Robot warfre IN SPACE!

[Fred Brackin]

Originally Posted by lwcamp

I am not familiar with Battlestar Galactica, so I don't know what funny tactics their jump drives allow.

BSG used a Jump drive that was a simple "blink" and you're there but with semi-limited accuracy. No pinpoint jumping anyway.

You also had to "spin up the drives" and "calculate the Jump" which took a significant period of time. In an early epsiode the Fleet (which was msotly civilian ships) needed 33 minutes to go therough the process. So no "blink and and blink right back out" either. Unless maybe you performed a highly risky "blind jump".

My assumption on hearing "like BSG" would be that you could Jump into a known astronomical position or one that a scout ahd jumped back and told you about. So you're either don't know the tactical situation at your arrival point or you're working with at least slightly delayed data.

Limited tactical use of Jump except when the writers thought they needed to break the rules.

[lwcamp]

Originally Posted by Fred Brackin

BSG used a Jump drive that was a simple "blink" and you're there but with semi-limited accuracy. No pinpoint jumping anyway.

You also had to "spin up the drives" and "calculate the Jump" which took a significant period of time. In an early epsiode the Fleet (which was msotly civilian ships) needed 33 minutes to go therough the process. So no "blink and and blink right back out" either. Unless maybe you performed a highly risky "blind jump".

This indicates to me that all action will be in planetary orbit. There will be no need to transition into solar orbit to get to your objective - just jump and you are there. Unfortunately, maneuver in planetary orbit is going to be significantly more difficult to model than maneuver on crossing solar orbits, although if you are familiar with orbital dynamics you could be able to abstract a lot of this. Unlike intercept combat in deep space, in planetary orbit you will be making pass after pass by your target. At TL 9 your ability to significantly change orbits will be severely limited (except via the superscience jump).

There's also the issue of your velocity vector after the jump. Are you screaming along at many times escape velocity, about to go sailing off into the void and never return? Are you at rest with respect to the planet (and about to fall into it if you don't apply some delta-V real soon)? Can you adjust the velocity so you are in a convenient circular orbit (or other orbit of your choice)?

Luke

[MrBackman]

Originally Posted by lwcamp

<snip>At TL 9 your ability to significantly change orbits will be severely limited (except via the superscience jump).

There's also the issue of your velocity vector after the jump. Are you screaming along at many times escape velocity, about to go sailing off into the void and never return? Are you at rest with respect to the planet (and about to fall into it if you don't apply some delta-V real soon)? Can you adjust the velocity so you are in a convenient circular orbit (or other orbit of your choice)?

Luke

A TL 9 Fusion engine will allow you to change orbit at will, but it will take some time to do so, a single fueltank gives roughly twice the escape velocity from Earth so you can buzz around changing orbit to your hearst desire, albeit slowly.

As for the delta-V of jumps, nearly all jumpdrives silently ignores the problem of relative velocities between systems (Poul Anderson's World without stars being the exception I can come up with), a neat handwave to use to invoke a Machian field. Mach, and many scientists then and now (including Einstein) believed that inertia is caused by surrounding matter. You can posit that there is an Machian field that will retain the relative velocity visavi massive objects as one jumps, massive objects like planets. At rest versus earth when jumping means at rest versus mars when exciting, the change in translational momentum taken up by the surrounding universe. Whether you tell your players about the fictional Mach field or simply ignore the problem is up to you and your players, for me it works at least.

For a technical discussion on how Traveller jumpdrives might work you can read my Hyperspace for dummies article.

World without stars described a jumpdrive that could only jump to stars with nearly identical relative velocities. That meant that relatively few stars were accessible from Earth but some of them would be ver far indeed, good stuff as always from the master of planet building.