Extended Jumps

[Ran Targas]

I'm trying to create a more Alien style TU with more expansive territories, greater distance between settlements, and cold berthing being the common method of travel. So my question for the forum is "Has anyone recently toyed with having the jump drive limit only how fast you can travel a parsec rather than the max range of a jump?"

For example; my J-1 drive can continuously putter along at 1 parsec/week as long as I have consumables to maintain habitability. After 52 weeks, I've gone 52 parsecs without coming out of jump space. My J-2 drive can cover the same distance in just 26 weeks, as would be expected. But there is no need to refuel every parsec, you'd just keep drifting until the drive turns off or stops working.

Not that this notion isn't fraught for abuse but there could also be significant drawbacks applied such as a) jumps can only be straight lines and b) can only pass through empty squares (i.e. More sensitive to mass), and c) the longer in jump, the more the course drifts, or other rules that would make sense for prolonged interdimensional travel.

Please reply with any ideas for limitations other than what I've listed or odds of having problems if you like.

 

[Quint]

I've toyed with similar ideas as well over the years. One mechanic that also works well is making the Astrogation check increase in difficulty the longer the jump and/or due to the number of obstacles in the way. That's a nice limiter on how long jumps actually end up being.

D.

 

[Supplement Four]

You may be interested in the links in THIS POST.

Especially, THIS THREAD.





From that thread...

From what I understand of the rule in the Aliens rpg, the jump happens quick--in hours or a single day. And, the Jump taken is equal to the Jump # multiplied by 5 light years.

The time taken is the week required to retune and recharge the jump drive.

So, a J-2 ship would jump 10 light years in a day, spend a week recharging, jump another 10 ly, another week recharging, over and over.

If you've got to travel 100 light years, then you're talking about a journey of 10 weeks.

I think you could easily use the Traveller world and system generation system, as-is. No changes required. Plot out the systems on a hex map as usual, but, really, only one ones that you're interested in are the worlds with Atmosphere Types 6, 7, or 8. If you look at the Spinward Marches, for example, then remove populations from all worlds that aren't Atmo 6-8, you'll thin out the number of available worlds considerably, leaving the rest of space populated by planets that are not kind to human colonization. You'll throw in a few worlds with Atmo other than 6-8, here and there, to spice up things, but remember how expensive it is to colonize worlds that aren't conducive to human existence.



You'll probably find THIS helpful.

 

[Supplement Four]

One mechanic that also works well is making the Astrogation check increase in difficulty the longer the jump and/or due to the number of obstacles in the way.

What about using the outcome of a Navigation check to establish the limit of the next jump? This would all be pre-rolled by the player, plotting course on a hex map, before the jump was made. This is the work of "inputting the Nav coordinates". Then, everybody goes into the berths. Sleepy, sleepy. As the ship's computer guides everyone.

If Prometheus is, indeed, a prequel, then using synthetics to safeguard the crew while they are in cold sleep is a possibility, too. Book 8, Robots.



What I'm thinking is, the higher the Nav roll, then the longer the ship will stay in Jump space without a correction. Each correction involves the ship exiting Jump space, re-calibrating, then re-entering J-Space. The total length of the trip will be shorter if a Navigator can decrease the number of times the ship has to correct during the passage.

 

[Spinward Scout]

One of the things that was mentioned with T20 (or maybe it was a carryover from another version) was that the higher the Tech Level, the more Jumps you could get from the same amount of fuel. Say, at TL-9, a J-1 used 20 tons of fuel, at TL-10, a J-1 might only need 10 tons, at TL-11, only 5 tons, and so on... Then you've got extra fuel to make more Jumps before refueling.

Then, at TL-Whatever, it might take 3 Jumps to get to Zeta Reticulae, but that's 3 consecutive Jumps without any major stopover - only stopping long enough to calculate a new Jump. Which is almost the same as staying in JumpSpace the whole time.

 

[Vladika]

After 52 weeks, I've gone 52 parsecs without coming out of jump space.

Um, FUEL?

 

[Supplement Four]

Um, FUEL?

Obviously different in the Alien universe, and he's got to go that way if he's going to make the type of jumps he wants. Fuel can't be an issue like it is in a normal Traveller game.

 

[mike wightman]

Different universe, different ftl technology and different fuel use.

You can do all sorts of stuff just with LBB2 drives.

Scrap fuel altogether, designate jump fuel % as reaction mass for the manoeuvre drive, switch the manoeuvre drive mass with jump drive mass etc.

Recombine them in any way you want to produce the in universe effects you want.

Only major question is this - is there a ftl comm system that operates like radio or does communication move at the speed of ships?

 

[Supplement Four]

Only major question is this - is there a ftl comm system that operates like radio or does communication move at the speed of ships?

My impression is that communication is ftl, but still a bit slow, taking days for a message to be received. In Aliens, this was the feeling I got when the Company dude said that communication had been lost with the Colony. And, in Alien 3, it seems also that communication took some time to reach Earth or what ever facility sent the Company ship at the end.

 

[mike wightman]

So faster than ships but not instant.

 

[Supplement Four]

So faster than ships but not instant.

That's my impression, Sigg. I've read several Alien universe novels and comics, but I haven't read too much of the game detail or any of the books that describe the universe. I'm sure there's info about it on the net someplace.

 

[Supplement Four]

This is a quote from a forum discussing communication speed in the Alien universe...

I was talking about this in another thread. I believe that there is faster than light travel in the Alien universe. This is implied in Aliens the Director's Cut (Ripley has a daughter that she leaves behind and is shocked to find that 57 years have passed while she is adrift in the shuttle). I believe that FTL travel in sci fi cheats special relativity and time dilation, making the time they experience on their trip the same time that passes on earth.

However, they don't seem to have 'subspace' communication capabilities. Or they do, but the communication signals cannot go any faster than their ship. In Alien they cannot communicate directly with WY, so they use Mother with her preprogrammed protocools and instructions as a substitute. Alien 3, however, seems to be the exception and the characters do appear to use some sort of faster than light subspace communication technology.
As for Prometheus, nothing in film indicates either way whether or not they are traveling faster than light. Ridley does mention time dilation in the commentary and Weyland does say that he's long dead (although this could just be referring to the 2 years that have passed on the Prometheus, as well as the 2 years that have passed on earth/mars if the Prometheus is travelling faster than light). And as far as how far LV-223 is supposed to be from earth, well if they can't travel faster than light, it's got to be within 2 lights years away (and I'm sure that it's not, so this would indicate FTL travel, and again, I like to think that FLT travel cheats special relativity and time dilation). ((EDIT: Yeah, I realize I'm being dumb here, with the help of javablue, I go on to argue with myself))
Planet of the Apes, by the way, is the only film that I know of that addresses time dilation. I'm actually watching it tonight at my library's weekly classic sci fi film night!

The rest of the discussion is HERE.

 

[aramis]

One of the things that was mentioned with T20 (or maybe it was a carryover from another version) was that the higher the Tech Level, the more Jumps you could get from the same amount of fuel. Say, at TL-9, a J-1 used 20 tons of fuel, at TL-10, a J-1 might only need 10 tons, at TL-11, only 5 tons, and so on... Then you've got extra fuel to make more Jumps before refueling.

Actually, thats from MegaTraveller, not T20.

Also note: if you use the fuel required per jump unit, rather than the text's 10% per Jn, you get the MT fuel rates of 5x JDrive size.

 

[epicenter00]

Please reply with any ideas for limitations other than what I've listed or odds of having problems if you like.

Interstellar war becomes a very interesting issue with drives like the ones you're describing. You wouldn't really know some nation/empire/corporation was going to go to war with you until their war fleet shows up in orbit around your capital. After all, political tensions might be high, but your opponents could stagger their jump times of their ships. In an extreme example, it would be possible to jump five warships from twenty different worlds at different times - it would take some coordination, but you could have ships of different jump speeds converge on the same point so that 100 warships emerge from jump around your homeworld at the same time.

A possible solution might be some sort of sensor that can detect starships "in jump" even if they're some parsecs distant and can do it at a speed faster than jump (of course, this technology might also result in FTL communications which are not instant, but still faster than any ship can move).

 

[Carlobrand]

Unless there's a way to intercept the ships in flight, you've got a universe without defensible borders. The enemy can concentrate his force at any point within your territory and there is not a thing you can do to stop it; best you can hope for is to concentrate more force at the same point before he gets there. If you can't do that, he defeats you in detail, one world at a time - most likely while you're doing the same to his worlds.

And, detecting 100 inbound ships is of little benefit if you can't summon help in time to deal with them. The ships show up, wreck things, and they're on their way before your support arrives.

 

[Ran Targas]

The intent wasn't to replicate the 3I using a different jump paradigm; my goal is to create a different kind of universe where there's a lot more space to get lost in. Humans will still think they're alone and don't live under the fear of organized military conquest. Their settlements are few and very far between and travelers spend years in cold berths, outliving their contemporaries by decades.

 

[robject]

So faster than ships but not instant.

"At the speed of Plot", to paraphrase J. Michael Straczynsky.

 

[aramis]

The intent wasn't to replicate the 3I using a different jump paradigm; my goal is to create a different kind of universe where there's a lot more space to get lost in. Humans will still think they're alone and don't live under the fear of organized military conquest. Their settlements are few and very far between and travelers spend years in cold berths, outliving their contemporaries by decades.

I've done it as a form of Warp Drive, but not setting exclusive. It doesn't break much if you can go FTL, but can still only send information at speed of ship.

 

[Carlobrand]

I'm trying to create a more Alien style TU with more expansive territories, greater distance between settlements, and cold berthing being the common method of travel. ... my J-1 drive can continuously putter along at 1 parsec/week as long as I have consumables to maintain habitability. After 52 weeks, I've gone 52 parsecs without coming out of jump space. My J-2 drive can cover the same distance in just 26 weeks, as would be expected. But there is no need to refuel every parsec, you'd just keep drifting until the drive turns off or stops working. ...

The intent wasn't to replicate the 3I using a different jump paradigm; my goal is to create a different kind of universe where there's a lot more space to get lost in. Humans will still think they're alone and don't live under the fear of organized military conquest. Their settlements are few and very far between and travelers spend years in cold berths, outliving their contemporaries by decades.

Stellar density and speed are in conflict. You need additional limiting assumptions. Unless you invent some reason not to, there's absolutely no reason people can't settle vacuum worlds and other such inhospitable locales in nearby systems, pursuing whatever interesting minerals might be found in such places. Given your speeds, that undermines your settlements-few-and-far-between model. If we undermine the settlements-few-and-far-between model, then military pressure from the homeworld or other major population centers becomes a problem again. Ergo, you need to slow things down a lot so the homeworld is not tempted to go make demands on the colonies - or at least so it's too time-consuming and expensive to make a habit of it - or you need to find some reason why people are not settling all those lovely systems between A and B. Without that, we're back to 100 ships showing up whenever and wherever they desire to impose their will on the people beneath them.

One thought is ships that don't exceed light speed. You have a way to get close to light speed and to come down from that, but you can't actually exceed C. Your travelers spend the trip in cold sleep because it takes a few years to get to the nearest stars.

Another is low tech: say your tech isn't up to maintaining an artificial environment indefinitely. You can recycle air, you can recycle water, but growing food is proving more complicated. Your best efforts can keep a closed cycle going for a few months or years, but it always breaks down eventually despite the closest attention. You are constrained to search out earthlike worlds, and there aren't many of those, and your stays on non-earthlike worlds are limited by the need to periodically completely rebuild the food plant - and the risk that you could run out of rations before the ship with the replacement food plant equipment finally arrives. It's a good deal grittier than our comfy TL15 Imperium.

That last implies a TL9 or so setting, maybe TL11 if you're eager for the military to have a speed edge over civilians, but it's harder to argue a TL11 society can't manage a stable closed food cycle. On the other hand, you could just toss out Book-5 drive tech level rules: you could build a TL9 society with star drives that pretty much do whatever you decide they can do.

 

[tim_manley]

my J-1 drive can continuously putter along at 1 parsec/week as long as I have consumables to maintain habitability. After 52 weeks, I've gone 52 parsecs without coming out of jump space. My J-2 drive can cover the same distance in just 26 weeks, as would be expected. But there is no need to refuel every parsec, you'd just keep drifting until the drive turns off or stops working.

You change the dynamic of how important systems are to space travel. The urgency to secure Gas Giants or choke points is gone. Borders are malleable. An enemy fleet that is 45 parsecs away can send their flotilla of J1 battleships to attack your capital all by staying in jump space for 45 weeks.