Ion engines

[darkmuminek]

I've been looking for some moar scienceâ„¢ and ways to mess around in KSP so I thought: Why not <strike>Zoidberg</strike> ion engines. The idea was to build some small probes, send them everywhere, collect science and maybe return to Kerbin.

I built the probes, launched them into space, decoupled those awful, fuel consuming, fire blazing, exploding rocket engines, started my ion engines and, with a smile as wide as Jebediah's, throttled up just to... get disappointed.

I know ion engines aren't powerful but achieving the speed to get to Mun from high Kerbin orbit would take over 30 min. burn which is extremely boring considering you can't switch vessels when they're throttled up. And this is just going to Mun, I hadn't the courage to check how long would it take to reach Duna.

So instead of asking for help with stock ion engines I want to ask you: what are you using them for? I can think of two things:

1. Fine tuning your orbital period to achieve stationary orbit.

2. For any other maneuvers with small and light craft requiring precision and small changes in velocity.

However, you can do exactly the same with RCS, which gives you more control and doesn't need large amounts of electricity to function.

[Felsmak]

I use them to go to Moho.

[TimePeriod]

I believe the stock version of the ion engines takes one XL solar panel, simply add more.

[darkmuminek]

Felsmak: I believe you can get anywhere with these engines as they are highly efficient. However it takes ages

TimePeriod: Providing electricity isn't a problem. Actually there's no problem at all. I just wanted to know what are you guys using the engines for.

[Superfluous J]

I don't use them. However, note you can physics warp, probably up to the maximum 4x by holding alt and hitting '>'. This will bring that 30 minute burn down to a slightly more palatable 8 minutes.

And Duna should take not much longer, though have fun slowing down once you get there.

[MockKnizzle]

This shouldn't be a surprise if you are aware of what real-life ion propulsion is like.

[darkmuminek]

I'm not aware and frankly don't give a damn Just wanted to know what can you do with them that doesn't include long lasting burns.

[Tw1]

I travelled from Eve to Gilly.

Ion engines are very convenient when you need tones of delta V for something smallish- This probe didn't really take have most efficient trip to Eve.

Ion engine flights are something to do when you've go lots of spare time, or mechjeb's burn automator, and other things to while you wait.

Edited January 30, 2014 by Tw1

[FuzzyLlama]

Yeah, pretty much the only thing I can think about is really really long, fuelless voodoo rotation and translation of your intergalactic boring-boat.

Just bring the extra hydrazine.

[Spyritdragon]

I'm not aware and frankly don't give a damn Just wanted to know what can you do with them that doesn't include long lasting burns.

I use them for my one-tonne Remote-Jebby sattelite. They're designed specifically to be movable by these ion engines, and even then i usually have them placed in their respective orbits with a more powerful engine - the ion engine is used to preform orbital transfers - i can hop them between 10 km and million-kilometre orbits as many times as i want. The probes themselves dont have much functionality though - usually just gravity readings and stuff. Sometimes i might add a goo container or a materials bay, but this increases probe mass again.

I also have a larger variant which sports three ion engines, and can preform all space-bound science operations.

[darkmuminek]

OK, I'll probably just stick to standard rocket engines. I remember there was a mod with more powerful ion engines... Ion Engine Propultion Pack I think. Anyone knows if it's still supported? I didn't see it anywhere on the forums.

[zxczxczbfg]

It is possible to make very tiny planes powered by nothing but ion engines and solar panels. As expected, they're quite efficient, but they have little thrust.

[Wooks]

In ye olde times you could power super fast rovers in low gravity planets / moons with a single ion engine, haven´t tried that one in the newest version.

Mad Scientist advice: Strap 20 ion engines to a single ship, make sure all of them have proper access to fuel and electricity. Come back and share your experience with us... if you survive muahahahHAHAHAHAHAHAHAHA... ha!

[Scotius]

http://forum.kerbalspaceprogram.com/threads/31286-0-22-Ion-Hybrid-Electric-Pack-30-08-13-NEW-RELEASE-v2-2-IP-15-Radial-Fix

http://forum.kerbalspaceprogram.com/threads/52042-0-23-Near-Future-Propulsion-Pack-0-33-1-%28updated-24-01-14-balance-changes%29

Take a look at engines from these two mods. Near Future is better IMO (and maintained ).

[Tank Buddy]

I have a whole base on Gilly entirely based with ion engines Of course, I had to use chemical (or rather, nuclear) rockets to get there. Gilly's gravity, .049 m/s^2, means the ion engine has a TWR of 40.8. It works great, and there is no way I will ever have the will to use up all of the Xenon. Also, it is closer to the sun, so I never run out of charge. The only thing is orbital velocity is ~15 m/s, so it takes time to get to the surface. Especially since you can't time warp fast enough near the surface, but you definitely have enough acceleration.

I did send 2 separate missions to Pol with ion probes, but to no avail. It might work if I had more solar panels (running out of charge), but the TWR still isn't that good. Your best bet for everything other than Gilly are chemical rockets.

I wish Ion engines could be more practical, but in order to maintain realism, they could never be so.

Your last point is true.

[Captain Sierra]

1) NFP is amazing, nuff said

2) It sounds like you are trying to push too heavy a craft with them. If you are using a manned craft with stock ions, you're doing something wrong. If it's over 2 tons and you're using ions, you're doing something wrong.

To get the most out of your ions, either get more powerful ones (KSPX, but these require stupid ammounts of power), or go smaller. Also, ions are terrible for escaping kerbin. They are super efficient so the advantage is not taking as much fuel with them. While in LKO, you have the advantage of refueling, so I advise using a chemical (or optionally nuclear) transfer stage for the ejection burn.

[Ravenchant]

Ion-ing is useful for small probes, but you have to be patient. I once did an insertion from Kerbin to Duna that took almost 50 minutes. Ended up setting a phone alarm, else I would have forgoten to finish the burn

[Guest]

I use them for small probes. Really small. For things that take longer than 10-15 minutes I use kerbal alarm clock and go make lunch or something.

[darkmuminek]

Yeah, I figured I could go for a smoke or play with my guinea pigs while the engine pushes the craft

The probe I tested it with wasn't that heavy, I think. It had a probe core, two XL Solar Panels, two small deployable radiators from KSP Interstellar and some batteries + light science equipment (no goo containers or science jrs) and of course one xenon container and the ion engine. Can't remember how much did it weight.

The Near Future Propulsion Pack is a no go. I've got too many mods installed already and the game crashes when I install any other part packs. However I have Interstellar and it has plasma thrusters IIRC. Anyone tried them? How do they compare to stock ion engines?

Wooks, I definately must try these ion powered rovers

Also, ions are terrible for escaping kerbin.

So if I use any other type of engine to escape Kerbin, ditch it and switch to ion it will be better? I mean, will they perform better when braking to establish an orbit around, say, Duna or Eve then when trying to escape Kerbin SOI?

Edited January 30, 2014 by darkmuminek

[Streetwind]

When it got time to put kethane scanning probes into orbit, I experimented with ion thrusters... but in the end, I went with conventional engines again.

My ion probe weighed 0.6 tons, with 0.5 kN thrust. My conventional probe weighed 0.8 tons, with 1.5 kN thrust. That's almost three times the thrust/weight ratio even when fully fueled, and increasingly more as it expended fuel. The conventional probe could do everything the ion probe could do as well - travel all the way to Mun and Minmus, place itself into a polar orbit, circularize at the desired height and so on. And it did so in a much, much more convenient and comfortable way.

Admittedly, the ion driven probe had more than 90% fuel left after completing its maneuver, while the convenional probes had barely enough left to maybe deorbit themselves at the end of their useful lifetime. But well, what am I going to do with all that leftover fuel? The probe is not going anywhere else anymore. You really need to fly very long distances if you want to make ion engines worthwhile, and those really long distances are going to take a really long time. There's not really much of a way around it.

Edited January 30, 2014 by Streetwind

[Bekiekutmoar]

My soon to start manned (4 Kerbals) mission to Moho will rely partially on Ion Engines. The journey to Moho will be done with a nuclear engine. The journey back to Kerbin will be performed with 2 Ion Engines, the ship will then be essentially a Hitchhiker Container with some other stuff (total mass below 3 tons).

[Wooks]

Wooks, I definately must try these ion powered rovers

As I told you it was ye olde times, when proper rover wheels with autonomous electric propulsion where not present in the game, and it was an impromptu solution to create something that didn´t actually existed on the game. Now you have an array of wheels to create rovers to your hearts contempt only using an electric source to power the wheel.

If you really want to recreate an old version for testing be advised that using ion engines on a rover only would work properly if you use the Small Gear Bay

Edited January 30, 2014 by Wooks

[darkmuminek]

I know that now we have electric propelled wheels, however it doesn't stop people from straping boosters to their rovers I'll just try that for science. Yes, science and absolutely nothing else...

[Aragosnat]

Also Ion Drives can be used to press rovers to the ground on low Gravity moons like Minmus and Gilly. Where it is very easy to catch air and lose traction. When and if they will ever add other stars to the game. I would be using Ion Drives to send probes out to them.

[Soda Popinski]

I've been using ion engine driven probes on my Jool mission, sending them out from my base orbit around Vall. Yes it takes forever. I use RemoteTech2, and set the flight computer for prograde, and set up burns for however many m/s delta-V is needed. Just did a 30 minute burn while I ate dinner.

To see some really interesting things done with them, check out Macey Dean's ion drive powered fighters. I suspect most of the delta-V is from RCS, with the ion engines just to look cool.