Re: [ft] Orbits in Vector

----- Original Message -----
From: Brian Burger <yh728@victoria.tc.ca>
To: GZG-L <GZG-L@CSUA.Berkeley.EDU>
Sent: Saturday, July 29, 2000 8:10 PM
Subject: [ft] Orbits in Vector

> Does anyone have a system for doing on-table planets and orbits
with
> vector movement?
>
> I'd kind of like to be able to do slingshot maneuvers and
similar as well,
> but they don't work in the attempts at orbital rules I've been
playing
> with...

  I'm just waiting for free time to see if the Traveller Book 2
rules actually work well for this.  I don't think, though, that
you'll be able to make a slingshot work.
     If I understand it correctly, a slingshot starts with the
ships coming from high in the gravity well.  When it gets to the
bottom (as close as it's going to get), it burns propellant, and
the momentum that the propellant acquired by "falling down the
well" stays with the ship.  Momentum = mass times velocity; since
you have the same momentum, but lower mass coming back up the
well, you have a higher velocity.  Of course, the more of your
ship's mass you burn off, the bigger your bonus.  But since FT
ships don't use consume mass for fuel, you wouldn't have any
obvious way to get a benefit.
  You could, of course, check out Keith Watt's site
(www.exodusproject.com ) and use his fuel rules.  Me, I have
enough to do to figure out the orbits in the first place, much
less play with slingshots.