GURPS Space: Stardrives

[Fred Brackin]

Originally Posted by Diomedes

I Boarding actions aren't really affected by stardrive, unless you want them to actually occur in FTL.

FTL drives can be a marvelous excuse to make almost any improbable thing you want happen.

For example, let us consider a system of hyper-sailing.

Hyperspace is an unfriendly and complicated place and ship's do very little other than keep themselves in it. To actually move they catch hyperwinds with their hypersails.

Again, all sensors are passive-only and fairly low resolution. Navigation is a system of dead-reckoning and not particularly precise. The whole thing does have the virtue of being relatively cheap.

If one hypersailor wishes to conduct hostilities against another the only possible weapon is a projectile with it's own hyperfield grid.

You could build a miniature ship with AI guidance but a simple sphere is much cheaper. You shoot it other ships with gun that uses compressed hyper-medium.

A projectile does not do actual damage to the target ship. It seeks to crash the target's hyperfield. When this happens the ship "sinks" back into normal space.

Sinking or uncontrolled re-entry is very traumatic. Sparks jump out of the control panels, magnetic fields fluctuate wildly, computers go crazy, superconducting storage loops discharge, _bad_ things happen to fissionable materials and anything with more stored chemical energy than olive oil spontaneously combusts.

Generally a ship that sinks will be "dead" in normal space for quite a while, until the doubletalk generators can be brought back on line.

Fitting a hyper-sailor with conventional weapons can be quite difficult. Small-arms ammo can be kept in explosion-proof boxes and heavier weapons can be kept in automatically ejecting compartments next to the hull but sometimes those won't work. You'll have to do without them if you sink whether your precautions work or not.

What can you carry? Hyperdense cutlasses and compressed air guns shooting monowire shurikens maybe? Unpowered armor that can protect from these things should be too massive to be attractive.

A ship that is fully confident that it will never "sink" can carry more but even a controlled re-entry probably puts some limits on that.

A pirate doesn't actually need them anyway. After he's sunken a ship back into normal space he can make a controlled re-entry and then board and storm, shiver some timbers and say "Arrr!" a great deal.

This has the benefit that ships can't assault defended planets so interstellar war is quite limited but Pirates can hunt down merchantmen and raid undefended worlds as well.

Major worlds can sit tight behind their orbital defenses but unless they send out a hyper-navy to hunt down hyper-pirates their interstellar trade will suffer greatly.

There, I think that shows that an arbitrary thing like ftl can be tailored to do almost anything you want and heavily influence the setting in other ways.

[Anthony]

Originally Posted by Diomedes

In space, "very large" will have to be measured in light-seconds.

No, it just needs to be larger than the distance to the ground. If you pop out at a hundred miles, and the jump region is a few thousand miles across, there's a good chance you can reach the ground before anything can respond.

Originally Posted by Diomedes

Getting from orbit to land undetected will be a function of whether the government can afford to cover the surface with radar. You could sneak onto a colony, but a homeworld would be much tougher.

It's not always necessary to be undetected. Just being faster than the response will do the job.

Originally Posted by Diomedes

What precisely is the objective of lower scale space travel? If space travel is too limited, so to will be colonization.

The objective is to have it so the number of ships at a port, at least in a secondary area, will be fairly small. This may not be a big problem.

[Fred Brackin]

Originally Posted by Diomedes

So you go through the portal and travel down the line until you reach the appropriate exit, or jump to a higher power line? Is there just one Alpha line that can theoretically take you anywhere if you can stay on long enough, or do you have to switch via a Beta or higher to a separate Alpha line?

In my visualization Alpha lines are just feeders to higher order lines. You'll have to make at least 2 transitions (Alpha to Beta, Beta to new Alpha) to get anywhere.

Each transition would require a Piloting roll and margin of success would determine how many revs you have to spend to get across the turbulent juncture.

Bypassing a juncture would also require Plioting and expenditure of revs though not quite so much. A hot PC Pilot should be able to go a good deal farther than a safe corporate pilot or AI on the same amount of revs.

[Diomedes]

Originally Posted by Anthony

No, it just needs to be larger than the distance to the ground. If you pop out at a hundred miles, and the jump region is a few thousand miles across, there's a good chance you can reach the ground before anything can respond.

...

It's not always necessary to be undetected. Just being faster than the response will do the job.

...

The objective is to have it so the number of ships at a port, at least in a secondary area, will be fairly small. This may not be a big problem.

Perhaps I'm not visualizing this correctly. Are you saying the only way to intercept the smuggler attempting to land would be by FTL?

[Diomedes]

Originally Posted by Fred Brackin

In my visualization Alpha lines are just feeders to higher order lines. You'll have to make at least 2 transitions (Alpha to Beta, Beta to new Alpha) to get anywhere.

Each transition would require a Piloting roll and margin of success would determine how many revs you have to spend to get across the turbulent juncture.

Bypassing a juncture would also require Plioting and expenditure of revs though not quite so much. A hot PC Pilot should be able to go a good deal farther than a safe corporate pilot or AI on the same amount of revs.

How would you go about bypassing a juncture (between the Alpha and Beta lines, I take it?)?

Edit: Or to put it another way, is there some method of accessing the higher lines besides the junctures?

[Fred Brackin]

Originally Posted by Diomedes

How would you go about bypassing a juncture (between the Alpha and Beta lines, I take it?)?

Okay, you go up the Terran trailing Alpha. You are actually moving in a corkscrew fashion up the sides of the line.

Exactly how fast you're going and how long it takes to spiral around the line is determined by expending at least a few revs from your turbo.

You come to where one swirling column of energy (the Terran trailing Alpha) meets another (the Beta). You've got to transition from one line to the other and doing this in a controlled fashion requires a Piloting roll and more revs.

Miss it and you get sent back down the Alpha. Blow it badly and you'll be going the wrong way on the Beta.

You intend to go past the Secondus juncture on the Beta and then down the Tertius line.

Ideally, you control your corkscrew movement so that when you come to the Secondus juncture you are on the opposite side of the juncture in relatively smooth territory.

You then need to control your corkscrewing so that you hit the Tertius juncture at just the right speed, angle and rotation to smoothly transition from one line to the other. Another Piloting roll and more revs.

Going down the Tertius Alpha is easy. You only need enough revs to keep your passengers from getting motion sickness.

The corkscrew motion makes it difficult but not absolutely impossible for one ship to hit another. If two ships do hit, the pieces get dumped out _somewhere_. Probably multiple somewheres, hope your lifepod is okay

After you exit the Tertius Alpha at the leading portal you can drift nearby just long enough to recharge your turbo and head for Quartius or Quintus, head for Tertius itself or bypass Tertius and travel to its' trailing Alpha which will probably take you to an entirely different area of the swirlway.

The one drawback is that mapping this thing is going to be annoyingly complex. Each portal is going to lead to its' own "tree" until (maybe) they start to link up.

[David Johnston2]

[QUOTE=Diomedes]Indeed.

Smuggling requires the ability to go "off the trail" on routes the Navy doesn't patrol – so no point-to-point. It also requires the ability to get contraband down to the planet without getting caught, which is the real bottleneck, no mater what stardrive you use.

Matter transmitters would do the trick. Then again it may not be the planet that has an objection to your transportation of said goods but some authority between the planet and the source of the contraband.

Piracy requires that the legitimate trade use those same unpatrolled routes, or a navy that is seriously under-resourced.

Well in space unless there are lots of choke points, an "under-resourced" navy is only natural. But note that piracy has been around for thousands of years and still exists to this day. As long as pirates have a secure base of operations that the navy lacks the authority or will to eliminate, they can and will operate.

[Fred Brackin]

Originally Posted by Diomedes

Edit: Or to put it another way, is there some method of accessing the higher lines besides the junctures?

No. You have to travel through the physical swirlway.

[Diomedes]

Originally Posted by Fred Brackin

No. You have to travel through the physical swirlway.

Then I'm definitely not clear as to how it would be possible to bypass a juncture.

[AstralRunner]

Bah, I open a thread with an epic title like "Stardrives" and see discussion about such piddling little devices as one would find on a spaceship. Anything deserving the appellation of "stardrive," in my view, ought to be capable of moving stars.

As for me, I use pion-rockets for my interstellar travel needs. They don't go faster than light, but they do have the advantage of being the highest-performance means of transportation that is also realistically feasible.

As the "in respect to what" question brought up by another post, I recommend the frame of reference in which the intensity of the cosmic background radiation is isotropic as the answer.