The well-known problem of minimizing the total characteristic velocity of a
spacecraft in an impulsive rendezvous with a satellite in circular orbit i
s considered by using the Clohessy-Wiltshire equations. It is well known th
at, for boundary conditions in the plane of the orbit, four impulses at mos
t are required. The mathematical framework is presented for four-impulse op
timal rendezvous near a circular orbit resulting in relatively simple formu
las that determine if four impulses are required and, if so, how the four o
ptimal velocity increments can be calculated.