Space Campaign, revisited

[combatmedic]

A little update....

I've been reading an anthology for inspiration- The New Space Opera, editor is Gardner Dozois. It's got some Alistair Reynolds, Stephen Baxter,etc in it. Pretty good stuff.

Anyhoo, I've been giving some thought about the faster sorts of STL drives, for trips when FTL isn't possible or isn't safe [such as between unconnected jump points, within a solar system if being to close to big objects is a hindrance to FTL,etc]. I like the antimatter torch drive, and also the Bussard ramscoop. You guys think a ramscoop would work in a region of space like a nebula, where there was more stuff for it to suck up?

I've also been looking at various designs of ships that use thrust and spin to provide ''artificial gravity''- since I am leaving gravitics out of this particular universe. I like the technical box style, and also the whole ''flying skyscraper with 'gravity' provided by thrust from a really powerful drive [like a torch drive]. Those cool looking Earth ships from B5, with the rotating mid section- yeah, something like that may work its way in, as well.

I'm pretty much using all the cool space habitats that don't require god-tech.

[thtraveller]

Originally Posted by combatmedic

Anyhoo, I've been giving some thought about the faster sorts of STL drives, for trips when FTL isn't possible or isn't safe [such as between unconnected jump points, within a solar system if being to close to big objects is a hindrance to FTL,etc].

Yup. Even limited superscience fusion torch drives take a while to get around - typically over a month between planets (like Earth-Mars). You need to go to TL11 to get it down to a couple of weeks.

Or allow in-system micro-jumps to planets.

I like the antimatter torch drive, and also the Bussard ramscoop. You guys think a ramscoop would work in a region of space like a nebula, where there was more stuff for it to suck up?

It certainly adds techno-babble why it might. Though nebula is probably very patchy stuff.

[Rasputin]

Originally Posted by combatmedic

A while back, I did some work on a GURPS Space campaign setting. I set that aside to work on other projects, and am now ready to return to it.

I'm going to sart by laying out a basic set of guidelines. This is intended to have some retro elements.

Time? Not sure, but far enough in the future for there to be multiple colony worlds, some settled for at least a couple of centuries.

Technology: The dominant human civilization[s] = TL 10, leaning towards safetech. I don't want to emphasize transhumanist stuff, although bionic limbs and the like will exist. No nanofacs/replicators. No contragrav. No reactionless drives. FTL travel is via a web of interconnected jumplines, using a jump drive. No FTL radio, so courier ships are used instead. Only limited superscience, mainly in the form of FTL.

Aliens- Multiple species, several of which are not humanoid. Life on most planets shares certain fundamental similiarites to life on Earth- suggestive of a common origin. Some people explain this in scientific terms, others turn to religion for answers.

Magic, Psi, etc- Nope. Danger sense or luck is fine, telepathy and TK are right out. That doesn't mean there aren't people who believe in this stuff, of course.

I ran a game under similar conditions (I didn't use much in the way of aliens, however, and I did have psi, which was mandatory for the jump drive). One thing that helped me was GURPS Space Atlas, which gave me a ready supply of worlds.

[Figleaf23]

Originally Posted by combatmedic

Maybe I should switch the instant jumps for slow jumps- like in Traveller? That would slow down communications nicely.

Classic space pirates are not absolutely necessary to the setting, really. Some pirates may raid planets, not ships- Space Vikings! Raiding an enemy world may get overlooked by friendly port authorities [or ones you've bribed].


Keep in mind there is not a single star empire controlling all these various jumplines.

Edited previous post to reflect this question of time involved in jumps.

The power of maneouvre drives and ship-detection technology will be important in whether pirates can stake out asteroid belts etc. in-system and prey upon ships travelling to and from jump points.

[combatmedic]

Originally Posted by Figleaf23

The power of maneouvre drives and ship-detection technology will be important in whether pirates can stake out asteroid belts etc. in-system and prey upon ships travelling to and from jump points.

Good point. Pirates will want fast ships with good long range sensors- warships, in other words. Maybe some of the pirates will be leftovers from the losing side of an interstellar conflict.

[combatmedic]

Originally Posted by thtraveller

Yup. Even limited superscience fusion torch drives take a while to get around - typically over a month between planets (like Earth-Mars). You need to go to TL11 to get it down to a couple of weeks.

Or allow in-system micro-jumps to planets.


It certainly adds techno-babble why it might. Though nebula is probably very patchy stuff.

Well, I might go to TL11 for some tech, but probably not. A month between Earth and Mars is fine. I'll want some lag in communications and transit time, to keep the right feel for the setting.

[Figleaf23]

Originally Posted by combatmedic

... A month between Earth and Mars is fine...

Be careful, though -- in system distances jump up quick sharply as you move out of the inner area. Earth-Mars might be okay at a month travel time, but if you've got people out on Saturn's moons, you're looking at many months at that speed.

Also, consider whether that Earth-Mars month is when they are close in thier respective orbits or whether they're around the sun from eachother.

[thtraveller]

Originally Posted by Figleaf23

Be careful, though -- in system distances jump up quick sharply as you move out of the inner area. Earth-Mars might be okay at a month travel time, but if you've got people out on Saturn's moons, you're looking at many months at that speed.

Also, consider whether that Earth-Mars month is when they are close in their respective orbits or whether they're around the sun from each other.

With this fusion torch scout ship, with hydrogen fuel (rather than water), the Earth-Mars travel time is 36 days (that is orbit to orbit, median distance of 1.8 AUs, with full tanks)

200 days to do the 10 AUs to Saturn.

At TL11 this goes down to 13 days and 67 days respectively. Still fairly mind-numbing travel though. Not really conducive to maintaining pace and tension - apart of course from the GMs tension with the players insisting their characters are spending every spare second cramming for skill points ;-)

Which is why I would favor micro-jumps in a house campaign (if not using reactionless drives) as players get bored easily. Climb out of the local gravity well to the top of the planet's Hill Sphere and then jump to the top of the target planets hill sphere. You still have to travel a fair distance at either end, perhaps 1% of an AU and maybe a day in total, but it's the exciting 1%.

[combatmedic]

Well, whatever the case: no reactionless real space drives in this universe.

Micro-jumps for rapid intra-system travel might work fine. I like that bit about climbing to the top of the Hill Sphere and then jumping to the next world. I might adapt something like this, if it's cool with you. Gravity dependent jump- you have to be on ''top'' of [or bottom of- no up or down in space] a planetary/stellar gravity well to initiate jump. If you misjump to deep space- good luck getting home. Instead of jump points, I could always say that the jump drives are limited in range, as in Traveller. That could help create trade routes. Factor in possible refueling/recharging needs, repair facilities, planetary economics,etc and I think I can still have the trade routes I want [no trade routes= no tramp steamers, no pirates,etc].

If I used something like that- jump would definitely not be instantaneous. If it were, travel might be too fast and easy.

[thtraveller]

Originally Posted by combatmedic

Well, whatever the case: no reactionless real space drives in this universe.

I like to keep the superscience to a minimum too. But realistic drives take too long to go anywhere. So using the one superscience device (the stardrive) in multiple but limited ways helps the speed of plot.

Micro-jumps for rapid intra-system travel might work fine. I like that bit about climbing to the top of the Hill Sphere and then jumping to the next world. I might adapt something like this, if it's cool with you.

Of course it's cool with me. It's something I have been pondering to mesh with SF tropes and typical plot speed but to wrap it up in plausible sounding science.

Gravity dependent jump- you have to be on ''top'' of [or bottom of- no up or down in space] a planetary/stellar gravity well to initiate jump.

Yes, I shouldn't really have said "top" as the "Hill" in Hill sphere is someones surname rather than a descriptive term - but it sort of alliterates.

If you misjump to deep space- good luck getting home. Instead of jump points, I could always say that the jump drives are limited in range, as in Traveller.

Yup. Maximum stable wormhole length or some such. You could perhaps say that both ends of a jump route had to be at some large mass or gravity well? Which makes routine travel easy, but "interesting" travel off the beaten track a challenge.

Remember you have to aim for your target star system where it is now, in 3 dimensional coordinates, rather than where you can currently see it with the light that left it several years ago. Star systems have typical relative velocities of 50-100kms to each other so they can have significantly moved laterally and away or towards you from their visual position. You are aiming for a microscopically small dot on a 3 dimensional sphere and getting the distance right too. It's easy to come up with limits on drive accuracy and astrogation limits over multiple parsecs.

However in-system jumps with a 2 parsec drive should be simple. Though if required there might be a minimum jump length based on the cycle time of the drive. If you can say jump 1 parsec (200,000 AU) in 20 hours, then jump time for the 2 AU to Mars is under a second.

That could help create trade routes. Factor in possible refueling/recharging needs, repair facilities, planetary economics,etc and I think I can still have the trade routes I want [no trade routes= no tramp steamers, no pirates,etc].

If I used something like that- jump would definitely not be instantaneous. If it were, travel might be too fast and easy.

Sounds good to me, though personally I always felt the Traveller 7 day jump was too long (and too conveniently matched Earth units). Many hours to a small number of days just "feels right" IMO.

Aside: Another idea I have been toying with (to encourage a small ship universe) is making jump speed dependent on ship mass. So a 1000 ton ship might make a 1 parsec journey in 33 hours and a 2000 ton ship in 66 hours. With the fuzzy lower mass limit for jump (whatever that is for your universe) being the size used for express courier ships with highly tuned drives on precise routes. Then next size up your free traders and frontier scouts.