What does it Take To Deorbit A Moon In Kerbal Space Program
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- เผยแพร่เมื่อ 8 ก.ย. 2024
- No... you can't deorbit moons in stock kerbal space program, the planets and moons are all on rails, but I did some number crunching to figure out what it would need.
Warning: Big Numbers Ahead
Deorbiting a moon is easy, all you need is Majora's Mask
yes
In a simple calculation of amount of force used, Majora's mask might just be the strongest weapon in the Zelda universe.
lol
Eventually, the power output of an angry Cucco will defeat even the moon
+Josh Peterka No, that would be an angry Cuoco
Yes, if the rocket exhaust velocity is comparable to the escape velocity then the thrust is lost.
The Moon now has more atmosphere than it did in the 1950's because the various spacecraft that have visited the moon have added some gas.
I have a degree in physics, and I spent 5 years doing postgraduate research in Astrophysics.
That was however a decade ago, I'm no longer a professional physicist, but I still know enough to speak with some authority.
Amazing
In real life capture is a 3 body process, so, 2 asteroids interact near a planet, once gets captured and the other gets kicked off and escapes the planet's influence.
2:18 "realistically you're gonna want a few million engines on there"
oh the irony
And the strongest engine
@@CUBETechie Not the strongest, the most efficient
@@alex95sang52 I disagree, you'd want the strongest engine per m^2
@@Alex-kh8zj yup
@@the10thdimension 6 years ago
"I'm Scott Manley, fly safe" - But I don't know how to fly a safe...
moar boosters is all it takes
you predicted it
@@Superjump100 I like to think this comment is what sparked the idea.
Fly Safe is the rocket from KSP2
Realistically, you're gonna want a few million engines on there....
Your definition of realistically is epic...
You know, this is why I love math. We can think about completely, totally absurd ideas. And then, after a bunch of engineering advancements, realize those ideas are no longer completely insane and build things like, say, an A380.
Or a Saturn V. Or a B-2.
TrumpeterOnFire
dat Saturn V dou
TrumpeterOnFire Or Kerbals.... :/
Astronomy thinks big
Mathematics thinks bigger
I hate math
What will it take for future engineers to prevent our real life Moon from eventually flying off into Space?
All we need is to push it's orbit 3cm closer to Earth each year, to counter it's current expanding orbital radius.
+Rafael Rabinovich most of the current altitude gain is driven by the earth's oceans, in a billion years it's expected those will be dry and the moon will remain in orbit until the sun dies.
I'm not sure if that's good news or bad news .
Unfortunately by that point it will already be too far away for solar eclipses
Not really good or bad, considering that by then humans will have either died or moved out long before
We could increase it's mass by constructing buildings out of mined asteroids on it. Using earth material would only serve to transfer the mass within our binary orbit. A mass increase of one of the objects in a binary orbit brings the orbit "closer".
I realize this video is old, but here's a thought Scott. Did you take into account the density of the fuel in your calculations? The engines aren't just pushing the moon, they have to move all that fuel as well.
and the rest of the rocket parts
What if the fuel is in orbit and being transferred with a flexible tube?
Howling Din
this is an ambition that I like instantly
this was my 1. concern
+Howling Din The fuel in orbit would be part of the moon's system. You would have to adjust its momentum in any case to keep it near the moon. TANSTAAFL here as well.
I thought I read "How to Detroit a moon"
That's like one of the worse things I can think of to do to the moon
I can't resist an extremely inflamatory comment; Let the US government manage if for a century.
Donald Clinton 2020
Donald Clinton 2020 me to
Just move all the Ice Cream Factories to Minmus. You've Detroited the Mun.
Eh what?
Rockets have hugely powerful turbopumps that push the limits of mechanics? Don't those qualify as moving parts?
Black holes have no upper limit on how much mass they can suck in. There is a problem with how quickly they can suck matter in, if you dump too much matter into black holes at a time it squirts some back out before it reaches the event horizon.
19 Million years? So you are saying that it CAN be done! >:D
No. He explicitly said it's not possible in the very beginning
Fried Keenan Why you got to give me no love, maan... where is the lovin'? Why you givin' me da stink-eye? Da cold-shoulda'? Why... huh? Why?
+Fried Keenan Fuck you.
@@richietkd11 hello person 4 years ago… simpler times
@@schizophil1 I don't even remember writing that lol
Actually, as a black hole's mass goes up the event horizon radius increases linearly, but the volume goes up by the cube of the radius.
So, as you throw more and more matter into a black hole its effective density (based on the event horizon) goes down. Black holes that are billions of solar masses would have a density roughly equivalent to that of air.
Matt Lowne: I de-orbited a magic asteroid today!
Scott Manley: Hold my beer...
golden
Look at Lodgard's face from 3:04 to 3:20
Дани Ласаль Poor Lodgard.
Дани Ласаль I LOL'd
Дани Ласаль R.I.P Lodgard.
+TinchoX Im quite sure Jeb would had a smiling face :)
Дани Ласаль Robbaz, "For the Fallen" - Kevin Macleod
Relax, it's only rocket science.
You don't need much CPU to move the moons off rails.
Scott, you're my new kerbal hero! your tutorials are both fun and educational! and it made my KSP experience tripple aswesome!
"The densest element we know is awesome" - YT subtitles
**deorbits kerbin**
HAPPY END OF THE WORLD
_(brought to you by danny and hyperedit)_
"Realistically you would need about a few million engines on there" realistically
i bet danny2462 could find a way to glitch the mun out of orbit
+Goggles Tigerkhan by using 10000 mammoths and throwing kerbals in their exausts
+waleed khalid Or planet destroyer-ing it, like he did in Special Agent Kirrim on Duty.
Just another TH-cam channel
yea the spear thingy :D
You missed something:
To deorbit a moon, you would need a shitload of fuel. However, this fuel isn't just present there - it has mass of it's own. In fact, in order to move a moon using fuel, you would have to move the whole system of that moon, fuel, fuel tanks and engines - all adding up to whole mass counter. That means you would need MUCH more fuel to move the moon AND itself, along with tanks and engines, and adding a single engine would mean adding more fuel, because engines, of course, have mass, too.
There is another thing, however. By adding so much shit onto the moon, you would greatly increase it's mass, therefore it's gravity. It may be even enough to cancel the orbit and make the moon crash straight into the planet! Who knows? Calculations have to be done.
the weight of the fuel would be negligible compared to the satelight
It may be much less, but definitely not negligible - still thousands and thousands of tons. I'd do calculations, even, but I'm too lazy to do that.
Though you still won't need as much as he mentioned. He said that he would want to "deorbit" by changing the velocity of the moon to 0. You don't need to do that in order to consider a moon being deorbited.
Medhusalem Problems of definitions. Of course it depends on the body that the moon orbits around, but decreasing velocity to zero is a fool-proof way to deorbit something - say, if both objects are just physical points with zero volume.
How did those calculations come out
1:26
cough infinite fuel cough
Elvis van Voorst *cough* Still millions of years. You would have to be VEEEERY bored to do that.
*cough*
yeah youre right
Cough infinite thrust cough
@@Thinnestmeteor cough cheat the thrust to an insane level cough
Dies
"nothing you can do will adjust their orbit in any way whatsoever."
Unless you install HyperEdit.
This needs to be a feature
Look, just change the gravitational constant of the universe. It's simple...
3:17 the look on that kerbals face! priceless!
3:17
Would be fun to Push the moon near Kerban. You know, Like a Super Villain.
They way Scott says "moon" is litteraly the way i always imagined the kerbals saying "mun". Way to go Scott, made my day ^^
I vaguely remember a science-fiction book I read where a moon of Jupiter had massive metal coils built around it, generating electricity from the Jupiters magnetosphere and slowly de-orbiting the moon in the process. Would that be feasible?
It'd be /possible/. Building coils the size of moons is no where near feasible today. We can barely get the funding to launch small probes to mars.
You sir, are a numberphile. And it's awesome!
As an engineer and a mathematician I really enjoy the fact you bother to check the maths within the game. Keep it up!
Pretty cool!
I wonder if a more practical approach to deorbiting a massive body would be to redirect the path of a similar object so as to collide in a planet-ward direction.
Fly as you wish!
"realistically you want a few million engines on here"
You don’t need that delta v, gravity will do it for you. To de orbit on earth you don’t need to Mach the 8km/s delta V . Even so you numbers will be off by a constant (quadratic on v, but just a number) and your conclusions remain. This is one of the best space channels
Hey Scott, can you do a video about what it would take for planets/moons to orbit around YOUR spacecraft? That would be really cool!
Scott Manley: You'd need 276,785,714,285 fuel tanks!
Stratzenblitz: So... it's do-able...
Of course you can de-orbit a moon, haven't you seen "space 1999" ! dammit
Yes I'm joking.
+Caloss2 “TH-cam” Channel But if you want to de-orbit a moon rightly, you better throw a pommel at it.
+Jugde S I'm Brazillian And I love my country it is the best no corruption 10/10 IGN
Jugde S didn't paid they didn't have Money for it
Just move an asteroid to impact the moon from the prograde direction.
I am sure someone else must have mentioned this, but it does seem to be the most realistic way to change the orbit of a large body. Of course, you still have to move the asteroid but if you find ones that are already moving close to your target the delta-v to direct them where you want is in the realm of possibility and because the asteroid already has a lot of kinetic energy the delta-v to the moon can be substantial.
This gets featured quite heavily in sci-fi where swarms of ion propelled drones redirect small asteroids to do things like increase the spin of mars to generate a magnetic field or add more water to the surface.
Scott, you're a clever guy - I really enjoy your vids - high five, Buddy!
I DID IT! I got an E class asteroid into kerbin orbit, I took a giant craft, with an MK 1 cockpit, a crap ton of fuel (frequent resupply missions) and 1000 Nerv engines, I then let it run for a couple months and sent resupply mission daily, after 6 months, it finally reached a suborbital velocity, I re-entered it and landed it, then I used a giant crane craft to set it on a pedestal next to the KSC
So you can't deorbit a moon in the game because of game mechanics, but it would be possible in real life yes? In theory at least. If a moon was hit by a rouge planet or a huge comet/asteroid from the right angle, wouldn't that possibly deorbit the moon? Even if it shatters the moon, the force might be enough to slow down the pieces enough for them to rain down on the planet.
According to my physics class, if something shatters mid-flight, all the pieces will spread out, but if you averaged their distances and masses, the center of mass would still be on the same trajectory. Some pieces might get thrown off track enough to enter the atmosphere or become ejected, but the majority of them will remain in orbit. For something as large as the moon, they would probably eventually come back together due to gravity!
But if a moon ran into something of rougly equal mass in a head on collision, wouldn't that slow it down to near standstill? I agree that most impacts would leave what was left of the moon in orbit and it would probably pull itself back into shape eventually. Since orbit needs velocity, slowing an object down puts it in a lower orbit. If a celestial body had no velocity, then the strongest force of gravity (In a moons case, the planet it used to orbit) would just pull the object in a straight line.
I agree that this is an extremely unlikely scenario, but it is a big universe and it is not impossible that something like this has happened or will happen.
An impact from a large body on a moon could alter the mass of the moon significantly which would, if not totally deorbit it, then at least change its orbit distance.
Yes it is unlikely, but you're right. If something with equal kinetic energy (could be something less massive but moving much quicker, or equal mass and speed) hit the moon from the opposite direction, it would stop in it's tracks. It might break up a little bit, but some LARGE pieces would fall straight down to earth and would likely destroy all life, if not the entire planet. I could imagine something of that size striking the earth could break up the crust and smash it down into the mantle or something crazy like that!!
Let's hope that never happens. And if it does, lets hope it happens to some other planet with no life on it, but still close enough for us to observe.
Though any kind of impact on the moon would slightly alter the orbit by adding more mass, or making a small change in velocity. I think.
Just like everytime a meteor strikes earth, it adds to the earths mass and gravitational pull by a very small ammount.
SHould we just fold that under one of newtons laws : for every action there is a oppsidte and equal reaction. Considdering the materials of the object would stay togethere that is exactly how it would happend(forces canceling eachother out. But ofc , it will not. It will acctullay be more like having 2 water ballons thrown at each other. If you managed to do it perfectly.
TH-cam really wanted me to watch this again 😁 (recommended list) so I had to watch again, you should try again but mod in a silly amount of rockets on it
BUT won't the gas from your engines eventually FALL back on the moon, cancelling its work?
No, because the gas particles are expelled at a higher speed than the local escape velocity, which means they will fly away into space.
Damn you Isaac Newton!
That logic, I don't think it logics what you think it logics.
I'll see myself out.
Get wrecked
tim n
Actually, that probably would be a significant issue if you were trying to deorbit Kerbin, Eve, Laythe, or Jool, given that the atmosphere's would reduce the exhaust velocity of the rockets to the point where they wouldn't be able to escape the planet.
I love how fot the sake of the vid, Scott flew some tanks to Gilly to run the into the ground
I absolutely love the fuel mass to moon mass ratio.
Does your calculation take into account the required additional force to move the mass of the fuel as well?
Go and watch my science video about the reason why specific impulse is measured in seconds. You'll understand.
MY BRAIN!
It can't handle this much... Math... Must... Get... Cyanide...
GodOfTheeGames He didn't show you the math. Only the results.
GodOfTheeGames or Soviet womble
And Hapiness
Ok, now you are describing how to build Panama channel utilizing Pickaxe. Or how to move a supertanker utilizing beasts of burden. A very useful exercise.
Your accent is awesome, sir.
this is amazing. My issue is, I don't want to halt the forward momentum, I just want to push them in towards the planet which could be done by pushing in on the outside of the orbit rather than the front.
Challenge accepted
Did you do it?
Really? Did you?
Based on those numbers, though, it COULD be possible if they were to include an engine that was basically a miniature nuclear weapon with its blast zone somehow reduced to a tiny force trajectory... the Tsar Bomb produced 210 petajoules (that's QUADRILLIONS of Newtons per meter) with a weight of only 27,000 kg (admittedly packed into a tight 8 X 2 meter missile)
If that energy could be focused into a single lateral direction, it would be TOTALLY plausible to de-orbit a minor celestial body like a moon.
But I can use hyperedit to move the moon D:
hyperedit was probably released after the video
Thank you for saying at the beggining that is not possible, and not clickbaiting us for 10 minutes. Much respects to you sir !
I dont get it why his videos keep apearing on the video list..
I dont even like Kerbal Space Program!?
Because youtube analyzes the data and it see that people that like MInecraft and Garry's Mod also tend to like kerbal space program. I just wish they'd make videos appear for my subscribers regularly...
Or maybe they know I have a whole pile of NWA in my record collection.
Scott Manley I like those two things and found your channel because of it. And I started watching your Interstellar Quest. Only 18 parts in now, but its great. But watching it, I had the thought of what it'd take to move a moon which lead me to THIS video.
Anallogic Welcome to TH-cam, where some neckbeard in a basement tells you what to watch. Download Adblocker Plus, and enjoy the internet again.
Slyguy threeonetwonine
Lol yeah, i commented this some time ago and ive been using adblocker ever since. Coincidence? yes probably.
Videoooo
The best thing about Adblocker is all the doom and gloom sayers who say its killing the internet. All of them from people in advertising. What they are saying is AdBlocker is killing "their" internet. Its bringing "our" internet back to life.
Thank you for not being a clickbaity person and saying that you cant deorbit the moon at the start of the video. You have my respect.
Can you just use the infinity stones and be done with it. Easy.
Been nearly 9 years. Still burning. I think I've shaved off 0.000001m/s.
Challenge acepted
Gas rockets can't move any massive object and here's why:
Unless you get the exhaust moving faster than escape velocity it will just return to form an atmosphere and give no net thrust.
What's worse is this atmosphere will then further block the rocket exhaust from escaping.
And to top it off, even if it is travelling faster than escape velocity when it exits the nozzle, it's a gas and will expand. As it expands it will no longer be heading straight away from the moon, making it even easier to be recaptured by the gravity well.
or u could put infinite fuel on
but putting all that quantity of engines would take alot of disk space.
Worth consider in ksp 2, shouldnt be dificult to add objects like moons (and tires or metal rods) that dont explode.. at all, maybe a step beyond would be to add debris into destroyed objects and maybe some matter annihilation in nuclar explosions.
Or you can use 1 mod and a few mouse clicks.
Because you can put the Mun in orbit wherever you want to.
yeah
you can bring few ISRU converters with several drills (per each engine) and simply mine the fuel you'll need :)
i know planets are 'on rails' and game-wise its not possible to move them but still.... easier than moving all those trillions of fuel tanks.
Don't gravity assist maneuvers reduce the moon's velocity?
Love at the end of the video he lightly taps the moon and just disintegrated
You can actually deorbit a moon. I don't know how but some guy on youtube did it while messing around with a meteor
Pretty sure it was Danny, and it was a glitch.
Link?
You could use an extractor and a converter to replenish your fuel as you worked. For that matter, if you packed along enough extractors and converters, you could use a Mammoth or two instead of a NERV, since you can convert ore into oxidizer and liquid fuel at the same time. Use the Mun itself as your fuel tank! Of course, that still leaves the problem of "it's on rails". Mod anyone?
Why does it show ads for Kerbal before the vid? =/
A kerbal ad? Must be a channel trailer for some other channel.
Oh Boy!! A channel with lots of Kerbal? I should sub to that channel =D
This sounds like a project for SWDennis. He tends to like using mods that let him scale up part sizes by ridiculous factors. Using those mods (and whatever joint modifying mods he uses) you could probably make a ridiculous enough engine to de-orbit a moon if it weren't on rails.
First 20 seconds in and i find out the truth, time to watch something else
We also could just put some Drills and converters onto the planet.... would also make it easier to Deorbit due to the mass sinking proportional to the produced fuel...
What if instead of pushing it we just detonated a huge bomb next to it or potentially launched an astroid at it, that would easily deorbit it right?
Think about how much force was just explained in the vid. Now imagine all that force hitting all at once. Sure, you could knock the moon out of orbit. You'd also obliterate most of it and shatter what remained.
Serithi I never said I think while writing these comments. XD
Serithi Heres the thing though. Yes you might blow up the moon with that much force at once, but other than that it wouldn't actually do anything else. All of the remaining pieces of the moon would probably continue to float around in a relatively unaltered orbit. That's just how the physics work out.
Stuart Smith that's not how the maths workout at all
Patrick Sparks That is how it works but if i need to explain i will.
The amount of force our mythical explosion has is incomprehensible and since moons aren't exactly designed to withstand such forces (after all they're mostly composed of rocks so its not that tough) you will break the moon apart before the explosion can apply all of its force. Picture this: You swing a baseball bat at a pane of glass. The glass breaks and the shards go flying. If you hit the glass 10X harder than that the shards don't really go much farther because most of the force of the swing is wasted due to the glass breaking. It's the same thing with our explosion. Most of the force is wasted because it doesn't hit anything once the moon starts breaking. Making the explosion more powerful won't really help because you will break the moon even more. If the moon were indestructible you might be able to make it work but otherwise, no way.
If you still want to argue I will be happy to debate with you.
With the updates we have today, you can drill the moon for fuel to deorbit it while at the same time having your engines active.
Alt F12 is your friend
***** In case you didn't know, Alt+f12 in KSP brings up the debug menu where you can do things like hack gravity (Kinda disables it), infinite fuel, unbreakable parts, unbreakable joints and such.
Sindri Karl does alt f12 work in demo?
Sindri Karl YOU WONDERFUL PERSON
***** im not mexican
***** and apparently you got five because your conclusion was wrong, so who's the stupid one?
You pushed gilly! The height got decreased by 1 meter at 2:58!
hey uuuh scott, what if you wanted to deorbit it the other way? you know, make it leave the sphere of influence of it's parent body
Its not possible since all the planets and moons in KSP are on "rails".
I know that, I'm wondering on the math, like, even though he showed you couldn't make moons crash into the surface of the planet, he did explain the math if it were possible.
***** Well with our own moon it is already happening.
rainick Yeah but it will never actually leaves earth's SOI. If the universe exists for millions of more years it will balance out . I don't feel like explaining it since I would make myself look silly with big terms, but just look up "will the moon leave earth" or something like that
XxJaguar22 inverse square law, mane. the further the moon gets from earth, the weaker the gravitational attraction the earth has on the moon gets.
not to mention the fact that unless the fuel particles are exiting your rocket at >escape velocity, they are going to impart a net velocity change of zero to the moon youre trying to deorbit. because they will go up, and then just come back down again.
similar to if you were to throw a baseball attached to a rubber band while standing on ice skates. when you throw it you will start moving backwards, but when it reaches the end of the rubber band and springs back towards you, you will start travelling forwards, then when it comes back to you you will stop moving.
so you probably couldnt achieve this with NERVA engines. you'd need something with higher thrust, so the numbers become even more ridiculous
the title makes me uncomfortable, kind of too click baity for me.
"does" could be replaced with "would"
voice of reason 'does' implies it's possible, 'would' implies it's not.
Zestea that is exactly my point.
As it is not possible to do it in the game.
DETH2 DaGOOG good day to you as well :).
you make me uncomfortable
this was my introduction to KSP and your channel, more than 4 years ago
Can you deorbit asteroids...?
you can
i remember making an engine mod and made it work no fuel, i tried to push Kerbin out of the way with an Engine that has 1 times the weight of the planet and it could fly up because it had 2x the power! so starting with it upside down on the pad, when i turned it on, it did not push the planet and that is how i figured out it was on rails! tho when i removed the weight and not the speed, in the inverted position, it just teleported out the planed into black! and the game was all bugged and no menu! the speed started with the number 4 but had to many numbers to display! cool and freaky experience!
Fly safe? But that's boring.
yeah
Scott, try landing on Gilly with 3 Mainsails, and 4500 kiloNewtons of thrust. Try to make the rest of the ship as light as possible, and you must use the engines in "Bursts" so you use action groups to turn on the engines and keep it on full throttle. You must also use mainsails for interplanetary injection and return. dropping stages are okay
Or you could use hyperedit
Did this once!!
Thank you for showing this vid to all of us because this shows it is impossible for man to have ever landed on the moon if as soon as our feet touch the moon it implodes!!!
We have found the truth on youtube!!!!
Your wrong Scott when you said you can do nothing to a moons orbit, actually with hyper edit you can.
hes talking about with rockets... those sort of mods are obvious
but still, celestial bodies go through each other with HyperEdit, even though you can make Jool orbit Gilly.
If physics in KSP would allow. I might take diffrent aproach to deorbiot any plane/moon/asteroid. Build something heavy and big enough. Put that in right orbit to pull right direction. I think that would be most practical since all bodies are rotating which make it harder to time your burns.
You don't need to kill the velocity completely to de-orbit an object. So all your math is useless (sorry but not sorry)
All he'd really have to do is bring an object close to the moon with enough mass to create the gravity required to draw the moon toward the planet enough to destabilise its orbit. Like a few trillion fuel tanks.
kajidono but rocket parts dont create a gravitstional force sadly
IRL it does, but not in game, i dont think
Jupiter GD but they do create mass which is how gravity works
the bigger mass= the bigger gravitational force
Not in the game, which is what they were talking about, you morons.
3:07... I think I heard my laptop start to cry when I watched that part.
Ion engines are the most efficient, but also have some of the lowest thrust possible. So they suck for getting out of orbit, basically can't be done, but are great in deep space over long stretches of time.
If we are going to talk real physics here, it's still not possible with ANY amount of fuel, as the exhaust gasses will remain in a moon's atmosphere, and only contribute to it's mass. An ion engine would probably work because the ion plasma escapes at a fraction of the speed of light. This is why they have such high specific energy. But they are very low thrust.
The reason it works with an asteroid is that the asteroid's mass is insignificant, and the exhaust gasses readily escape any interaction with the asteroid.
Although on a moon, the exhaust gases do escape at a rapid velocity, and you'd think they would shoot out into space beyond escape velocity, this isn't true. They are, afterall, gases, and a gas has all sorts of characteristics like molecular interactions, bonding, and PRESSURE. The escaping gasses will form a slow moving cloud and eventually envelope the moon. Shooting a rocket off will quickly need to move it's own exhaust ploom off the moon as well. The ploom will begin pushing back on the moon with an equal force. Using a rocket on a body large enough to have just a slight atmosphere would be no more effective than pushing on the handrail of a boat, while standing on that same boat.
It'd be kinda scary if you could, cuz one glitch could send your planets flying away from the sun.
Deorbit kerbin: that way there will be no problem of delivering all that stuff, since it's already at it's final destination ))
Let us simply do what Wise Patrick once said. "Push it somewhere else!"
This was the first Scott mainly video I ever watched, and I didn’t know it was about ksp. I decided to watch it anyways because it was interesting, which led up to my obsession with Kerbal Space Program!