There was this question in the book, at which place on the elliptic orbit the body has maximum acceleration. Since acceleration is proportional to force, a = GM/r^2, this should happen when the distance r is minimum, this is when the planet is at perihelion. But the contradiction is that at perihelion the body (or satellite) has its maximum speed, that means that it no longer accelerates to increase speed. To explain this I would guess that at this point acceleration changes direction and begin slowing the satellite down. Is that really what happens?