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What KSP has taught me to be annoyed at


KBMODIGITY

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Pretty sure in that startrek example the enterprise was holding itself up, not orbiting. It wasn't moving fast enough to remain geostationary at that altitude.

Yes but the fastest trip between earth and the moon was the New Horizins Pluto probe, which still took over 8 hours of powered flight. It would have taken them much more than 10 minutes to fall to Earth.

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KSP will ruin sci-fi for you, it's true. Unless it's intentionally campy sci-fi like Red Dwarf or Hitchhiker's Guide to the Galaxy. Those can get away with the inaccuracies because they poke fun at them.

Wowowowowowowooah.... lets not talk crazy here...

What do you mean the Hitchhikers Guide to the galaxy is science fiction? ;)

But to keep at the Topic:

KSP has taught me almost everything I know of orbital mechanics that I know today.

But what this ruins is, that I now know that almost every Space-Simulation is crap without newtonian physics and stationary planets like in Freelancer.

And the worst thing is, that I probably should have started in a different carreer :)

Edited by MalfunctionM1Ke
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This sort of vertical climb thing is portrayed over and over in movies

Hooboy. That and its corollary -- ships which fall out of orbit straight down. Even if they had zeroed out their orbital velocity first (which they never do) the planet is still rotating. The new Doctor Who is infamous for this. TARDIS turns off its anti-grav and immediately plummets straight down at high velocity.

As for Gravity, I found Sandra Bullock's damsel-in-distress character more annoying than the iffy orbital mechanics.

Aye. This.

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The Star Trek episode "Hide and Q" has the Enterprise trying to keep an asteroid in a decaying orbit from impacting a planet by applying thrust at "perigee". I said to myself, "No wonder they're having problems!"

To be fair they never said if they were applying prograde or retrograde thrust, and it's sort of an unwritten rule in the Star Trek universe that everything must be done in the most energy inefficient way possible. You know, like assembling a cup of tea, cup included, out of raw energy, instead of just sticking a cup of water next to the reactor core to heat up. The latter would be the Kerbal way. :D

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To be fair they never said if they were applying prograde or retrograde thrust, and it's sort of an unwritten rule in the Star Trek universe that everything must be done in the most energy inefficient way possible. You know, like assembling a cup of tea, cup included, out of raw energy, instead of just sticking a cup of water next to the reactor core to heat up. The latter would be the Kerbal way. :D

My point was that they are applying thrust at the wrong point of the orbit. If you want to adjust your periapsis, thrust at apoapsis. With them applying thrust at periapsis, all they were doing was mucking with the apoapsis. Good thing they had Q around to make it all better at the end of the episode! :D

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I'm not sure if you would learn this in KSP, but what bothered me the most about Gravity was when the Sandra character used explosive decompression to launch herself towards a space station?

She should have had every bone broken when flattened against the door in the time it took to fully open.

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My point was that they are applying thrust at the wrong point of the orbit. If you want to adjust your periapsis, thrust at apoapsis. With them applying thrust at periapsis, all they were doing was mucking with the apoapsis. Good thing they had Q around to make it all better at the end of the episode! :D
If it's in a "decaying orbit" there's every chance the apogee is too low as well. A big burn at perigee would be needed to kick the apogee back up, then another burn at apogee - or indeed make the perigee burn so big that it puts the asteroid on an escape trajectory.
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Wonderous no-one mentioned the reentry on the end of the movie.

A ship so heavely damaged going into the atmosphere in a wrong angle, so heavy beaten up and

still could make such a soft near perfect water landing, and get out and swin to the coast, and WALK normally after beeing in space a while.

So funny of all the modern movies, only an handfull have the mechanics right..

Most amazingly, i was watching a few feeks ago 2001 a Space Odessy again, for a movie made before we even went to the moon, that movie was

pretty correct compared to most modern SciFi movies on its mechanics as well, in an era space was still in its infancy state. (still hard to watch it to the end without falling asleep :-) )

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I find myself shouting at VTOLS in movies; you know the really large ones that come in with a stylish 180 spin as they come to a perfect hover with apparently nothing acting to cancel their lateral velocity. And then they just hang there, on tiny little engines that could barely keep a weasel aloft!

and of-course things that take off and reach orbit by going straight up, maddening!

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As far as inaccuracies go, when you have ships capable of FTL travel, do you really think they are worried about deltaV? If they can go FTL, they also have an engine that has light years of deltaV and the shields/hull to compensate for whatever atmospheric entry profile they want.

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Also with that kind of power, cancelling a little thing like momentum becomes as easy as walking. So wild maneuvers like what we see in BSG, star wars, star trek, or any number of badly made sci fi flicks becomes possible. Its possible to pull this off in KSP with the right parts.

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After KSP I just can't stand starfighter combat. Any movie that has little fighters flying around at full burn, banking into turns, and generally pretending that their swimming in an atmosphere bugs the hell out of me. It's especially annoying when one ship is chasing another - the lead ship could spin around and fire back at them in reality, but in the movies they just keep running. Not to mention people forgetting about the third dimension, or flying into a hanger head first with their engines still burning - how are they slowing down?

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After KSP I just can't stand starfighter combat. Any movie that has little fighters flying around at full burn, banking into turns, and generally pretending that their swimming in an atmosphere bugs the hell out of me. It's especially annoying when one ship is chasing another - the lead ship could spin around and fire back at them in reality, but in the movies they just keep running. Not to mention people forgetting about the third dimension, or flying into a hanger head first with their engines still burning - how are they slowing down?

You guys should all watch Babylon 5. You'd be proud.

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Also with that kind of power, cancelling a little thing like momentum becomes as easy as walking. So wild maneuvers like what we see in BSG, star wars, star trek, or any number of badly made sci fi flicks becomes possible. Its possible to pull this off in KSP with the right parts.

I appreciated the minor touches of the BSG remake for exactly this reason. They didn't get everything perfect, but they are one of the few shows to decouple linear and angular momentum for a majority of dogfight maneuvers. They also made some effort--again, not perfect, but appreciable--to minimize the whole sound-in-space paradox.

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Wow. I forgot I started this thread. Now I see 8 pages worth of replies. Thanks all. Thought this would be a thread that got quickly buried in the forum somewhere. I got a few LOL's out of some of the responses to people. Impossible not to love this community at least on the official forums. Steam forums are another thing.

Most importantly, it is true. NOONE WANTS TO SEE SANDRA BULLOCK IN A DIAPER!!!!! :P (That part of the movie I'm glad they got wrong)

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I'm going to do a real newbie thing here and just read the first two pages and comment on something from the first post that may have been suggested in the last couple of pages but...

Regarding Gravity: I've been trying to get my head around its inaccuracies and looked at it from the point of view of 'are the inaccuracies deliberate'.

There are several things that annoyed me with it:

1) When Sandra and George are travelling from one SS to another they burn prograde to the target at full pelt to reach it. We all know from playing ksp that you need to burn prograde to your orbit to raise it higher in order to allow the target to catch up to you. I believe the reason why George did this was because time was more important than delta-v - he needed to get them both to the next station asap - burning away from the target would bring them to the station too late and they'll die anyway - at the point where they are rendezvousing with target George does mention that he's out of fuel (using it all up on the way there). If you want to get to a target using the least amount of delta-v - do a hoffman transfer. If you need to get to the target asap you thrust full pelt at the thing and hope you can grab hold of something on the station along the way.

2) Sandra's decent back to Earth. I think George says at one point to just point the capsule to the earth and thrust - its not rocket science. We all know you need to point your ship at your retrograde marker and burn to lower your orbit. Again this will take longer. So he's right - it isn't rocket science but thats what he was getting at - Sandra's character is just a visitor (a tourist you might say) - so she doesn't know much about orbital mechanics like we do - shes a mission specialist and have a large crew around her to deal with all the spacey stuff. Teaching her about basic orbital mechanics, how to control the rcs on a capsule, point it in the correct direction on a navball, make sure she gets this exact so she doesn't come in too fast or too slow and burn up or skip out of the atmosphere, teach basic Japanese so she can read the controls - ain't no-one got time for that! Tell her to point at that big blue planet in front of her and thrust like crazy and that should give her enough radial momentum to get her in to the atmosphere and let drag do the rest of the work.

3) And lastly the bit that bothered you with George holding on by her boot. If they are in a stable orbit and he's lower in the orbit by a couple of feet below her then a gentle tug of the rope will bring him up towards her to save him. But, they aren't in a stable orbit. Iirc they are tethered to a station that has been ripped to shreds. There are still probably small pieces of debris (microscopic) smacking in to the station passing on their momentum on to the craft, there is probably all manner of gasses venting from the rcs, oxygen, water tanks like a sieve so the station is probably accelerating relative to it current vector which is causing drag on sandra and george - I had to do a similar thing last night using KAS to lift a stranded buggy off of mun - it was causing the rocket to buck around like crazy while thrusting - in the end I had to give it a large enough nudge with thrust to bring it in to an elliptic and then dethether it so I can bring the rocket back to some kind of control.

I can't think of anything else regarding Gravity and I think they got so much other stuff so right on it that these things can probably be forgiven anyway.

What really annoys me now that I've been playing KSP for a year.

- How hard we make it out IRL to colonise the solar system. Playing KSP I know the hardest part of any mission is the launch - getting enough payload in to low earth orbit. Anything after that is pretty easy. We have docking down with experience from the ISS we can do it with our eyes closed. We can dance with the planet orbits with gravity assists and aerobreaking with every satellite and probe we've sent up - just watching what Cassini is doing around Saturn is just amazing as it skirts around each moon with ease. And yet - we haven't got a colony on the moon or mars - we aren't flying spaceplanes through Venus or mining asteriods and it annoys me - it annoys me so much that all we need to do is get the payload off of the earth and then send a crew up like we do for the ISS and we're good to go. The solar system is waiting for us and we're just sitting on our front porch moping.

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.

1) and 2)

The question remains whether the "jet pack"/capsule has enough dV for such an inefficient maneuver, but I think they deliberately omitted things to 1. keep the drama going and 2. get not to sciency in a field that is not necessarily general knowledge.

3)

Not going to comment on this again. :cool:

IRL launching stuff is the easier part. It is keeping the people in space alive and healthy for months (years, if we are talking mining asteroids) where the problems start.

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