Starting with conservation of energy and angular momentum, we derive a convenient method for
determining the periapsis distance of an orbiting object, by expressing its velocity components in
terms of the local circular speed. This relation is used to extend the results of our previous
paper, examining the effects of an adhesive inelastic collision between a projectile launched from
the surface of a planet (of radius R ) and an equal-mass satellite in a circular orbit of radius r s
. We show that there is a maximum orbital radius r s ≈ 18.9 R beyond which such a collision cannot
cause the satellite to impact the planet. The difficulty of bringing down a satellite in a high
orbit with a surface-launched projectile provides a useful topic for a discussion of orbital angular
momentum and energy. The material is suitable for an undergraduate intermediate mechanics course.