Decaying Orbits

[KSPFanatic102]

On 29/04/2017 at 8:45 PM, ZooNamedGames said:

My expectation is that station keeping would be automatic. Set set it to use LFO, Xenon or monoprop to reset orbit and it uses X based on an equation. Higher, the less you need to.

Basically you can't leave spacecraft at 70,001m anymore, but 250k craft will be almost completely unaffected. 

Doing my math- for 40 years of orbiting at let's say 500,000km (near ISS)- you'd only lose 400km of attitude. That's after 40 ingame years. Plenty of enough time to go to Eeloo and back and to Jool and back with time to spare! That's without station keeping either which could keep it up theoretically indefinitely with refueling missions!

Yes

Believe Dangit, ISP changing mods and Cyrogenic engines are what your after.

But things don't remain in orbit. It's teaching inaccurate science. Might as well just have a single rocket engine for everything if we're going to dull the reality to make it easier. 

The deorbitting process doesn't have to be harsh- just present. I did some math above and you'll see that what I would have in mind is much more mild and less punishing. 

Welcome to the forums! Here we bicker, argue and have lots of fun- IN SPACE!

Well i played KSP since 2013, since my memory is getting full having to reinstall it all over again . and i think i made my account sometime between 1-2 years ago on the forums?

Edited May 22, 2017 by Deddly

[Zeiss Ikon]

I like the idea of orbital decay -- in fact, I was expecting it to help with keeping things cleaned up (minimizing Kessler syndrome) when I first started playing, and was disappointed to find that not only don't low orbits decay, even an orbit that clearly dips into the atmosphere doesn't seem to decay noticeably unless I'm watching/flying the vessel or debris when it passes periapsis.

That said, however, the OP's original proposal is much too rapid.  The kind of orbital decay that matters to us, for game play purposes, is exclusively the kind caused by the fact that the atmosphere doesn't have a well-defined boundary.  There's a phenomenon called "Shuttle glow"  that was first noticed during the early years of the Space Shuttle era, when the first craft with extended surfaces and a way to see them when in flight showed that there was a faint glow at the leading edges (relative to orbital velocity) of everything -- a glow that was eventually attributed to the faint, faint traces of atmosphere that are still found at orbital height of 150+ km above Earth.  This is the same atmospheric trace that causes orbital decay -- but from that kind of height, orbital decay takes months or years to bring an object down to the point where it's in imminent danger of reentry.  Even a very low-density object like a balloon (most affected by drag from the trace atmosphere) takes weeks to come down from Shuttle altitudes, while the ISS, with a very draggy shape and lots of excrescences (solar panels and radiators, for instance) only requires reboosting every couple years.

Realistic orbital decay would be, IMO, a welcome addition to the game, especially if it could be turned off or adjusted in difficulty settings (so people who hate it need not deal with it), and seemingly wouldn't be terrifically difficult to implement -- it's nothing more or less than a constant retrograde acceleration with a very low value dependent on altitude above a body with atmosphere.  It need not even be tied to atmospheric physics (as in how high/fast you are when you start seeing heating effects during aerobraking or reentry), but can be a separate, simplified calculation -- its effect is so small that its becomes negligible once interface begins (say, around 50 km from low orbit velocity around Kerbin in the stock game), and the calculation is a simple bit of arithmetic (which is one of the things computers do best) and ought not to produce a lot of system load.

And with realistic orbital decay, a second stage that I leave in an orbit with 90 km periapsis because I'm unwilling to abandon several hundred m/s of residual dV will eventually deorbit without my intervention, even though it may take a couple Kerbin years for the apoapsis to drop enough to see it happening.

[KSPFanatic102]

2 minutes ago, Zeiss Ikon said:

I like the idea of orbital decay -- in fact, I was expecting it to help with keeping things cleaned up (minimizing Kessler syndrome) when I first started playing, and was disappointed to find that not only don't low orbits decay, even an orbit that clearly dips into the atmosphere doesn't seem to decay noticeably unless I'm watching/flying the vessel or debris when it passes periapsis.

That said, however, the OP's original proposal is much too rapid.  The kind of orbital decay that matters to us, for game play purposes, is exclusively the kind caused by the fact that the atmosphere doesn't have a well-defined boundary.  There's a phenomenon called "Shuttle glow"  that was first noticed during the early years of the Space Shuttle era, when the first craft with extended surfaces and a way to see them when in flight showed that there was a faint glow at the leading edges (relative to orbital velocity) of everything -- a glow that was eventually attributed to the faint, faint traces of atmosphere that are still found at orbital height of 150+ km above Earth.  This is the same atmospheric trace that causes orbital decay -- but from that kind of height, orbital decay takes months or years to bring an object down to the point where it's in imminent danger of reentry.  Even a very low-density object like a balloon (most affected by drag from the trace atmosphere) takes weeks to come down from Shuttle altitudes, while the ISS, with a very draggy shape and lots of excrescences (solar panels and radiators, for instance) only requires reboosting every couple years.

Realistic orbital decay would be, IMO, a welcome addition to the game, especially if it could be turned off or adjusted in difficulty settings (so people who hate it need not deal with it), and seemingly wouldn't be terrifically difficult to implement -- it's nothing more or less than a constant retrograde acceleration with a very low value dependent on altitude above a body with atmosphere.  It need not even be tied to atmospheric physics (as in how high/fast you are when you start seeing heating effects during aerobraking or reentry), but can be a separate, simplified calculation -- its effect is so small that its becomes negligible once interface begins (say, around 50 km from low orbit velocity around Kerbin in the stock game), and the calculation is a simple bit of arithmetic (which is one of the things computers do best) and ought not to produce a lot of system load.

And with realistic orbital decay, a second stage that I leave in an orbit with 90 km periapsis because I'm unwilling to abandon several hundred m/s of residual dV will eventually deorbit without my intervention, even though it may take a couple Kerbin years for the apoapsis to drop enough to see it happening.

I Mentioned Earlier to the other people about the Modifiable Setting that they can turn off and on like 4 times on the post , but the message doesn't seem to be clear . But anyways thanks for the support , i appreciate it

[tater]

Well, some people have reasonable objections, and some have reasonable support. 

I agree that it has some merit, but I think it would require some limitation to avoid it being tedious. If KSP actually had a "manage a space program" component (what career is supposed to be, but isn't), then such boosting operations would be something the staff would simply do to craft in vulnerable orbits, that had propellant. Since that is not a thing, then I think that it would be limited to atmospheric drag, and there should be a point at which an orbit is safe.

Right now, a suborbital piece of debris doesn't mean anything at all unless you put it in focus, and fly it to oblivion manually. To start with, any orbit below the atmosphere should decay, right? If you agree that your debris with a periapsis of 1000m should decay and deorbit, then we're just talking about where that gradient should end.

I agree with @Zeiss Ikon. 

22 minutes ago, ZooNamedGames said:

Believe Dangit, ISP changing mods and Cyrogenic engines are what your after.

Nope, none of the above are, though I play with boiloff, cryo, etc all the time. Dangit is too severe, it's basically more LOLSPLOYKERBALS and you entirely miss the point. 

The point is design tradeoffs making the game actually interesting. If the goal is to get to A and back again, there is generally a simple way to do it with something as silly as the mk1 pod. I'd generally prefer to make it more complex so that getting even to the mun actually feels like an accomplishment.

[KSPFanatic102]

But the problem is that if you're considering a 100km decay altitude then what about Jool , put to consideration , i think it should be anything below 300-400 km

4 minutes ago, Space_taco said:

But the problem is that if you're considering a 100km decay altitude then what about Jool , put to consideration , i think it should be anything below 300-400 km @tater

oops they got cloned :l

Edited April 29, 2017 by Space_taco

[Zeiss Ikon]

Just now, Space_taco said:

But the problem is that if you're considering a 100km decay altitude then what about Jool , put to consideration , i think it should be anything below 300-400 km

The thicker the planet's atmosphere, the higher the decay force -- but the higher its surface gravity, the faster the decay force drops off.  Generally, the existing "limit" of atmosphere for the stock bodies with atmospheres (Eve, Kerbin, Duna, Jool, and Laythe) can be taken to be the same atmospheric density, and the dropoff of decay above that is dependent mainly on the acceleration of gravity adjusted for altitude (which determines how fast atmospheric density lapses).  Eve has higher gravity than Kerbin, but a much thicker atmosphere, so its interface is higher, but the decay force drops off a little faster.  The same is true, in spades, for Jool (complicated by not having an actual surface).  This is still just a simple arithmetical calculation, with variables for each body (gravity and radius to atmospheric limit).  This gives a retarding force, just as drag does in the atmosphere proper, but with a far lower value and little or no consideration to shape -- only frontal area and density really affect it (you could include a factor for number of shock fronts, since it'll always be supersonic for the medium, but that may be an unnecessary complication).

[OrbitalBuzzsaw]

1 hour ago, tater said:

 I intentionally proposed a simple complication that people like you might actually be able to deal with.

Simple? No. Very wrong. Who wants to have to stop warping every month to reposition all your carefully aligned comsats?

Edited April 29, 2017 by OrbitalBuzzsaw

[ZooNamedGames]

15 minutes ago, tater said:

Well, some people have reasonable objections, and some have reasonable support. 

I agree that it has some merit, but I think it would require some limitation to avoid it being tedious. If KSP actually had a "manage a space program" component (what career is supposed to be, but isn't), then such boosting operations would be something the staff would simply do to craft in vulnerable orbits, that had propellant. Since that is not a thing, then I think that it would be limited to atmospheric drag, and there should be a point at which an orbit is safe.

Right now, a suborbital piece of debris doesn't mean anything at all unless you put it in focus, and fly it to oblivion manually. To start with, any orbit below the atmosphere should decay, right? If you agree that your debris with a periapsis of 1000m should decay and deorbit, then we're just talking about where that gradient should end.

I agree with @Zeiss Ikon. 

Nope, none of the above are, though I play with boiloff, cryo, etc all the time. Dangit is too severe, it's basically more LOLSPLOYKERBALS and you entirely miss the point. 

The point is design tradeoffs making the game actually interesting. If the goal is to get to A and back again, there is generally a simple way to do it with something as silly as the mk1 pod. I'd generally prefer to make it more complex so that getting even to the mun actually feels like an accomplishment.

So you don't make your builds capable of failures?

[KSPFanatic102]

2 minutes ago, OrbitalBuzzsaw said:

Simple? No. Very wrong. Who wants to have to stop warping every month to reposition all your carefully aligned comsats?

again , you can turn of and on the setting of orbital decay , also it depend on what planet you're orbiting and the altitude ,and the mode .

you could have full access to turn orbital decay either on or off or customize it in custom mode from 0%-100% Efficiency , even if it was 100% , @ZooNamedGames Explained on Page 1 that if i put some probe or satellite on 500km orbit it would fully decay in 40 year (Ingame) time at 100% Efficency  which is more than enough to reach planets like Jool and back with Spare time , and the Orbital decay would be different on Duna than on Kerbin , For Example if it takes 40 years (INGAME) to deorbit a satellite on Kerbin , it could be 80 years (INGAME) to deorbit it in Duna .

[ZooNamedGames]

9 minutes ago, OrbitalBuzzsaw said:

Simple? No. Very wrong. Who wants to have to stop warping every month to reposition all your carefully aligned comsats?

Why not make it automatic based on fuel preferences?

[KSK]

5 minutes ago, OrbitalBuzzsaw said:

Simple? No. Very wrong. Who wants to have to stop warping every month to reposition all your carefully aligned comsats?

If your comsats are being affected by atmospheric drag they're too low. As in too low to be useful. Unless you're flying an Iridium constellation for roleplaying reasons, you're better off with a smaller cluster of sats in a high enough orbit that they've got line of sight on each other. Which should be plenty to keep them out of atmosphere.

 

[tater]

10 minutes ago, OrbitalBuzzsaw said:

Simple? No. Very wrong. Who wants to have to stop warping every month to reposition all your carefully aligned comsats?

Carefully aligned comsats? And you complain about realism? The com system in stock now, and the mod that people used before are nonsense. Eeloo is inside the orbit of Venus. There are no comm issues possible in ksp short of LOS, talk about needless complication...

[SilverWolf]

42 minutes ago, ZooNamedGames said:

But things don't remain in orbit. It's teaching inaccurate science. Might as well just have a single rocket engine for everything if we're going to dull the reality to make it easier.

If we're going to lose sleep over inaccurate science, then there are existing issues that should be resolved before we haggle over adding new content.  The first one that hits very close to home is the IntakeAir resource.  Essentially, we're teaching that if you slap enough intakes on an engine, it'll run, and a jet engine is nothing more than a rocket that uses air, when it's something that's so much more complicated.

It's not that this is a bad idea, it just belongs in a standalone modification, and not the base game itself.  We want to keep the learning curve for new players as shallow as feasible, given this is rocket science, to maintain interest.  Players desiring a more difficult experience can install mods, as most of us have.

[tater]

3 minutes ago, ZooNamedGames said:

So you don't make your builds capable of failures?

I do in some of my builds (I have about 6 right now). The current mods don't do it right, it needs to be there all the time, but rare, and it needs to consider different parts with different risks. The solution I end up using short of that is to use the right propellants for the right application in the right timeframe. So early mun missions use hyperbolic props on the csm and lander.

[ZooNamedGames]

1 minute ago, Verran said:

If we're going to lose sleep over inaccurate science, then there are existing issues that should be resolved before we haggle over adding new content.  The first one that hits very close to home is the IntakeAir resource.  Essentially, we're teaching that if you slap enough intakes on an engine, it'll run, and a jet engine is nothing more than a rocket that uses air, when it's something that's so much more complicated.

It's not that this is a bad idea, it just belongs in a standalone modification, and not the base game itself.  We want to keep the learning curve for new players as shallow as feasible, given this is rocket science, to maintain interest.  Players desiring a more difficult experience can install mods, as most of us have.

Granted it is a space game (Kerbal Space Program), so lacking information on jet engines may warrant inaccuracies. Whereas orbital decay fits within the space spectrum.

2 minutes ago, tater said:

I do in some of my builds (I have about 6 right now). The current mods don't do it right, it needs to be there all the time, but rare, and it needs to consider different parts with different risks. The solution I end up using short of that is to use the right propellants for the right application in the right timeframe. So early mun missions use hyperbolic props on the csm and lander.

Could always add your own content to the mod to add or remove failures to your liking.

[KSPFanatic102]

8 minutes ago, Verran said:

If we're going to lose sleep over inaccurate science, then there are existing issues that should be resolved before we haggle over adding new content.  The first one that hits very close to home is the IntakeAir resource.  Essentially, we're teaching that if you slap enough intakes on an engine, it'll run, and a jet engine is nothing more than a rocket that uses air, when it's something that's so much more complicated.

It's not that this is a bad idea, it just belongs in a standalone modification, and not the base game itself.  We want to keep the learning curve for new players as shallow as feasible, given this is rocket science, to maintain interest.  Players desiring a more difficult experience can install mods, as most of us have.

a thought just came up on my mind

since there's air in some planets other than kerbin

shouldn't Plane engines work?

[KSK]

7 minutes ago, Verran said:

If we're going to lose sleep over inaccurate science, then there are existing issues that should be resolved before we haggle over adding new content.  The first one that hits very close to home is the IntakeAir resource.  Essentially, we're teaching that if you slap enough intakes on an engine, it'll run, and a jet engine is nothing more than a rocket that uses air, when it's something that's so much more complicated.

It's not that this is a bad idea, it just belongs in a standalone modification, and not the base game itself.  We want to keep the learning curve for new players as shallow as feasible, given this is rocket science, to maintain interest.  Players desiring a more difficult experience can install mods, as most of us have.

If we're going to lose sleep over inaccurate science then we'd better stop playing stock KSP right now. I'm struggling to think of any aspect of real flight or spaceflight that it doesn't simplify, abstract away or grossly overpower for the sake of gameplay.

[tater]

My machine is old, so I tend to pick and choose mods. In addition, some that I usually like to play with are not always compatible with the mods we are now talking about. Stock rockets are too ugly to even look at, so my most commonly played builds have most stock rocket stuff actually deleted to avoid clutter.

That is not related to this thread. Do you think that a spent stage with a periapsis of 60km should decay in stock, yes or no?

[KSPFanatic102]

3 minutes ago, tater said:

My machine is old, so I tend to pick and choose mods. In addition, some that I usually like to play with are not always compatible with the mods we are now talking about. Stock rockets are too ugly to even look at, so my most commonly played builds have most stock rocket stuff actually deleted to avoid clutter.

That is not related to this thread. Do you think that a spent stage with a periapsis of 60km should decay in stock, yes or no?

In Kerbin Orbit? Definitley

also i use Procedural Parts Fuel Tanks instead of ugly stock ones , like the 2.5m Tank that looks like a Oil Drum i forgot what was it name

 

Edited April 29, 2017 by Space_taco

[Tex]

8 hours ago, soulsource said:

Also, there's a mod for that:

 

Pretty much sums up my thoughts on this addition as well. Realistic? Maybe. However, for terms of game playability, I would say it is best left to mods.

[tater]

Shouldn't suborbital craft/debris eventually deorbit in stock, vs forcing a player to select and remove them?

If you think so, then we're just dickering over the altitude. 

Decay might start at <70km, and get more profound the lower you go. This is 100% compatible with current stock.

[AlamoVampire]

@ZooNamedGames Um you know that the kerbin system is not a 1:1 for our solar system right? So it kinda makes your "dull reality" thing moot. But heres the truth, orbital decay would suck the fun out of ksp and turn it into a game of just constantly micro managing every satellite you have. If you have a few no biggie but if you have dozens? Forget ever running a new mission as your job is now keeping your network up. Literally.

[ZooNamedGames]

14 minutes ago, AlamoVampire said:

@ZooNamedGames Um you know that the kerbin system is not a 1:1 for our solar system right? So it kinda makes your "dull reality" thing moot. But heres the truth, orbital decay would suck the fun out of ksp and turn it into a game of just constantly micro managing every satellite you have. If you have a few no biggie but if you have dozens? Forget ever running a new mission as your job is now keeping your network up. Literally.

No, but a meter is a meter. That hasn't changed.

It's not micromanagement if you let them station keep themselves.

[swjr-swis]

2 hours ago, ZooNamedGames said:

Doing my math- for 40 years of orbiting at let's say 500,000km (near ISS)- you'd only lose 400km of attitude. That's after 40 ingame years.

What is the point of trying to simulate a decay of 400m in 40 years, when the in-game Ap/Pe fluctuate and decay (or gain sometimes) that much in as little as a single orbit? The game as it stands right now does not allow for that kind of subtleties.

To be able to even appreciate the effects, the simulated decay would have to be a few orders of magnitude bigger than what it normally is even given the KSP vs Solar System differences, and significantly bigger than the random error the game code adds without it being intended (what just made my orbit drop half a km? Do I need station keeping, or just wait for it to 'repair' itself on the other side of the orbit...?).

(P.S.: You meant 'm', not 'km'? The ISS would be orbiting behind the moon...)

Edited April 29, 2017 by swjr-swis
PS

[AlamoVampire]

1. Limited fuel. They WILL deorbit. 

2. A meter is a meter sure. But at some point 1 becomes 2 becomes 4 becomes 8, 16, 32, 64, 128, 1km until burned up.

3. Its micro management no matter how you gussy it up.