[Spaceships] Designing Hyperspace / FTL for space opera (and implications)

[David Johnston2]

Originally Posted by Molokh

That's somewhat sad, as this essentially means that TL(x)^ > TL(x). It makes building a world where many technological solutions coexist in different niches much more difficult, because items of the same absolute TL no longer balance against each other.

Remember super-science doesn't really have a tech level. All TL(x)^ suggestions are just that, suggestions based on the kind of props that a certain kind of super-science tends to be associated. In The Road Not Taken, anti-gravity is a TL 2^ development and FTL travel is a TL 3^. One suggested alternative is to only introduce them at TL 13+. The only reason why certain super-science developments are suggested for certain TLs is because they usually fit with the matching realistic props and to keep them in intuitive perspective with each other. But yes, not being bounded by plausibility is better than being bounded by plausibility in terms of the bang you get for your buck.

[nerdvana]

I have always liked the Stutterwarp FTL method from 2300AD (for details on it you can read these two articles: "Stutterwarp Technology in 2300" by Rob Caswell and Timothy B. Brown and "Stutterwarp Revisited" by Lester W. Smith). The only problem I have found with it is that it doesn't allow for relatively safe transit though the oort cloud. I am considering adding sensors that would allow for the sensing of objects while flying at FTL speeds, but that is counter the original method which I like (the fact that there are no FTL sensors is a great feature IMO).

[nerdvana]

Originally Posted by mike wightman @the Citizens of the Imperium Forum

The Oort cloud - if it exists - would be so low density I wouldn't think they worry about it.

Depending on the trafic in a system youd be more likely to run into another ship.

I got the above answer on the above mentioned forum. Its a satisfactory answer for me. :)

[vicky_molokh]

BTW, there's also the consideration of Star Fuel. Whether it is needed at all, for the whole journey, or just for the start and end (e.g. hyperspace entry/exit). And the price is an issue too.

[Timolas]

Completely agree with your thoughts on jump points / jump gates, Molokh - they might be great for giving a universe choke points for a strategy type game. For your average band of piratical pc space opera reprobates however, they make travel very restrictive.

I also think it makes the journey a little boring if interstellar flight is reduced to out-to-the-jump-point, in-from-the-jump-point all the time. Plus there is something a little mundane to my ears about the phrase "interstellar subway system" as wormhole / jumpgate / point-to-point jump drive maps invariably get described. Do they come with graffiti and restrooms you'd only dare venture into with a flamethrower..?

As you say, hyperdrive has a lot going for it, and there is great fun to be had in the fiddly details; one variant I like is if the hyperspace entry condition is a velocity vector rather than a location - gives a whole new range of options and constraints.

But hyperdrive leaves you with the thorny problem of your maneuver drive system - dramatically interesting space drives are WMDs, simple as that... Or they are a whole other strand of superscience in addition to your stardrive.

So I've actually gone down the warp drive route for my space opera campaign, liberally stealing ideas from 2300AD's stutterwarp and the Humanx KK drive (that's a posigrav drive to all you AAnn out there...). One of my guiding principles was that I didn't want planetary travel to be greatly affected by starship technology - I like the idea of tanks and air cushion vehicles and tilt rotors in my sci-fi; and cheap reactionless drives or contragravity threaten that.

My "gravity drive" therefore can only operate in vacuum - in atmo it starts ingesting matter rapidly until it overheats and, um, explodes. It will however work perfectly in low orbit (this helps orbital access using realistic reaction drives - ships only need to boost on a sub-orbital arc to get out of the atmosphere, before activating the gravity drive - slashing the delta v requirement).

The drive itself is a form of pseudovelocity, but not completely: it allows some degree of momentum exchange with a planetary mass when nearby (1G per stardrive system in Spaceships terms) - good for orbital maneuvers and tidying up your vectors from one planet to the next, and technically not reactionless (the reaction mass is the planet itself). This "momentum coupling" drops off pretty rapidly as you gain altitude, so it wouldn't be of use in conventional space travel other than for insertion into a Hohmann orbit or similar.

At the same time however, as you gain altitude, the drive's space-time warp effect also gains in strength. Of limited use close to a planet, beyond a certain distance it increases your pseudovelocity such that you are now relocating yourself at your stardrive rating in AU per hour. And then even further out again, as you leave the system, the warp effect increases to be equal to stardrive rating in lightyears per day. (Discrete changes in speed like this are for gameability: ideally it'd be a gradual change - the flatter the local spacetime, the faster you go)

There are no long range FTL comms in my setting, but the space warp effect of a working gravity drive can be detected in real time up to a lightyear or so away - so FTL ships are not invisible.

What all this handwavium buys me is a limited superscience (just the gravity drive) setting with a lot of bang for its buck. Did I mention that the drive gives you artificial gravity for free...? ;-) The main implications are:

1) Low orbit is one of rocketry and fairly conventional spaceships type stuff.

2) Interplanetary travel is fast, and where the big space opera dogfights happen, with ships weaving in and around one another at significant fractions of c.

3) Out in interstellar space, the vast distances and detection range means that even though starships are now warping at hundreds of times the speed of light, the actual feel is more like submarine warfare (did you hear the one about how ASW means "awfully slow warfare"? ;-D). Starships crawl across the expanse, crews peering intently at their detector screens, trying to make sense of the ultrawave static around them. Interstellar borders apply, and ships can be pursued across the void. Jumping to lightspeed is not an instant getaway - so operating outside the law takes stealth and cunning. In a pinch you could always drop out of warp and go quiet, hoping the bad guys hadn't got a clear enough fix on you to still find you....

And that's about it. I spent months and months toying with different technical architectures, and this is the one I settled on as giving (hopefully) the most variety and possibility for adventure.

That's not to say you couldn't achieve all that with a hyperdrive of course.... And in hyperspace, as per David Brin's E level thing in Uplift, you also get the chance of weird and wacky fantasy environments to play with. Hyperspace can (and should) be anything you can dream up.

Sigh, I dunno. So many cool things to play with, so few hours at the gaming table....!

[cmdicely]

Originally Posted by Molokh

That's somewhat sad, as this essentially means that TL(x)^ > TL(x).

The nature of superscience makes it so that its more than that: its often the case that, for a given application, TL(x)^ > TL(y) for all combinations of x and y.

It makes building a world where many technological solutions coexist in different niches much more difficult, because items of the same absolute TL no longer balance against each other.

Every combination of a basic TL plus specific superscience inclusions is, effectively, its own TL that is not "the same absolute TL" as any other such combination.

And, yes, the inclusion of superscience in a particular area often renders irrelevant non-superscience technologies of the same type.

[nerdvana]

Timolas, that is brilliant. I've been trying to develop something similar. Do you mind if I use it wholesale for my game? (Credit given, naturally.)

[Timolas]

Be my guest, nerdvana! No credit required, natch - it's all just an amalgam of other people's ideas after all.

Pretty high on that list has to be Alan Dean Foster of course : I think his KK drive rocks. Hey everyone! How about some love for ADF and Humanx, eh? :-) In case you don't know it; the KK drive projects a super-high-strength artificial gravity field ahead of the ship, curving the continuum and drawing the ship towards it. As the ship gets faster and faster, this distortion effect ultimately rips a hole into "space-plus", which is either some form of hyperspace, or simply a tachyonic view of our own universe. I'm not quite sure which; as much as I enjoy Mr Foster's work, he's not amazingly consistent in his descriptions of this stuff from one book to the next. Sheesh I dunno. Anyone might start getting the impression that authors don't think the minutiae of how superscience works is Important! ;-D

An intriguing quality to the KK drive (that made me think "hmm that'll have to go" when I got to roleplayingise the concept) is that the gravity field is SO strong that if you're not careful you can change the orbits of planets in a star system, just by careless navigation. Close to a planet the KK drive has to be run at a tiny fraction of its full power else it causes tsunami and earthquakes galore. Makes the normal SF GM's concerns about fusion drive flamethrowers and relativistic kill vehicles rather irrelevant, no? Or to put that another way: ouch time.

Uh oh - I think I may have just quoted Jar Jar Binks. Clearly time to post this and slink quietly away.

Still I'd like to see someone trump one of those "Who'd win in a fight between Star Wars, Star Trek, BSG and Babylon 5?" type debates with this. "Yeah??? Well the Humanx Commonwealth would wipe out all your planets through the power of bad parking. Mwa ha ha."

[SCAR]

Originally Posted by Timolas

Still I'd like to see someone trump one of those "Who'd win in a fight between Star Wars, Star Trek, BSG and Babylon 5?" type debates with this. "Yeah??? Well the Humanx Commonwealth would wipe out all your planets through the power of bad parking. Mwa ha ha."

If I'm remembering correctly, the Slipstream Drive from Andromeda can also cause major tectonic activity if used too close to a planet, and in one episode, they actually do use the drive near a planet to save it from being totally destroyed by singularity bombs, by sucking the bombs into slipstream! (something like that!)

I think you 'bad parking' quote wins by itself though!

[Fred Brackin]

Originally Posted by Timolas

I also think it makes the journey a little boring if interstellar flight is reduced to out-to-the-jump-point, in-from-the-jump-point all the time.

You can solve this by requiring multiple jumps.

The drive I used in my last 2 Space campaigns used jump _lines_. These stretched between stars within a critical factor of each other (which just so happened to work out to distance in parsecs equal to 3x their combined masses where Sol equals 1). Big stars equal long jumplines. Small stars make for short lines except when the line connects to a big star.

This greatly simplified the stellar map. You could ignore almost all the M-class Dwarfs and since binary stars tended to cross their own jumplines and render them unstable you could ignore those too.

This left you with some Ks, Most Gs, almost all Fs and virtually all As connected to one or more additional stars with most As connected to each other. Stars larger than Class A are too rare to be placed on a star-map randomly.

However, the frequency of inhabitable worlds was such that it usually took 3-5 jumps to travel between then in a sort of zig-zag pattern.

The stars between inhabitable worlds were almost always wilderness and potential places for pirate encounters.

On the first and last legs of the journey you got on and off the jumplines wherever was closest to your target planet but in the middle passages you rode the line as close to the star as you dared to minimize transit time to the next jumpline.

The limit was around 0.1 AUs for Sol and that area was called "the hot zone". The corona would interfere with most sensors and it was easier to hide IR signatures as well so it was again a friendly environment for pirates.

On very long trips you tended to head to the nearest Class A star and use its' long jumplines, frequently leading to another A. this was called "Taking the A Train".

I used psuedovelocity to travel to and from jumplines with only enough time spent on the jumpline to hear a whooshing noize. Average trip time was around a week and most ships carried enough fuel for 2 weeks.

It worked out quite well. Piracy was possible. mining or squatting on top of a single jump _point_ was not and most systems had more than one way in or out.