How could you travel to other solar systems in KSP without unrealistic FTL?

[kerbonaut101]

If other solar systems are eventually added into KSP I would hope that the realism would be retained and Squad wont take KSP into the realm of Sci-Fi-impossible-in-real-life technology. So I started this thread to try and brainstorm some ideas on how they could manage interstellar travel (obviously the first thing they'd need is 1 billion, 1 trillion, 1 quadrillion time acceleration ect...)

I would rather see some of these concepts implemented...

http://en.wikipedia.org/wiki/Interstellar_travel#Propulsion

The Acculbierre drive might also be a good candidate

http://en.wikipedia.org/wiki/Alcubierre_drive

As long as it's based on real science then im happy with it

[Rusty6899]

One problem with this is that even if you could perform x10¹² time acceleration, most of that time would need to be spent actually accelerating. So you would have to be able to control your burns through that length of time. Also, If you were in career mode, a mission to another Solar System could take decades (optimistically) so you would either have to time accelerate to complete the mission (neglecting your space program for years at a time) or start a mission and wait for 10... 20... 30 game years to pass to complete it.

Another problem is that an entire galaxy would probably need to be created to facilitate interstellar travel as there would have to be an SOI in interstellar space. I suppose it may be possible to have a very small galaxy, with 20+ stars orbiting a massive black hole, but such an empty galaxy wouldn't be very immersive.

I would say that the Alcubierre drive would be exactly "unrealistic FTL" as there is no scientific basis for claiming that it would actually work. You might as well be able to discover wormholes in the tracking station.

Another option may be to have Kerbol as part of a binary or multiple star system although I am not entirely sure of how travel between the planets could be modelled in that situation.

I think the devs are reluctant to include relativity into KSP anyway so I think that any interstellar travel would need to be done through conventional rockets. I doubt the devs will include interplanetary travel unless a mod is made that overcomes the challenges associated with it first and it would definitely divide opinion if it were released.

[Aghanim]

Warp drive is FTL, don't know if realistic of not but its already implemented in KSPI, and balanced. The thing is that we doesn't have real other solar system yet

[tychochallenge]

there are mods that add other solar systems to the game using krag's planet factory creators edition, but unfortunately, most of them are unrealistically close, some are closer than Eeloo:huh:. In KSP, there is no limit to the sun's SOI. First, there should be a SOI for the sun/boundary between sun's SOI and interstellar space(heliopause). After all the other features are added to the game, the devs could just give each new star its own SOI until there are sufficient stars to make a working galaxy. As for FTL, the FTL drive should be severely limited to avoid its overuse for traveling to other planets. For example in career, to build an FTL, you will need a TON of science points at the end of the tech tree, will require you to visit multiple planets in order to assemble such a material, and should only work once far enough away from Kerbol similar to a Bussard-Ramjet engine, except its FTL, so more like a jump drive. If not, creating wormholes at the end of the tech tree can do too.

[NovaSilisko]

No need for FTL at all. Just assume the speed of light is the same as in our universe, then you can travel at speeds far slower than light using plausible technology (such as fusion rockets, perhaps, or laser propulsion. I'm partial to nuclear pulse propulsion myself though, it just seems like the sort of thing kerbals would embrace without really questioning), and still arrive in other solar systems in a reasonable timeframe. If we shrink down interstellar distances by 10x, then Proxima Centauri would be 0.4 ly distant. At that distance, going a relatively modest 0.1c means a trip time of 4 real-world years... the interstellar distances could be reduced even further without much issue, as the solar systems are quite small anyway. You could do it on the existing timewarp levels, even (and to help the time go faster, go back home and do some other missions while your starship is in transit)

As for populating the universe, the same principle as generating planet terrain can be used - do it procedurally, keeping the seed the same for everyone so everyone can explore the same world.

[AmpsterMan]

No need for FTL at all. Just assume the speed of light is the same as in our universe, then you can travel at speeds far slower than light using plausible technology (such as fusion rockets, perhaps, or laser propulsion. I'm partial to nuclear pulse propulsion myself though, it just seems like the sort of thing kerbals would embrace without really questioning), and still arrive in other solar systems in a reasonable timeframe. If we shrink down interstellar distances by 10x, then Proxima Centauri would be 0.4 ly distant. At that distance, going a relatively modest 0.1c means a trip time of 4 real-world years... the interstellar distances could be reduced even further without much issue, as the solar systems are quite small anyway. You could do it on the existing timewarp levels, even (and to help the time go faster, go back home and do some other missions while your starship is in transit)

As for populating the universe, the same principle as generating planet terrain can be used - do it procedurally, keeping the seed the same for everyone so everyone can explore the same world.

Well... at 0.4 ly I can see that being a fun mechanic actually. I wonder how difficult it may be to get the accuracy of the simulation at those extremes though. I've seen my trajectory wobble a lot when just going to another planet. How much would that affect going to another system?

[vger]

Well... at 0.4 ly I can see that being a fun mechanic actually. I wonder how difficult it may be to get the accuracy of the simulation at those extremes though. I've seen my trajectory wobble a lot when just going to another planet. How much would that affect going to another system?

Why would the game need concern itself with anything once you were outside Eeloo's influence? Unless we end up with a Kuipur belt (even then, the effects are negligible unless you have a direct hit, which is VERY unlikely)) I don't know if KSP currently does this, but it would be very efficient if while doing its calculations, it completely ignores bodies that have absolutely NO chance at influencing your craft/s.

[NovaSilisko]

Well... at 0.4 ly I can see that being a fun mechanic actually. I wonder how difficult it may be to get the accuracy of the simulation at those extremes though. I've seen my trajectory wobble a lot when just going to another planet. How much would that affect going to another system?

It probably would require some new system for on-rails movement. Unless there's a gravitational center to the galaxy, Keplerian orbits wouldn't apply... even then, they don't, really. Everything orbits at roughly the same speed, it seems, no matter where in the milky way you are. As well as that, stars sort of bob in and out of the plane of the galaxy multiple times per orbit. However, all of those things are on such long timescales that they're not even worth simulating. It would just need a system to keep the ship traveling in basically a straight line til it encounters a star's SOI.

I don't know if there's anything that can be done to fix a lot of the inherent accuracy issues though, unless you somehow found a way to make PhysX use double precision (good luck with that). 0.23.5 has cut down on them somewhat though, I've noticed. So it perhaps wouldn't be too big of an issue.

[NERVAfan]

We could just give the Sun a small binary companion (red dwarf maybe) with its own planetary system. It could have its own enormous SOI within the Sun's SOI.

If we get a second gas giant at maybe 1.5 or 2x Jool's distance from the Sun, then I'd suggest putting the second star at maybe 5-10x Jool's distance. It could have some 'weirder' and/or 'hard mode' planets like a planet in an orbit inclined 90 degrees to the rest of the system, a super-Eve with even denser atmosphere, a planet in an ultra close orbit to the star...

[KerikBalm]

Yea, if we talk about binary (or even trinary) start systems, it becomes feasible, but then you might call it all just one big solar system.

I'm thinking something like the Centauri system, with planets (so far there have been no observatios of planets in that system, and it is the closest system, so... maybe they unusual star configuration has resulted in a planetless system, or maybe they are there afterall)

[Rusty6899]

If we shrink down interstellar distances by 10x, then Proxima Centauri would be 0.4 ly distant. At that distance, going a relatively modest 0.1c means a trip time of 4 real-world years.

This is a debatable point. Firstly, it would take a long time to speed up to 0.1C (and slow down when you get there), meaning that a burn would last months or years. Secondly, I'm not sure if you can calculate time taken as simply as distance/speed = time for interstellar transfers. I think you would basically be trying to get a periapsis as close to the sun as possible and burning to raise your apoapsis until it is outside the sun's SOI.

I find it a bit difficult to justify allowing ships with 30,000+km/s of delta-V.

Edited April 11, 2014 by Rusty6899

[KerikBalm]

Nuclear (fission or preferably fusion) could easily get there.

Orion drives in KSP!

[Daveroski]

Generation Ships.

Big BIG ships. Housing families.

Might take a few generations to get there.

Steady efficient engine gradually increasing speed to just before halfway.

Then turn the ship around and start slowing down.

Good chance everyone will be dead on arrival. Disease in a closed system being the most likely candidate.

But there is always murder and sabotage from some poor crazy nutjob.

Right now on KSP we have the ability to build planetary bases. Where the same type of problems exist but kerbals are immune to most diseases and rarely get any crazier than the craziest on record.

So.. I think modular generation ships would be the best way to go.

[tntristan12]

I would love to see some implementation of special relativity to make trips seem even shorter. I'm sure it can be done, or at least faked reasonably.

[Tery215]

It could work with space scaling.

For instance, a spacecraft can enter the "X Zone", a place dominated by [insert celestial body]. Inside this zone, space is 4 times bigger and it takes 4 times longer to reach the other side than otherwise.

Though this would be extremely difficult to render and would make no sense. Possibly a click -> change map view to "X Zone" and a map switch whenever currently controlled/observed spacecraft enters the "X Zone". Plus a mysterious intangible black/green/white/red shell surrounding the "X Zone".

[tjakz]

I'm really new to this game, but I love it and would love to see more solar systems added without using FTL due to this being the Galactic speed limit. I'm not the smartest person in the world but I haven't read anything in these blogs about "Time dilation"?? Why wouldn't SQUAD put this mechanic into the game? simple term the faster you go the slower time gets. here's how I see it playing out in the game. Once you leave the solar system you start playing with two different timelines. one time line would be based off of Kerbal time then the other time line would be based off of the spaceship time. let's just say that we can get a spaceship up to 99 percent of the speed of light. If we send that space ship to a different solar system and watch it leave from our point of view 10+ years will pass before The spaceship makes it to a different solar system. but if we were riding that same spaceship only maybe one or two years will pass by before we made it to the other solar system. So now we have two different timelines. If that same spaceship traveled back to Karbel at 99% speed of light the person riding that spaceship would only have aged about three to five years but the time that passed on Kerbal would be 30 to 50 years so if you returned back to Kerbal then you would have to have the two different timelines sync back up again (much like the system to sync time in the Multiplayer mode). with all that said most trips to different solar systems would be only a one way trip, better pack a lunch.

[NERVAfan]

Yea, if we talk about binary (or even trinary) start systems, it becomes feasible, but then you might call it all just one big solar system.

Sure, but it still lets you have more stars and planets.

I'm thinking something like the Centauri system, with planets (so far there have been no observatios of planets in that system, and it is the closest system, so... maybe they unusual star configuration has resulted in a planetless system, or maybe they are there afterall)

Well, there is actually a debated report of a sizzling planet (3.4 day year) around Alpha Centauri B. It hasn't been confirmed yet by other astronomers, and some have tried to find it and not been able to, so maybe not...

In any case, there have been models/studies saying that planets are stable in that system as long as they are close enough to one of the two main stars (Proxima hardly counts as it's so far away, like a fifth of a light year). Earthlike orbits are supposed to be stable, and there is actually a project looking for them (FINDS Exo-Earths, run by Debra Fischer... the Planetary Society has been raising money for it), but it's currently taking a hiatus to improve equipment and because A and B stars are now too close together and are interfering with the observations.

http://www.planetary.org/blogs/bruce-betts/20140401-update-on-the-search-for-planets.html (Planetary Society blog update on the project from just a week ago where they talk about the hiatus, and not being able to find the reported really close planet)

Nuclear (fission or preferably fusion) could easily get there.

Orion drives in KSP!

We already have fission rockets (nuclear thermal), that's what the LV-N is. Fission rockets are great compared to chemical rockets, and some hypothetical/more advanced types, like gas-core, could do significantly better than the solid-core NTR that the LV-N represents, but it's still only a few thousand seconds Isp, and that's not enough for interstellar.

I am always a fan of Orion drives, but even they are slow over interstellar distances. Workable as a generation ship (or maybe with future advances in anti-aging/life-extension), but only then. I think they are supposed to max out at something like 3%-5% light speed, even for highly advanced versions, which would mean about 85-150 years to Alpha Centauri, even scaled down at 10:1 that's ten or fifteen years... at 100,000x time warp 10 years compresses to about 53 minutes, assuming my math is right. That's long... but hmm, not as bad as I expected, and if they could add 500,000x or 1,000,000x warp (maybe once you get beyond a certain distance from Kerbol, interstellar-only or something), you could drop it much further.

But the real problem is ...

This is a debatable point. Firstly, it would take a long time to speed up to 0.1C (and slow down when you get there), meaning that a burn would last months or years.

....this. Really long non-time-warped burn times.

I think compressing distances much more by creating a multiple star system (or just say Kerbol is in a really close star cluster, but at the kind of distances I think make sense, they'd probably be gravitationally bound anyway) is a better option.

Plus, I'm not sure if the game could handle a really large number of stars and planets. KSP planets are not Spore planets, which were tiny (and probably had randomly generated surfaces too, though I'm not 100% sure). As awesome as a whole cluster or even galaxy would be, I think 2-3 stars and 10-20 planets would be a very full system.

And a minor nit-pick...

Good chance everyone will be dead on arrival. Disease in a closed system being the most likely candidate.

But there is always murder and sabotage from some poor crazy nutjob.

Actually, I think disease would be very unlikely to be a problem. Assuming you are careful (quarantine before boarding) there will be very little disease, because once they're embarked... there's no one outside the small population to catch anything from, and the generation ship is tiny compared to Earth so there will be vastly fewer opportunities for diseases to jump from animals to humans. (Especially if you are careful to bring healthy animals...)

[Comrade Jenkens]

Maybe one much larger star with several smaller ones orbiting it? Each would have their own planetary system.

[Yoha]

Maybe one much larger star with several smaller ones orbiting it? Each would have their own planetary system.

This is actually a pretty good idea. Considering the plausible sizes for stars, it would be possible in reality even though I do not think we have observed such a situation (which may incentive the developers not to accept it).

[Anton P. Nym]

A while ago I saw a map (fan generated?) for the solar system in the Firefly TV show... the writers there insisted they didn't have FTL but travel between several habitable worlds was a matter of days or weeks, which gave a lot of the more science-literate folks pause.

The map postulated a quaternary star system with a large-ish (A-class?) primary and two smaller (K-class?) secondary stars nearby, each with worlds in their own habitable zones, plus a distant minor star (M-class?) with couple of large gas giants whose radiated heat created their own small habitable zones. It'd be esoteric but not completely ridiculous... and if you want travel between stars in KSP that doesn't need "magic" drives, it's as good a model as any.

-- Steve

[Yoha]

I really like the idea. It solve all the previous issues of having few stars in a galaxy, too long burns or traveling distances, and avoid having a binary system (which would imply a rethink of a part of KSP's engine): the whole thing should be relatively easy to implement by adding one more level of orbit. The celestials bodies on the map are obviously not to scale but the distances between the stars still seems a little short compared to the ones of the planets.

[KASASpace]

Perhaps an Orion Drive?

It could travel ~four light years in 130 years.

So, with a lot of time acceleration, coupled with a way to accelerate too.....

[NERVAfan]

Multiple star systems with lots of stars are totally possible (Castor has six) but they don't look like the Firefly map. In reality, you don't get (or at least we've never seen, AFAIK) several little stars orbiting a big star like a planetary system.

In any system that's stable enough to have evolved complex life (as Kerbin has), heck probably even to have gotten planets past the initial formation phase (don't know the exact timelines), it breaks down into binaries or single stars, and the different binaries are far enough apart to treat each other as single objects.

Alpha Centauri, triple star system, is a binary (A and + a distant companion (Proxima) orbiting the binary as if it was one object.

Castor, a six-star system, is a binary of close binaries, itself orbited by a distant binary.

Of course, in KSP, we don't have N-body physics; the system treats the Sun/Kerbol as a fixed central point. So probably the option for minimum physics breakage is to give Kerbol a fairly close companion much smaller in mass (a red-dwarf scaled to KSP-scales) with its own very close-in planetary system; the smaller the companion is, the less its orbiting Kerbol rather than both orbiting a mutual barycenter will diverge from reality.

If we want a third star, it should be significantly farther away (don't know what's good for stability; maybe at least an order of magnitude? I'm not an astrophysicist....) Of course, it would actually orbit Kerbol rather than the Kerbol-companion barycenter, but what can you do...

So maybe you could have something like...

Existing system from Kerbol out to Jool... (~68 million km per the Wiki)

"Gas Planet 2" (with Eeloo as a moon), in a circular orbit a bit beyond Eeloo's current semi-major axis (~90 million km), say at 108 million km, RL Venus's semi-major axis

--big gap--

New system, centered on a 'red-dwarf' maybe 70,000km radius (if we scale down from Kerbol) or significantly smaller (if we scale up from Jool) say 1 billion km from Kerbol (between Jupiter and Saturn in RL)

Innermost planet, super-close, with lava oceans that destroy ships and continents of higher-melting-point rocks

Tidally locked planet with an Earthlike star-facing hemisphere

Super huge rocky planet (1000km+ radius) with 10 atm surface pressure and 2.5 or 3 g at surface

Ice-giant (Kerbal-scaled, maybe 2400km radius)

And then, if a third system is added, put it at more like 10 billion km... about where Eris is in RL...

[CaptainKipard]

Several months ago there was a very well developed suggestion thread where people designed a trinary and quaternary star system like the one in Battlesta Galactica. I would like to see that developed first. It's a nice middle ground between interplanetary, and interstellar travel.

[Ghost13]

Why do we even need the other stars? Several more planets and moons can be added to the existing solar system and if you want a distance challenge than some sort of minor planet can be placed at the distance of 0.1-0.3 ly from the sun. Even if there will be some star systems it would be virtually impossible to explore them properly with usual kerbal technology and if some new propulsion will be introduced that will alow such a dV budgets and speeds it will make any mission inside the system way too easy. There is some potential in beamed power and plasma engine from Interstellar Quest, it's also probably feasible with use ketane or other in-sito resourses (or both) but I would rather like to see the current planets to be more developed such as weather, seasons, more landscape variations, e.t.c. than new solar systems.