Take the 2-minute tour ×  I have read and heard in many places
that when the astronauts of Apollo were coming back to Earth,
they had to determine the best angle of attack to re-enter the
atmosphere. This is usually indicated with an angular window.  I
understand that if they approached the atmosphere head-on, their
ship would have probably overheat due to the friction and burn
up in the atmosphere. I am also aware of a "skip re-entry"
method where the pilot actively controls the ship during re-
entry to bleed off momentum, exit the atmosphere, and then begin
the final entry.  My question is regarding the "skipping" effect
that this site mentions:  Like a fast stone skimming across a
pond, Apollo spacecraft would have simply bounced off the earths
surface if the angle of attack was too shallow.  My (minimal)
understanding of fluidics intuits me to believe that given the
sparse density, the exosphere would not act as a non-newtonian
fluid, that the friction would not "bounce" the craft. Keep in
mind, I'm asking