In article ,
John Schilling wrote:
If either the initial or the destination orbit is noncircular, or if
third-body effects are involved, the situation gets rather complex
and is not amenable to analytic solution.

There are *some* analytical results for non-circular orbits, but they
don't add up to a useful complete picture.

For example, there is an analytical result for the low-thrust delta-V for
escape from an elliptical orbit using tangential thrust (along the
velocity vector), and another for the optimal thrust direction for escape
from an elliptical orbit, but they don't match up -- the optimal thrust
direction is *not* tangential. (This is actually true even for circular
orbits, but there the differences in both optimal direction and resulting
delta-V are almost negligible. For elliptical orbits, the differences are
too large to ignore.)
--
MOST launched 30 June; first light, 29 July; 5arcsec | Henry Spencer
pointing, 10 Sept; first science, early Oct; all well. |