guidance, flight mechanics and trajectory optimization

(2.17)
The solutions of all of these equations are straightforward except that for
(2.17). Kepler's equation requires an iterative procedure to obtain E, .
Once the position of the target vehicle at time T is known, the
velocity required of the rendezvous vehicle at t = 0 can be found. First,
the set of equations (2.18), which constitute Lambert's theorem (see Reference
2.13) solved iteratively for a, Or , and ,& .
rlO)+~Ir, +c =4&&q
dO)+~;tr)-C =4*&P++
L (fl-Az&oc) - c/-A&/&q
Next, the eccentricity e is determined from the set
r(O)= al/-e cm< 1
I;(Z) = a//-e cm& RAE))
50
(2.18)