  Using an analogy between the density expansion of the transport coefficients
of moderately dense gases and the inverse-Knudsen-number expansion of the drag
on objects in nearly free molecular flows, we formulate the collision integrals
that determine the first correction term to the free-molecular drag limit. We
then show how the procedure can be applied to calculate the drag coefficients
of an oriented disc and a sphere as a function of the speed ratio.
