Does kerbal accurately depict deep space flight?

[mizzou]

I'm wondering, does it accurately depict movement in open space? It seems like no matter what, you need a massive amount of fuel or great planning to get out of the gravitational pull from earth. Once out earths orbit, you are in the general orbit of the solar system. From there, it takes a great amount of fuel to make any reasonable push to get around. Instead of "Hey, I'd like to fly this way" All you can do is just push yourself further and further out of a rotational orbit or recede closer in. No matter what you do, you are always getting pulled in a circle (Or perhaps straight in if you use enough fuel to completely slow yourself down)

It seems like it's nearly impossible to do X-wing style flying around, stopping, speeding up, etc. Everything takes an enormous amount of fuel.


It SEEMS accurate to me, but it's destroying my scifi expectations and wants lol. I sort of wish sometimes, it WASNT so accurate.

 

[Revolution 11]

It is accurate enough. If you want a modern Tie Fighter game, there are some new space exploration games (I can't remember the titles) and there is Star Citizen. Kerbal is supposed to be accurate, that's the whole point. Yes, physics is hard and space exploration is even harder.

There is a reason why only two countries were in the Space Race, the 2 main winners of World War 2. It takes a level of infrastructure and expertise needed to win a war of that magnitude to get anywhere near the moon with humans.

Still not as accurate as NASA simulators which can take into account the pressure and force of the solar wind on a orbit among many parameters.

 

[AyashiKaibutsu]

I've barely played it any, but isn't the whole point mastering the physics? If you could zoom around I suspect it'd get very boring very quickly. Yes, Space flight is difficult and mostly about taking advantage of orbital mechanics. Every ounce of fuel you take into space you need to carry even more fuel to get that extra ounce into space... it's a precious commodity.

 

[Plimogz]

This reminds me of one of last week's XKCDs:

 

[_Rick_]

There is no deep space in KSP, only a single solar system is currently modeled, i.e. only "close space".

Deep space is usually to be understood to be well beyond heliopause and the gravitational effects of a star.

Also, remember, speed is relative, and mass/inertia is always killing all the fun.
Most sci-fi craft behave in such a way, that inertia is negligible compared to available thrust. One of the earliest games that had some treatment of inertia was Star Control. And even there the low "speed limit" limited the inertia values to low amounts.
I think in some versions of asteroids you could properly accelerate to ridiculous speed, and then have to deal with some inertia. This shows, that even with a fuel cheat on, you can't fly like an airplane/X-Wing in space.

 

[JTsyo]

There is no deep space in KSP, only a single solar system is currently modeled, i.e. only "close space".

Deep space is usually to be understood to be well beyond heliopause and the gravitational effects of a star.

Also, remember, speed is relative, and mass/inertia is always killing all the fun.
Most sci-fi craft behave in such a way, that inertia is negligible compared to available thrust. One of the earliest games that had some treatment of inertia was Star Control. And even there the low "speed limit" limited the inertia values to low amounts.
I think in some versions of asteroids you could properly accelerate to ridiculous speed, and then have to deal with some inertia. This shows, that even with a fuel cheat on, you can't fly like an airplane/X-Wing in space.

In star Control 2, at least there was the flying saucer that had no inertia. Was interesting fighting with that since you were much more maneuverable.

 

[Revolution 11]

This reminds me of one of last week's XKCDs:

To be fair, the artist's career at NASA involved small-scale robotics, not trajectory planning or inter-planetary navigation. Two completely different skill categories.

 

[JamesV]

The thing with most sci-fi movies, is that fuel is never a consideration. Either they have some kind of advanced power plant that uses barely anything to power it (Star Trek), or fuel isn't even mentioned at all.

That is why they can fly 'straight' to another planet or system; with unlimited fuel, you wouldn't need to plan a route. Without unlimited fuel, you would need to plan a hyperbolic trajectory; ie. slingshot your way out of the system you are in, and 'catch' an orbit around your destination, using gravitational forces to help you speed up and slow down.

I might be wrong about this part, but even if you were able to get to a point outside our solar system, where none of the planets or Sun had any gravitational effect on you, you would still be orbiting something. Our system orbits others, and our little arm of the Milky Way is moving incredibly fast compared to the center. If you were outside our system's sphere of influence, you wouldn't be in a spot that eventually another system would connect with you, but instead be in an orbit that would 'take you along'.

 

[shortylickens]

NASA makes it look easy because they have the smartest people on the planet working for them.

 

[SMOGZINN]

If you were outside our system's sphere of influence, you wouldn't be in a spot that eventually another system would connect with you, but instead be in an orbit that would 'take you along'.

Correct. Our solar system is in orbit around galactic center. If you broke out of solar orbit you would still have that galactic inertia which is quite powerful. And if you left our galaxy you would still be in orbit around the center of mass of our local galactic cluster.

 

[HarvardAce]

It seems like it's nearly impossible to do X-wing style flying around, stopping, speeding up, etc. Everything takes an enormous amount of fuel.

Relative to another object in a similar orbit, you do have some control, albeit not quite the same level as you see in a sci-fi movie. Stunts/maneuvers performed in atmosphere by planes can exceed 8 G's [1]. In order to pull a similar maneuver in deep space, you would need rockets with a TWR (thrust-to-weight) ratio of 8. Usually, engines designed to maneuver in space (e.g. RCS thrusters) have an extremely low TWR, because they are more efficient and easier to control, and you can make small movements over long periods of time.

 

[Revolution 11]

Relative to another object in a similar orbit, you do have some control, albeit not quite the same level as you see in a sci-fi movie. Stunts/maneuvers performed in atmosphere by planes can exceed 8 G's [1]. In order to pull a similar maneuver in deep space, you would need rockets with a TWR (thrust-to-weight) ratio of 8. Usually, engines designed to maneuver in space (e.g. RCS thrusters) have an extremely low TWR, because they are more efficient and easier to control, and you can make small movements over long periods of time.

That is not a good analogy. Just because your TWR is similar does not mean much. Planes use wing surfaces to generate lift, which plays a very big role in flight and maneuvers. Air friction also plays a big role in limiting inertia.