Rendezvous in space

There's something that I've been wondering about recently, especially
after reading Jim Oberg's piece in the current edition of Ad Astra
magazine.

I understand, as well as any layman might understand, the mechanics of
orbital rendezvous. How counter intuitive it appears. Does the same
type of problem exist if two space craft were trying to rendezvous
either en route to SEL 2 or anywhere else whilst traveling in an almost
linear direction comparatively speaking? (I know that you'd still be in
solar orbit)

Are the motions involved the same for this kind of rendezvous or does a
totally new set of paradigms take over?

Thanks
Rich Godwin
Apogee Books

The math is the same, but the smaller the gravitational field, the
closer to a straight line the trajectories will be. In other words, if
you are far from a massive body like the Earth or Moon and with a given
distance between vehicles with equal velocities, rendezvous simplifies
to "catching up" like cars on a stretch of highway on Earth.

Lee Valentine wrote:
The math is the same, but the smaller the gravitational field, the
closer to a straight line the trajectories will be. In other words, if
you are far from a massive body like the Earth or Moon and with a given
distance between vehicles with equal velocities, rendezvous simplifies
to "catching up" like cars on a stretch of highway on Earth.

There are perterbations which affect things - especially in a low gee
condition. Small variations will cause an effect, especially if
repeated regularly. The orbital period of objects will induce this
regularity. This has an impact on long-term stabiilty of an orbit as
well as rendezvous and station keeping. Two objects in nearly the same
orbit, with a period of say 100 minutes, will dance around one another
every 100 minutes because of these effects.

Edwin Aldrin did his masters thesis on these minor aspects of orbital
mechanics that turn out to be quite useful. This was one reason he was
chosen for the Apollo 11 moonshot.

The only one I really recall from courses I took that I can site as an
example is the sun-synchronous polar orbit. Here the equatorial bulge
of the Earth introduces a periodic variation in the gravity a polar
orbiting satellite feels - which induces a precession in the orbit -
which can be modulated by relating inclination and altitude - so that
the orbital plane remains constant relative to the sun throughout the
year. This means the satellite rises and sets the same time each day -
keeping solar time. This has certain advantages in sensing and
communications applications.

http://en.wikipedia.org/wiki/Astrodynamics
http://www.braeunig.us/space/orbmech.htm

I've tried to look up Aldrin's Master's Thesis - I merely got some
references to it in the New Yorker following his return from the moon.

Anyway, good luck with your book! I have been a purchaser of many of
them and enjoyed them thoroughly.