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Old 10-16-2021, 05:23 AM   #1
scc
 
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Default Help With Hyperspace!

So to deal with a brain worm I need some help coming up with new formula's for Vehicles for Hypderdrives, Reactionless Thrusters, Artificial Gravity, and maybe some other things. Please note that what I need help with isn't advanced enough to be called an idea, it's more of a vision, that of a single early Starfighter and a small carrier that carries it, coupled with some ideas I've had for a Sci-Fi/Space setting for a while, and please send help because the side of me that likes to tinker wants to design these two ships with Vehicles with a side order of Mecha for weapons.

Now as I'm going to be building this in Vehicles I need to spend a moment talking about Tech Levels, Vehicles, being a 3rd Ed book, uses that editions TL's, which place things about one TL lower, and I'm going to be using 3rd Ed. TL's for the rest of this post, so in your head add 1 to any TL's mentioned from here on. For example Lasers are TL8 in 3rd Ed. but TL9 currently.

So, yeah the rules, such as they are, for what I'm wanting to do. Reactionless drives exist and their subject to the Boost Drive rules sort-of, maybe. Yeah, because that makes sense. Starting this is hard, but for tactical combat a Reactionless drive has a top speed, something like 30 seconds of acceleration, because that's the way they seem to work in fiction, yes break the laws of physics, but Reactionless drives do that anyway, so it's not really a big problem to do it to make craft using them act like space fighters. That's for tactical drives. Transit drives are either Reactionless drives switched to a mode that allows for a much higher, or unlimited, top speed, but at the cost of acceleration, or normal reaction drives are used for transiting. It's quite possible that it's a two stage thing, reaction drives at first, switching to reactionless once they're figured out better.

So my thoughts are the TL10 Super-Thruster @ TL8, the TL11 Standard Thruster @ TL9 and then then TL11 Super-Thruster @ TL10, with a revised cost. And that should be enough for the short term. This is why I make these sorts of posts, they help me work things out. Powering this is a problem, looks like I'll need MHD turbines or power banks, at least for tactical combat early on, which is an interesting complication. And also answers the question transit drives, they're reaction, at least early on.

Artificial Gravity, Vehicles says it's TL10, but it's also superscience, so if I want it at TL8, it's at TL8. That said, what does it cost to add it to a ship at that level? Do I just use the stock TL10 costs or do I increase them or something else entirely, let me know!

So last, Hyperdrives, the hardest one to do. The system I'm going for most closely resembles Babylon 5 with a side order of Dune or BattleTech. There are two pieces of equipment that are related to hyperspace travel, the Hyperdrive, which keeps you in Hyperspace, and is mounted on vessels the size of modern cruisers; and the Hypermotivator, which allows you to access Hyperspace and is the size of a cruiser. Early on Hypermotivators can only be found in B5 style Jumpgates, which are still important later on simply because Jumpgates allow for faster travel. For the Hyperdrives I'll probably use existing Hyperdrives costs and size, but for Hypermotivators, well there are at least two factors that control them, the max tonnage that can pass through them and their speed factor, this speed factor is important because this cubed is how much faster vessel that used it is faster then it would be in real space, and it squared should probably be part of the equation, so this is where I really need help, any suggestions for how big one of these should be?
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Old 10-16-2021, 09:23 AM   #2
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Default Re: Help With Hyperspace!

Your hyperdrive size problem & other issues could be easily solved by building your ships with GURPS Spaceships. Have you considered using that?

I've used the Spaceships books to design spaceships, age of sail ships, Zepplins (as mother-ships for for fighters) & other types )including as a flying base for my DF Artificer & his party). It's a very versatile & simple system.
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Old 10-16-2021, 10:23 AM   #3
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Default Re: Help With Hyperspace!

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Originally Posted by scc View Post
this speed factor is important because this cubed is how much faster vessel that used it is faster then it would be in real space
How much space is your game going to cover? That is, how much of our galaxy? How long should it take to get from one "close" planet to another -- and how far apart are those habitable planets? Any particular famous spots that you want to include in the area reachable by ships? Those decisions affect how fast your hyperdrive needs to be. A formula comes second; you pick that (if you want one at all) to suit your game's story.

Star Trek: TOS used the cubic formula. It sounded good. But if you do the math, it means that the Enterprise doing warp 6 (warp 8 was emergencies only) would only being doing 216c, which in turn means on that 5-year mission, it could travel a total of about 1000 light years, if it did nothing but travel (as opposed to hanging around in orbit having adventures). If Kirk went only one place (instead of around 70) and came back, that one place would be at most 500 ly away. In other words, a pretty small region of the galaxy. And even that's assuming a real-space speed of 1.0 c. Your setting has a top speed, presumably some relatively small fraction of that value, so that much smaller of a region to play in.

So before picking a formula that calculates hyper-speed from real-space-speed, decide how much you want to reach. Galaxy-spanning empires? Small cozy corners where you can concentrate on details of a few planets? It's first and foremost a narrative question. Formulae and technobabble come second -- as you say, we're already breaking the laws of physics just to have the game at all, so there's no point in getting hung up on trying to cling to any particular rule just because it feels mathematical.

(ST:TNG changed to the scale to warp 10 being infinitely fast, warp numbers asymptotically approaching 10 based on a hand-drawn sketch of a curve with no formula, just something that seemed like it would kind of work without being too terribly different from previous shows on the low end. Worked fine as far as the show was concerned. Made no noticeable difference in practice IMO, because Trek was never really concerned with exactly how far apart two different planets were in the first place. Travel time is a plot point -- can Starfleet intervene, or are the PCs out there on their own? Can you actually ship medicine to a planet before the plague runs its course anyway? Are the invading bad guys going to reach Earth before you can build another fleet to stop them after they wiped the first one? That's travel time versus build speed... so you also care about whether it's guys in EVA suits with space welders, or nanofacs 3D printing more ships as fast as the guide/power lasers can scan.)
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Old 10-17-2021, 04:32 AM   #4
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Default Re: Help With Hyperspace!

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Originally Posted by Anaraxes View Post
How much space is your game going to cover? That is, how much of our galaxy? How long should it take to get from one "close" planet to another -- and how far apart are those habitable planets? Any particular famous spots that you want to include in the area reachable by ships? Those decisions affect how fast your hyperdrive needs to be. A formula comes second; you pick that (if you want one at all) to suit your game's story.

Star Trek: TOS used the cubic formula. It sounded good. But if you do the math, it means that the Enterprise doing warp 6 (warp 8 was emergencies only) would only being doing 216c, which in turn means on that 5-year mission, it could travel a total of about 1000 light years, if it did nothing but travel (as opposed to hanging around in orbit having adventures). If Kirk went only one place (instead of around 70) and came back, that one place would be at most 500 ly away. In other words, a pretty small region of the galaxy. And even that's assuming a real-space speed of 1.0 c. Your setting has a top speed, presumably some relatively small fraction of that value, so that much smaller of a region to play in.

So before picking a formula that calculates hyper-speed from real-space-speed, decide how much you want to reach. Galaxy-spanning empires? Small cozy corners where you can concentrate on details of a few planets? It's first and foremost a narrative question. Formulae and technobabble come second -- as you say, we're already breaking the laws of physics just to have the game at all, so there's no point in getting hung up on trying to cling to any particular rule just because it feels mathematical.
So this isn't really an idea, it's more of a germ of an idea, but ST sized, as in the 150 member planets that the Federation has as of TNG, actually feels about right. That said this isn't the sort of setting where PC's will have access to their own ships.

Beyond that travel times will vary by time, what your ship is equipped with and even location, after all Jumpgates are much faster then your own hypermotivator, so making a detour to get to a faster Jumpgate might be worth it. For hard numbers the initial exploration of nearby stars uses and 20 rating motivator and later ears might have up to 50 rating, allowing short trips to nearby starts in a few months.
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Old 10-17-2021, 10:39 AM   #5
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So. For hard numbers the initial exploration of nearby stars uses and 20 rating motivator and later ears might have up to 50 rating, allowing short trips to nearby starts in a few months.
I went back and checked but you haven't explained (in this thread at least) what those "ratings" mean. All i get is the idea that in the current/advanced state of things it takes no less than several months to get to the near stars.

With those speeds you could see large scale colonization but there will be little trade or other activities. Hyperspace speed might not matter much to your PCs if the general speed range is "Too Slow".
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Old 10-17-2021, 04:05 PM   #6
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I went back and checked but you haven't explained (in this thread at least) what those "ratings" mean. All i get is the idea that in the current/advanced state of things it takes no less than several months to get to the near stars.
Ah, sorry I used speed factor in my OP, didn't I? Well whatever I call it, the Hyperspace Goodness Thing cubed is how much faster you go in hyperspace.

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Originally Posted by Fred Brackin View Post
With those speeds you could see large scale colonization but there will be little trade or other activities. Hyperspace speed might not matter much to your PCs if the general speed range is "Too Slow".
Only if you compare it to modern air travel, and honestly giving FTL travel times comparable to modern air travel is only going to end weirdly, like it taking less time to travel half-way across the galaxy then it takes to travel halfway around a planet in a plane.
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Old 10-17-2021, 07:42 PM   #7
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Default Re: Help With Hyperspace!

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Ah, sorry I used speed factor in my OP, didn't I? Well whatever I call it, the Hyperspace Goodness Thing cubed is how much faster you go in hyperspace.

.
No, I jsut checked again and in your initial post in this thread you did not explain "speed factors". "How much faster you go in hyperspace" is kind of vague as well.

If it's a multiple of lightspeed then dividing 4.3 light-years by 20 get's you c. 80 days to Alpha Centauri but Alpha C. is a _lot_ closer than the next vague possibility. ISTR 7 of those in the nearest 40 light-years.

The last time we thrashed out what was known we came up with an average distance of 200 light-years between Earth-like planets and if you have 150 of thsoe you will be at that number (on average of course).

Dividing 200 light-years by 50 and you get 4 years travel time (10 years at your factor 20). If that's your highest speed over that distance you're going to see one-way travel and quite possibly in hibernation mode to avoid wasting the time in transit.
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Old 10-17-2021, 11:24 PM   #8
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Default Re: Help With Hyperspace!

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Originally Posted by scc View Post
Ah, sorry I used speed factor in my OP, didn't I? Well whatever I call it, the Hyperspace Goodness Thing cubed is how much faster you go in hyperspace.
So, basically you're saying that the hyperspace factor cubed is how much "smaller" the hyperspace universe is than the real-space universe, right? So, relative velocities are multiplied by the hyperspace factor the hyperspace factor the hyperspace factor. Am I reading that right?
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Old 10-18-2021, 01:02 AM   #9
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Originally Posted by Fred Brackin View Post
No, I jsut checked again and in your initial post in this thread you did not explain "speed factors". "How much faster you go in hyperspace" is kind of vague as well.

If it's a multiple of lightspeed then dividing 4.3 light-years by 20 get's you c. 80 days to Alpha Centauri but Alpha C. is a _lot_ closer than the next vague possibility. ISTR 7 of those in the nearest 40 light-years.

The last time we thrashed out what was known we came up with an average distance of 200 light-years between Earth-like planets and if you have 150 of thsoe you will be at that number (on average of course).

Dividing 200 light-years by 50 and you get 4 years travel time (10 years at your factor 20). If that's your highest speed over that distance you're going to see one-way travel and quite possibly in hibernation mode to avoid wasting the time in transit.
No, I give decent details, if not very clearly, in my OP:

Quote:
Originally Posted by scc View Post
this speed factor is important because this cubed is how much faster vessel that used it is faster then it would be in real space
Now this could be clearer still I realize upon reflection, so let me clarify that: Going through a portal to hyperspace takes you to a dimension that is physically smaller then ours by speed factor cubed, but has point-to-point corispondence, this last means you can still accelerate once in hyperspace (So technically there are many different hyperspace's, like a layer cake and going higher up makes you faster).

What I didn't mention is how fast ships can yet up to, well that's 36Kps at TL8 and 180Kps at TL9 due to improved drives technology.
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Old 10-18-2021, 08:28 AM   #10
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Default Re: Help With Hyperspace!

So we're looking at a 625,000 multiplier for a speed 50 gate, which is considered to be a really good gate. At 180 kps the time for a single light year is



1 Ly * 9.46e12 km/LY / 6.25e5 / 1.8e2 km/sec / 3.6e3 sec/hour= 23.4 hours


So a day per light year with the really fancy portals. That's a little slow, but its close enough to feel intentional, and suggests you already did your math.
If that's what you want to run your setting at, it could very well work. It also depends on how close your systems are to each other.



To answer your question about ideal weight for a hyper-motivator, I have to ask what your goals are. Are the largest hypergates supposed limited by technology or by expense? Do you need a receiving gate to pop out of hyperspace again, motivating everything to be the same size, or can I build an enormous factor 234 gate around Jupiter to maintain and leverage solar economic dominance? Should "slow" gates be cheap but fast ones more expensive? Is there an ideal size you want to push ships towards?
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