How will interstellar travel work?

[M_Rat13]

I ask because, in KSP 1, you aren't designed to leave the solar system without either glitches, or a lot of time spent accelerating. But, in KSP 2, it is intended that you leave the solar system. However, what is stopping you, for example, not pointing towards an new star system, and just going off into the void of empty space? While it might be funny to fling a spacecraft away, never to be seen again, if it happened by accident, it could be really annoying. 

So, will there be some sort of on the rails paths you can't deviate from between stars, or have the given us absolute freedom that may end up in disaster?

[Bartybum]

3 minutes ago, M_Rat13 said:

if it happened by accident, it could be really annoying.

Well then you'd best learn not to make mistakes. What's stopping you from flinging yourself into an escape from the Kerbol system at the moment? Nothing

[Spaceception]

Probably the same way it works now with solar system/advanced propulsion mods: big ships, and lots of timewarp, but this time with new UI and better performance So you could pick some of those up, and by the time KSP 2 rolls around, you'll know what to do.

[M_Rat13]

26 minutes ago, Bartybum said:

Well then you'd best learn not to make mistakes. What's stopping you from flinging yourself into an escape from the Kerbol system at the moment? Nothing

It isn't an intended feature, and you can only really do it if you are aiming to do it. The velocity difference between going to a planet, and escaping Kerbol, is vast. In the new game though, it's an intended feature, and you will be aiming to escape Kerbol anyway, so if you miss the star you are aiming for, boom, you're in the void. You miss a planet in KSP 1, All that happens is that you orbit Kerbol.

[Bartybum]

40 minutes ago, M_Rat13 said:

It isn't an intended feature, and you can only really do it if you are aiming to do it. The velocity difference between going to a planet, and escaping Kerbol, is vast. In the new game though, it's an intended feature, and you will be aiming to escape Kerbol anyway, so if you miss the star you are aiming for, boom, you're in the void. You miss a planet in KSP 1, All that happens is that you orbit Kerbol.

Ohh, I think I understand - you're referring to what happens if you escape the sphere of influence of either star, aren't you? In that case, my apologies for the condescending reply

It's a good question to be honest. Realistically, I can see a few options (that really depend on how the interstellar group will be modelled):

• The stars all orbit a black hole: this would be problematic as over time, the systems' relative positions are going to change, therefore changing the difficulty of interstellar travel. If you miss a star, you end up orbiting the black hole.
• The stars all orbit a black hole at the same orbital SMA, but at different inclinations, eccentricities etc.: This would be simple, but kinda weird and unrealistic. I could potentially see this happening. Same thing - miss a star, you orbit the black hole.
• The stars all orbit each other (a barycentre): You'd need to employ some sort of N-body calculations.
• The stars are all frozen in space, and you're taken along a straight path to the next SOI. I see this as the likeliest option, since interstellar voyages are likely going to take on the order of decades, and to make that feasible you'll want to get to the next star as fast as you can. They'll probably space the stars far enough to be approximated as relatively stationary, since your motion is going to be orders of magnitude greater than that of the stars. In this case, you'd just keep going in the same direction, which makes sense since you're outside of the significant sphere of influence and hence your path isn't going to be changed much at the speeds you're going.

Edited August 26, 2019 by Bartybum

[GoldForest]

19 minutes ago, Bartybum said:

Ohh, I think I understand - you're referring to what happens if you escape the sphere of influence of either star, aren't you? In that case, my apologies for the condescending reply

It's a good question to be honest. Realistically, I can see a few options (that really depend on how the interstellar group will be modelled):

• The stars all orbit a black hole: this would be problematic as over time, the systems' relative positions are going to change, therefore changing the difficulty of interstellar travel. If you miss a star, you end up orbiting the black hole.
• The stars all orbit a black hole at the same orbital SMA, but at different inclinations, eccentricities etc.: This would be simple, but kinda weird and unrealistic. I could potentially see this happening. Same thing - miss a star, you orbit the black hole.
• The stars all orbit each other (a barycentre): You'd need to employ some sort of N-body calculations.
• The stars are all frozen in space, and you're taken along a straight path to the next SOI. I see this as the likeliest option, since interstellar voyages are likely going to take on the order of decades, and to make that feasible you'll want to get to the next star as fast as you can. They'll probably space the stars far enough to be approximated as relatively stationary, since your motion is going to be orders of magnitude greater than that of the stars. In this case, you'd just keep going in the same direction, which makes sense since you're outside of the significant sphere of influence and hence your path isn't going to be changed much at the speeds you're going.

I think it will most likely work like this mobile game I used to play called Space Agency. In it you had certain speeds at which you got captured by planet or moons SOI's. Go to fast and you shot last them, slow down just enough and you get captured. Of course, I'd imagine KSP 2's thing to be much more refined than just hit a certain speed and get captured.

I'd also imagine aling shots would be super helpful, especially around Jool, but sling shot timings are hard to do, especially when planned out.

[M_Rat13]

55 minutes ago, Bartybum said:

Ohh, I think I understand - you're referring to what happens if you escape the sphere of influence of either star, aren't you? In that case, my apologies for the condescending reply

It's a good question to be honest. Realistically, I can see a few options:

• The stars all orbit a black hole: this would be problematic as over time, the systems' relative positions are going to change, therefore changing the difficulty of interstellar travel.
• The stars all orbit a black hole at the same orbital SMA, but at different inclinations, eccentricities etc.: This would be simple, but kinda weird and unrealistic. I could potentially see this happening.
• The stars all orbit each other (a barycentre): You'd need to employ some sort of N-body calculations for when you're between the two stars.
• The stars are all frozen in space, and you're taken along a straight path to the next SOI. I see this as the likeliest option, since interstellar voyages are likely going to take on the order of decades, and to make that feasible you'll want to get to the next star as fast as you can. They'll probably approximate the stars as being relatively stationary, since your motion is going to be a fair few orders of magnitude greater than that of the stars.

Thinking about it, the stars orbiting a black hole could be really cool. It'd probably be a pain to code a black hole, but it'd definitely be something unique to visit.

[Guest]

One thing I wonder about though is burn times. Getting to interstellar speeds requires really long burns and the engines will have to be ultra-high-Isp and therefore likely very low TWR too; with some realistic-ish interstellar ship designs you'd have burns that last the entire trip, accelerating to the halfway point then decelerating the rest of the way. This isn't really feasible with the current UI for burns which assumes that the impulse is instantaneous and only lets you physics warp during the burn.

[GoldForest]

12 minutes ago, Brikoleur said:

One thing I wonder about though is burn times. Getting to interstellar speeds requires really long burns and the engines will have to be ultra-high-Isp and therefore likely very low TWR too; with some realistic-ish interstellar ship designs you'd have burns that last the entire trip, accelerating to the halfway point then decelerating the rest of the way. This isn't really feasible with the current UI for burns which assumes that the impulse is instantaneous and only lets you physics warp during the burn.

There's a rumor that warp thrusting( Time warp while engine is on) will be allowed for certain engines. Again, just a rumor. 

Although, a faster way to gain speed would be to set up multiple sling shots. Heck, if you can survive Jool's atmosphere, Jool can kick your craft out pretty far. I would imagine that would be the easiest way to get Interstellar. Slingshot using Jool, once in Jool's atmosphere turn on your engines to lose as little speed as possible, and then go out into interstellar space. Of course, if you want to play it save, slingshot using Jool, but just skim the atmosphere. At periapsis, start burning to gain more speed. 

The closer to Jool you get the faster and farther you'll go. 

Edited August 26, 2019 by GoldForest

[Guest]

8 minutes ago, GoldForest said:

Although, a faster way to gain speed would be to set up multiple sling shots. Heck, if you can survive Jool's atmosphere, Jool can kick your craft out pretty far. I would imagine that would be the easiest way to get Interstellar. Slingshot using Jool, once in Jool's atmosphere turn on your engines to lose as little speed as possible, and then go out into interstellar space. Of course, if you want to play it save, slingshot using Jool, but just skim the atmosphere. At periapsis, start burning to gain more speed. 

That's still orders of magnitude off interstellar speeds. Say you want to reach 0.01c. That's 3,000,000 m/s. At acceleration of 0.1g  (about 1 m/s^2)  -- high for a deep-space thruster -- it would take 3 million seconds to get there. That's about a month of constant thrust. If you have a stupidly powerful engine that can do 1 g, or if you're happy with 0.001c, that's still three days of constant thrust. There is no amount of slingshotting around Jool that'll get you anywhere close to it, even a sun dive would take a very small bite out of it.

Edited August 26, 2019 by Guest

[GoldForest]

16 minutes ago, Brikoleur said:

That's still orders of magnitude off interstellar speeds. Say you want to reach 0.01c. That's 3,000,000 m/s. At acceleration of 0.1g  (about 0.1 m/s^2)  -- high for a deep-space thruster -- it would take 30 million seconds to get there. That's about one year of constant thrust. If you have a stupidly powerful engine that can do 1 g, that's still a month of constant thrust. There is no amount of slingshotting around Jool that'll get you anywhere close to it, even a sun dive would take a very small bite out of it.

It would still help. 

You also have to remember, we're getting Daedalus, which in IRL could reach 7.5% of C after 2 years, then 12% of C after another 2. 

IIRC the devs said the solar systems are about 1 to 2 either solar years or light years apart from each other. With this in mind, we can assume that Daedalus would be balanced accordingly. 

So, and I'm just guessing too lazy to figure out real math right now, that would be about... 12% of C after... 3 to 4 months, with continual thrust mind you, if they went with light years. Solar years I would imagine we would get up to 12% after a month or two. 

Edited August 26, 2019 by GoldForest

[Guest]

Every little bit helps of course. But burns that long would still need a new UI and system for planning and executing them.

[GoldForest]

12 minutes ago, Brikoleur said:

Every little bit helps of course. But burns that long would still need a new UI and system for planning and executing them.

True, that's why we're getting thrust warping (Time warp but allowing engines to continue to operate)

[Guest]

26 minutes ago, GoldForest said:

True, that's why we're getting thrust warping (Time warp but allowing engines to continue to operate)

That's not enough. The burn planner assumes instantaneous impulse and it works well enough for short burns, you just get a bit of manoeuvring loss. It won't work if you're burning through a significant fraction of your trajectory. You'll need a system that factors in burn time when planning your transfers.

Edit: oh hey, whaddya know:

We’ve had to overhaul the map view and map system to allow you to plan a continuous acceleration trajectory, and of course we’ve had to add a couple more levels of time zoom because many of these voyages take years and we don’t want you to have to literally sit at your computer for years. Although internally we’ve had a bet around whether someone in the community will attempt to run an interstellar mission in real-time! It would take years, but if you have an extra computer that you don’t want to use for anything for a while…

 

From this thread: 

 

Edited August 26, 2019 by Guest

[mk1980]

8 hours ago, M_Rat13 said:

I ask because, in KSP 1, you aren't designed to leave the solar system without either glitches, or a lot of time spent accelerating. But, in KSP 2, it is intended that you leave the solar system. However, what is stopping you, for example, not pointing towards an new star system, and just going off into the void of empty space? While it might be funny to fling a spacecraft away, never to be seen again, if it happened by accident, it could be really annoying. 

So, will there be some sort of on the rails paths you can't deviate from between stars, or have the given us absolute freedom that may end up in disaster?

i guess if ksp 2 uses the same "sphere of influence" mechanic as ksp 1, then the different star systems might simply be embedded inside another larger "galaxy" SOI to have a common frame of reference while travelling through the void. so once you leave the kerbol SOI, you're out in the galaxy SOI until you enter the SOI of one of the other stars.

basically the same concept like when you leave the kerbin SOI and enter the sun SOI until you reach the duna, jool, eve etc. SOI - but one "level" higher

that wouldn't be too far fetched imo. afaik our real solar system orbits the galactic core with an orbital period of 200 million years or so. i guess the same is true for all other stars in the galaxy. since each star has its own orbit, the relative positions / constellations of the stars change over time, but i guess the process is slow enough to be mostly negligible if the sci fi tech used for the interstellar travel in KSP allows travel times measured in years or decades.

[GoldForest]

10 minutes ago, mk1980 said:

i guess if ksp 2 uses the same "sphere of influence" mechanic as ksp 1, then the different star systems might simply be embedded inside another larger "galaxy" SOI to have a common frame of reference while travelling through the void. so once you leave the kerbol SOI, you're out in the galaxy SOI until you enter the SOI of one of the other stars.

basically the same concept like when you leave the kerbin SOI and enter the sun SOI until you reach the duna, jool, eve etc. SOI - but one "level" higher

that wouldn't be too far fetched imo. afaik our real solar system orbits the galactic core with an orbital period of 200 million years or so. i guess the same is true for all other stars in the galaxy. since each star has its own orbit, the relative positions / constellations of the stars change over time, but i guess the process is slow enough to be mostly negligible if the sci fi tech used for the interstellar travel in KSP allows travel times measured in years or decades.

In order for there to be a galactic SOI, there would need to be a black hole in the game. 

[mk1980]

the SOI concept is just a way to model different frames of reference in the unity engine. i doubt the engine requires an actual object in the center of the SOI for it to work. wouldn't have to be a black holy in any case. an abstract "center of mass" object would serve the same purpose (if an object is even required).

i think in old versions of KSP the sun was only a bright spot in the sky and not an actual object and it worked.

also, our sun is like 25,000 lightyears away from the center of the galaxy, so even if the game again shrinks distances to ~1/10th, kerbol would orbit the galactic center in throusands of lightyears distance and the next stars would be 1-2 lightyears from kerbol.

so in normal gameplay it's 3 orders of magnitude further than the interstellar distances you're supposed to be able to traverse. i.e. in practice it doesn't *really* matter what's in the center. i'm sure someone would try (and succeed) to fly to the center just to see what happens, so it would be a perfect spot for an easter egg. home of the kraken maybe :)

[Kaerbanogue]

I think stars will be locked in space. Anyway solar systems are orbiting the center of the galaxy the same way as planets orbit stars but at a larger scale.

But if we consider that it'll take ages for a solar system to make a revolution around the galaxy, they could simplify it by just having still solar systems (I mean their position from each others). 

Any other solutions that are more realistic (N-Body physics, Solar systems orbiting each others...) would make very hard for devs to add more Sol Systems (with dlc for exemple) 

Not a specialist at all, so I could be hugely mistaking, but I think that's the only reasonable way to do it. 

[GoldForest]

2 minutes ago, mk1980 said:

the SOI concept is just a way to model different frames of reference in the unity engine. i doubt the engine requires an actual object in the center of the SOI for it to work. wouldn't have to be a black holy in any case. an abstract "center of mass" object would serve the same purpose (if an object is even required).

i think in old versions of KSP the sun was only a bright spot in the sky and not an actual object and it worked.

also, our sun is like 25,000 lightyears away from the center of the galaxy, so even if the game again shrinks distances to ~1/10th, kerbol would orbit the galactic center in throusands of lightyears distance and the next stars would be 1-2 lightyears from kerbol.

so in normal gameplay it's 3 orders of magnitude further than the interstellar distances you're supposed to be able to traverse. i.e. in practice it doesn't *really* matter what's in the center. i'm sure someone would try (and succeed) to fly to the center just to see what happens, so it would be a perfect spot for an easter egg. home of the kraken maybe

YES! Star Theory! Do this! 

[magnemoe]

5 hours ago, Kaerbanogue said:

I think stars will be locked in space. Anyway solar systems are orbiting the center of the galaxy the same way as planets orbit stars but at a larger scale.

But if we consider that it'll take ages for a solar system to make a revolution around the galaxy, they could simplify it by just having still solar systems (I mean their position from each others). 

Any other solutions that are more realistic (N-Body physics, Solar systems orbiting each others...) would make very hard for devs to add more Sol Systems (with dlc for exemple) 

Not a specialist at all, so I could be hugely mistaking, but I think that's the only reasonable way to do it. 

This an central black hole would make stars move around it and SOI of starts would depend on its mass as they should not overlap it need to be massive and you don't want the stars to move fast. solution is to fix them and use an minimum gravity as and of SOI. 
This also makes it easy to add more star systems over time.

Guess interstellar distances is 1/10 or our but can easy be less. 
But yes an black hole or neutron star would be cool 

[Superfluous J]

12 hours ago, GoldForest said:

In order for there to be a galactic SOI, there would need to be a black hole in the game. 

Naw they just need to add a background SOI into the game and give each star an SOI limit manually.

[Daniel Prates]

23 hours ago, Bartybum said:

Well then you'd best learn not to make mistakes. What's stopping you from flinging yourself into an escape from the Kerbol system at the moment? Nothing

I 'think' there is a limit somewhere. KSP space is not limitless like real space. The ksp wiki says something about that, I am too lazy to go there right now and check it.

Now to the point. The info we already have mentions new late-game tech. What do you guys supose that is? Uber-speculative things like warp etc.? I confess I don't know how I feel about that.

The fact is, even today, getting to bodies beyond Jool is a damn bore, it takes yeeeeeaaaaarrrrrsssss. Players who use LS mods, body/mental health mods, failures mods etc. rarely go there (I assume. I know I don't, except very rarely) because it can be as prohibitive as in real life. 

Now imagine going to other stars! Dayum!

One interesting aspect is whether the stars are static, or if they orbit around some baricenter and thus change position in relation to eachother overtime.

[shdwlrd]

1 hour ago, Daniel Prates said:

Now to the point. The info we already have mentions new late-game tech. What do you guys supose that is? Uber-speculative things like warp etc.? I confess I don't know how I feel about that.

No, if you check out the propulsion thread you'll see that star theory is grounding all engines in the current and near future science and technology. Also from star theory, there won't be any FTL, warp drives or warp gates.

 

Edited August 27, 2019 by shdwlrd
adding link

[Daniel Prates]

7 minutes ago, shdwlrd said:

No, if you check out the propulsion thread you'll see that star theory is grounding all engines in the current and near future science and technology. Also from star theory, there won't be any FTL, warp drives or warp gates.

 

That is probably wise. Keeping this game "newtonian" preserves that "scientific" feel that made the game so loved.