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Electric Rockets (no mods) help


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I need some help planning how to make a 100% electric engine with NO mods. 
 
(cost? No matter! I’m using science mode)

if you have ideas that you have not tested, pls say they are not tested in your post. 
if the ARE tested pls say that too. 

I want this rocket to be one stage, lite, and 100% electric! (Xenón gas is required IK, but if I do 5-10 x8 clicks I’ll be fine.)

once again, this is a NO mod wall. 
 

any help will be great, anyone can use ideas on this from this wall as well. (I’m not a idea hog, besides it’s a community wall)

 

please be nice, no hate posts (including: racist, sexist, age hate, or what ever else)

 

 

if you have a video l, post the url in your post as well.

thank you for all the help 

 

CAUTION!! ANY IDEAS POSTED ARE FOREVER OUT THERE FOR ALL TO SEE, KEEP YOUR PRIVATE IDEAS AND SECRETS TO YOUR SELF

 

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This question has been moved to the Gameplay Questions Subforum.

And there's no need to restate our Forum Rules.   If a post doesn't meet our forum standards, it can be reported and the moderators will deal with it. 

Welcome to the forums @MrWookie2U!

3 minutes ago, MrWookie2U said:

I want this rocket to be one stage, lite, and 100% electric! (Xenón gas is required IK, but if I do 5-10 x8 clicks I’ll be fine.)

I don't think this is easily done in a stock game.   The Ion engines don't have the thrust to get to Orbit, although it's been years since I've tried for that very reason. 

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I never said it would be easy, but I want to create a rocket in vanilla KSP (vanilla the term for no mods in KSP, it is for “Minecraft” if it’s not the term, what is?). 
 
non modded KSP uses parts that have IRL counterparts so I’m trying to make an electric rocket for possibly irl use.

 

thanks for the pointer tho, but I don’t expect it to be easy.

 

have a good day sir (or lady if you a girl)

 

ps. Love the smerf reference in your Icon/name XD 

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By electric rockets do you mean the ion engines? They are intended for high efficiency which means they have the extremely weak thrust. Those are harder to fly because the burns take so long. 

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Yes. That is what I ment, I’m thinking of making a small t1 rocket for science purposes to go out into the cosmos. It will be radio and packed with research stuff 

(will have a few versions with different amount of stuff, for cost effectiveness in career mode (if that’s what it’s called)

 

I might try to post it for public use (never done it before, need to figure that part out) but only if it works. I hope it does

 

it will have a solid rocket to get it to space tho. Ion idle just for galactic travel. Why not use the sun, and be “green” in the process. 
 

(Edit: t1 is teir 1 right?)

Edited by MrWookie2U
Added the stuff in the “()”
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16 minutes ago, MrWookie2U said:

Yes. That is what I ment, I’m thinking of making a small t1 rocket for science purposes to go out into the cosmos. It will be radio and packed with research stuff 

You need xenon electric ion drive (around 3200 in vacum, so around 10 times more then chemical reaction). It is somwhere right on techtree on similiar level as nuclear engine.

It do not work (well) in atmosphere, give thrust like hair dryer, is very small and need lot of electric suply but deliver huge amount on dV, just some manouvers takes hours so You burn, then loading electric, then burn again and so on. Manouvers inside planets sphere of influence are quite spiral because of that, but around Sun it is up to scale.

19 minutes ago, MrWookie2U said:

it will have a solid rocket to get it to space tho. Ion idle just for galactic travel. Why not use the sun, and be “green” in the process. 

They are so small that You propably attach it to another rocket (dedicated for moving Kerbal would take 3 such engines to give any reasonable thrust to weight with battery and solar panels).

But way up on SRB is a good idea. But forget about "green" - to get clean xenon You have to burn lot of coal. And amount of xenon limit Your dV any way. It cannot be mined - You need to take it with You.

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46 minutes ago, vv3k70r said:

You need xenon electric ion drive (around 3200 in vacum, so around 10 times more then chemical reaction). It is somwhere right on techtree on similiar level as nuclear engine.

It do not work (well) in atmosphere, give thrust like hair dryer, is very small and need lot of electric suply but deliver huge amount on dV, just some manouvers takes hours so You burn, then loading electric, then burn again and so on. Manouvers inside planets sphere of influence are quite spiral because of that, but around Sun it is up to scale.

They are so small that You propably attach it to another rocket (dedicated for moving Kerbal would take 3 such engines to give any reasonable thrust to weight with battery and solar panels).

But way up on SRB is a good idea. But forget about "green" - to get clean xenon You have to burn lot of coal. And amount of xenon limit Your dV any way. It cannot be mined - You need to take it with You.

Darn. Oh well, back to my space plane idea. 

Still gonna make a space station in Kerban orbit loaded with fuel tanks. 

Wandering why they made “green” or electric engines impossible?

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14 minutes ago, MrWookie2U said:

Darn. Oh well, back to my space plane idea. 

Still gonna make a space station in Kerban orbit loaded with fuel tanks. 

Wandering why they made “green” or electric engines impossible?

because that's how it is in real life. ion engines have extremely low thrust, compensated by them taking very little fuel. but they can only be used in space, where you have no weight, and you can afford to accelerate slowly over several months. that's what the dawn probe did, to orbit two different bodies. in fact, in ksp the ion engine is already much more powerful than its real life counterpart, because you can't make a month long burn in a game. the ion engine has too little thrust to lift itself, so there's really no way.

Ok, technically, i've seen a video of someone making a spaceplane that could go orbital with it. But it used kraken aerodinamics (heat shields angled a certain way are much more efficient than wings, and attaching parts at odd angles and moving them around impossibly with clipping can reduce drag much more than realistically possible, while having a shape that should never be able to fly in the first place) it doesn't really count

anyway, if you want an efficient rocket with electric engines, you just have to send it to orbit with regular means.

finally, i'm not sure i'd qualify electric engines as "green" just because they are electric. Chemical engines exhaust is mostly water, and the chemicals required to make those fuels can all be produced out of fully renewable resources. they can also be found on other celestial bodies with relative ease. on the other hand, xenon is very rare, i'm not sure how much of a stock we have, and it's almost impossible to find out there (unless going to a gas giant, but for obvious reasons it's impractical to mine those). I got much more mileage out of chemical rockets by making new fuel along the way and servicing my spent crafts than i ever could from electric engines. In fact, i got bored of my career when i reached the point where i never needed to launch anything because all my vehicles were completely reusable

Edited by king of nowhere
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42 minutes ago, MrWookie2U said:

Wandering why they made “green” or electric engines impossible?

Because there is nothing like green energy. To move mass in reference to other mass in time You have to get entropy worse. So You can choose to get photons from burning start, or use coal and oxygen from older star that did coal and oxygen cycle and died, or You can use  radioisotops made from corpse of even stranger star that died in more horrific way. Any way - You have to burn the stars and get entropy worser. Low entropy in (like shorter wave radiation, separated coal and oxygen, radioisotops) - heat radiation out (like longer wave radiation, chemical combination of higher entropy, high entropy radioisotop) and so You move things around.

If You would fly away from a planet You have to use some very orginized matter from this planet and throw it away. Like hydrogen and oxygen.

28 minutes ago, king of nowhere said:

(unless going to a gas giant, but for obvious reasons it's impractical to mine those)

Mines look that way:

Top%20ten%20deepest%20open-pit%20mines%2

So we have just to explode gas giant like we explode rocks and get what we want from the asches!^^

We just need sligthly bigge ka-boom to get rid of gasgiant.

Edited by vv3k70r
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If you count DLCs as ‘stock’ then you might be able to combine Breaking Ground’s propellers and motors with ion engines to make a pure electric SSTO, though props have a low top speed and altitude ceiling which is probably not enough for ions to get the rest of the way into space.

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@MrWookie2U If you're fine with having a traditional launcher to place the thing into orbit, ion drive spacecraft are not that hard; the only part that requires real design thought is the power delivery. It basically goes like this:

  • Build the science probe you want to use: probe core, antenna, instruments, batteries. It should be in the 0.625m form factor. Larger ion probes are perfectly possible, but let's keep it simple for now. Make sure you have control authority (the OKTO-2 for example doesn't have reaction wheels).
  • Attach a single inline xenon tank and a single 'Dawn' ion engine. Check the dV reading in vacuum. If it's way more than you'll ever need, axe the inline tank and use two radial xenon tanks instead. But keep a healthy amount of excess dV, because you still have to:
  • Add power production. One Dawn engine consumes roughly 8.75 Ec/s. You have two options for the general power architecture, and each of them has three possible variants in terms of part choices.
  • Option 1: full power delivery. Use this if you're not sure how long your burns are going to be, or if you simply don't want to be limited by your power production. As such, you need to provide a solution that produces the required 8.75 Ec/s at all times, even when the engine is off. That means it's potentially going to be pretty large and heavy, and sitting unused most of the time. But it's worry-free.
  • Option 2: buffer with recharge. In this scenario you would provide only a part of the required 8.75 Ec/s in power production, and additional battery buffer to get you through your burns. Because batteries effectively weigh less than power production equipment, this makes the spacecraft lighter, which increases your TWR and your dV, and makes the required launcher smaller. And since the power production equipment is going to do work even when the engine is off, to refill the batteries, you're getting more value out of your investment. However, this places a hard limit on how long you can run your engine at full power. If you produce 4 Ec/s and have 1000 Ec energy storage, then the engine (plus probe core) will be able to run for 200 seconds. Any burn longer than that will require you to throttle down to less than half thrust - and the ion engine already has anemic thrust to begin with.

As mentioned, you have two options for how you want to produce your power.

The first option are radioisotope thermoelectric generators (RTGs). They have a big upside in that they just work everywhere. Daylight, nighttime, at Moho, at Eeloo, you're going to get exactly the amount of power you designed for, at all times, forever. They also have a big downside in that they are absurdly heavy for each Ec/s you want to produce. A 0.625m sized probe might weigh around 600 kg with the Dawn engine and fuel included; but enough RTGs to actually run the engine at full power would add another 960 kg - increasing the mass of your probe by over 150%. For this reason, RTGs are typically only used with the buffer-and-recharge option. The mass efficiency gap between them and batteries is just so large, it really begs to be used.

The second option are fuel cells. They, too, give you all the power you need, whenever you need it, regardless of location and time. And they are a lot more mass efficient than RTGs. But as a trade-off, they require you to bring liquid fuel and oxidizer along, which they will consume - and once you have consumed it all, you'll be out of power. Additionally, for some unexplained reason, Squad decided to make the small single fuel cell a huge amount worse in both mass and fuel efficiency than the big fuel cell cluster, to the point where it is practically always better to just make your probe a whole lot larger and run multiple ion engines on the much better cell cluster. Which leads to another downside: you really cannot build something small and light that uses fuel cells well. The tank and cell array are going to completely dominate your design. You're almost automatically going to end up with a 1.25m form factor, and can easily go larger. Which is fine if you're trying for some cool crewed space cruiser. But for a quick and efficient science probe, it's utter overkill.

The third option are solar panels. They seemingly have all the upsides: small when folded up, attachable anywhere, mass efficient, good power delivery. Ideal in every way. However, if you're in the shadow of a planet, they're going to be useless. And the way orbital mechanics works, you'll always be in Kerbin's shadow for the majority of a burn that's going to the outer planets (Duna, Dres, Jool, Eeloo). Which means an ion engine spacecraft without sufficient battery buffer is going to struggle to even get on its way. And then there's that thing called the 'inverse square law'. The intensity of sunlight is inversely proportional to the square of the distance from the Sun. So as you're moving away from the Sun, going to the outer planets, your solar panels are going to get weaker and weaker. At Duna, you might still be getting roughly 40%-45% of their rated power; at Jool, you'll barely be getting 4%. Trying to power the hungry electric engine with that is going to be a real challenge. But, do note that this works in reverse, too. Going closer to the Sun, down to Eve, for example, almost doubles the power output, and at Moho your panels are going to be at over six and a half times rated power. Plus, when performing a burn towards the inner planets from Kerbin orbit, you'll always be in daylight.

In summary:

  • RTGs are always going to be using the buffer-and-recharge strategy. Fuel cells are almost always going to end up doing full power delivery. Solar can go either way, depending on the use case.
  • If you're going to the inner planets, always go solar. You can either go for full power delivery here, or deliberately undersize your panels at Kerbin so that they'll be delivering full power for less mass once you're closer to the sun. This works especially well if you can get a bit of an initial push from leftover fuel of your launcher's upper stage.
  • If you're going to Duna, solar is still fine. You can go for full power delivery at Kerbin and bring some extra batteries so you can run buffer-and-recharge at Duna, or deliberately bring twice as much solar power so that you'll still be at full power at Duna. It'll carry a mass penalty, but it's not that bad. Most of the time you're still going to need plenty of batteries anyway, though, because your transfer burn is on Kerbin's night side.
  • If you're going to Dres, full solar power delivery is an exercise in futility. Either go solar buffer-and-recharge, or choose one of the non-solar options.
  • If you're going to Jool or Eeloo, pick a non-solar option. Remember: RTGs are going to be really heavy but compact and endless, while fuel cells are much more mass efficient but physically huge and have limited fuel.
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17 hours ago, MrWookie2U said:

Wandering why they made “green” or electric engines impossible?

Mainly because KSP is supposed to be at least somewhat realistic, and they are, in fact, basically impossible.

Electric engines are, of necessity, extremely low thrust.  That's because they get their thrust by using electric power to accelerate the reaction mass, and it takes huge amounts of power to do that.  Batteries and solar panels produce teeny, tiny amounts of power compared with what you get from burning rocket fuel.  They get very high dV values because they can accelerate their exhaust to extremely high speeds, but they can only do that as a tiny trickle, thus the extraordinarily low thrust.

And even to get that level of efficiency, they have to be in a vacuum, or extremely close to it-- so you'll never be able to use them to launch from the surface.

Launching from the surface of a high-gravity planet (like Earth, or Kerbin) requires high thrust.  If you don't have that, no matter how efficient your engines are, you'll never make it to space.  And high-thrust engines require expenditures of very large amounts of energy very rapidly, and the technology to do that in an electric fashion simply doesn't exist.

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23 hours ago, MrWookie2U said:

non modded KSP uses parts that have IRL counterparts so I’m trying to make an electric rocket for possibly irl use.

I know you said "no mods" but lots of mods have IRL counterparts too, and tend to be quite well balanced. Some mod makers do college-level homework or higher, to make sure that their things are as accurate as possible. They are usually limited to things that were and have been and would be obsolete today or in a few years, but some focus on things that are well documented in concept and could have been or could happen.

Your goal is technically unachievable in pure stock so in comes everyone suggesting that you use liquid or solid rockets to get your electric craft into space as usual.

18 hours ago, MrWookie2U said:

Wandering why they made “green” or electric engines impossible?

These things were not possible or not popular in the time that KSP sets itself in (roughly 1940 to 1960). Clean energy and capable electric engines are only now beginning to become practical and it will be decades before any (for planes or rockets) get to have actual working prototypes. They are still mostly far off in the sci-fi world.

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8 minutes ago, JadeOfMaar said:

the time that KSP sets itself in (roughly 1940 to 1960)

I would say KSP represents 1960s-21st century tech as well, as we have analogues in stock parts for vehicles such as the Space Shuttle, SLS, and Ariane 5/6. But yes, early career does seem to emulate the late 1950s/early 1960s.

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1 hour ago, Streetwind said:

@MrWookie2U If you're fine with having a traditional launcher to place the thing into orbit, ion drive spacecraft are not that hard; the only part that requires real design thought is the power delivery. It basically goes like this:

  • Build the science probe you want to use: probe core, antenna, instruments, batteries. It should be in the 0.625m form factor. Larger ion probes are perfectly possible, but let's keep it simple for now. Make sure you have control authority (the OKTO-2 for example doesn't have reaction wheels).
  • Attach a single inline xenon tank and a single 'Dawn' ion engine. Check the dV reading in vacuum. If it's way more than you'll ever need, axe the inline tank and use two radial xenon tanks instead. But keep a healthy amount of excess dV, because you still have to:
  • Add power production. One Dawn engine consumes roughly 8.75 Ec/s. You have two options for the general power architecture, and each of them has three possible variants in terms of part choices.
  • Option 1: full power delivery. Use this if you're not sure how long your burns are going to be, or if you simply don't want to be limited by your power production. As such, you need to provide a solution that produces the required 8.75 Ec/s at all times, even when the engine is off. That means it's potentially going to be pretty large and heavy, and sitting unused most of the time. But it's worry-free.
  • Option 2: buffer with recharge. In this scenario you would provide only a part of the required 8.75 Ec/s in power production, and additional battery buffer to get you through your burns. Because batteries effectively weigh less than power production equipment, this makes the spacecraft lighter, which increases your TWR and your dV, and makes the required launcher smaller. And since the power production equipment is going to do work even when the engine is off, to refill the batteries, you're getting more value out of your investment. However, this places a hard limit on how long you can run your engine at full power. If you produce 4 Ec/s and have 1000 Ec energy storage, then the engine (plus probe core) will be able to run for 200 seconds. Any burn longer than that will require you to throttle down to less than half thrust - and the ion engine already has anemic thrust to begin with.

 

The third option are solar panels. They seemingly have all the upsides: small when folded up, attachable anywhere, mass efficient, good power delivery. Ideal in every way. However, if you're in the shadow of a planet, they're going to be useless. And the way orbital mechanics works, you'll always be in Kerbin's shadow for the majority of a burn that's going to the outer planets (Duna, Dres, Jool, Eeloo). Which means an ion engine spacecraft without sufficient battery buffer is going to struggle to even get on its way. And then there's that thing called the 'inverse square law'. The intensity of sunlight is inversely proportional to the square of the distance from the Sun. So as you're moving away from the Sun, going to the outer planets, your solar panels are going to get weaker and weaker. At Duna, you might still be getting roughly 40%-45% of their rated power; at Jool, you'll barely be getting 4%. Trying to power the hungry electric engine with that is going to be a real challenge. 

  • RTGs are always going to be using the buffer-and-recharge strategy. Fuel cells are almost always going to end up doing full power delivery. Solar can go either way, depending on the use case.
  • If you're going to Duna, solar is still fine. You can go for full power delivery at Kerbin and bring some extra batteries so you can run buffer-and-recharge at Duna, or deliberately bring twice as much solar power so that you'll still be at full power at Duna. It'll carry a mass penalty, but it's not that bad. Most of the time you're still going to need plenty of batteries anyway, though, because your transfer burn is on Kerbin's night 

Got it. Spam batteries and add like 10 solar panels. XD

 

Also, forget about the “green” thing. I don’t want that to haunt my posts for the next forever (it’s too late isn’t it)

 

im just gonna go to sandbox. Science mode is pointless when you think about it. Why limit yourself unless you have to. 
 

thanks for the help and ideas. 

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1 hour ago, MrWookie2U said:

Got it. Spam batteries and add like 10 solar panels. XD

Kind of:

331CFD4955F9F0B4C9FAA5217870144A6DAE3C4BE0C3AA506CEF128F05E85DC38C32528FF6D1541D

1 hour ago, JadeOfMaar said:

I personally dislike career mode.

Dont You like grindy exploatearism comrade?! You have to do a career to pay taxes and as obidient citizen fund space projects!

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Or get infinite cash in sandbox. Like what government really has (tax $) 

 

did you know that a government space program’s (like “nasa”) funds are 97% tax dollars. If it’s company ran programs, then yes contracts. 
 

you need to decide if your going the government route or the civilian company route. 
 

or you can do the gov funded scientist route (science mode)

 

if I’m not 100% right about this stuff, please note I do minimum research in anything NON video game related 

 

Anyway, I’m gonna go government route(sandbox) for now. I need to re learn how to make a rocket NOT blow up 

 

if Xbox 1 has recording features I might make a YT series (pls note I have never done YT before, so If it even gets out, it might be a long time, we’ll see) 

 

if you guys have any idea how many batteries I spam on my rockets, you would know I normally need to fast forward for 10 minutes to refuel in orbit of kerban (not counting time in shadow) in order to recharge only 1/2 of it. And that’s with over 20 solar panels. 
I should be good for a year with one charge. 
 

the only problem is steering. Can’t control it sometimes. And the steering assistant gives me trouble as well (although it might be cuz I don’t know how to use it :-\ oh well)

 

pls post more ideas?

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3 hours ago, MrWookie2U said:

Or get infinite cash in sandbox. Like what government really has (tax $) 

It do not exchange for infinite dV. Have You ever live in country where goverment is printing money with this idea? I did - 1 changed to 1000000 in purchase power until in few years.

11 minutes ago, Spricigo said:

Want to. That is all the reason someone needs to take an option over another.

Because there are places with lot of sunpower and there are some dark "corners" far from the Sun.

There are light probes and heavy crew mission (because of weight of snacks).

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