altitude record for an air-breathing aircraft is 38 km. There are some very low earth orbit satellites that orbit in the sub-200 km range (https://en.wikipedia.org/wiki/Very_low_Earth_orbit). The ISS orbits at about 400 km and typical LEO is 800 km. ICBMs have an apogee altitude of 1000 km or more.

(Of course, the energy required to get up to some altitude is only a small fraction of the energy required to get into orbit at that altitude. https://what-if.xkcd.com/58/ is a relevant read.)