Ion and Electric Engines... What Use Are They?

[QuantumX]

OK, i have tried to experiment with the Ion engine and the RLA Electric Engine Mod, and to me they seem useless?

I have tried outfitting a Kethane probe with these engines and thought i could use them efficiently to change orbits to do a full planet scans, but they just don't seem to have the power to do anything...

Am i doing some thing wrong?

[Hunter12396]

long range journeys like sending a kethane probe to different planets but they have to burn for an hour to an hour and a half to get there never mind the capture burn

[annallia]

They aren't useless, just not quite useful. That said if you don't mind the long burns I find they work well for changing the orbits of small satellites, but that is about it.

[SyberSmoke]

The Ion Engine does not work like a rocket, they have a very very high fuel efficiency but have a very low thrust. The point of them is for probes that you do not want to spend a lot of mass on to get to some place.

The problem is this is an engine that would be BEST with a defined path and just left alone, and I mean with out a player sitting there drooling as it goes. This way the drone can do all its burns and so on and the player can do something less mind numbing like build and launch that spanky new rocket...or blow up that spanky new rocket.

[Anton P. Nym]

For one thing, if I've done it right, ions let me make a Moho orbiter probe that, including boosters and gantry towers, weighs 10 tonnes...

-- Steve

[Lazro]

You need to have patience. Watch a video or read a book or something while it's burning, set up a timer to tell you when it's done.

[Liudeius]

Since ions are only good for probes, you might as well use a nuclear engine to go to your location, and deploy the probe with a tenth the burn time.

After the probe has been deployed, if you ever intend to adjust its orbit, ion engines are useful since they last for a long time without refueling.

However, unless you are specifically trying to do something crazy (flying a single stage space plane from Kerbin to Eve), you should never use ion engines for interplanetary travel (or even to get to moons). Hours of your time is worth far more than putting a tiny satellite in orbit with fictional efficiency.

[Anton P. Nym]

Hours of your time is worth far more than putting a tiny satellite in orbit with fictional efficiency.

Physics warp is my friend. Also, I tend to do housework while the system handles my ion burns; they consume very little of my time... and thanks to having an 8-core* system while KSP only runs on 1 core at a time, it doesn't even take up much of my computer's time either. (Which I value much more cheaply than my own, to boot.)

I admit that in the sandbox mode we have now there's little direct in-game incentive to use ion engines... but as I have noted many times before here, they will certainly come into their own in career mode when parts inventories and budgets matter a lot more.

-- Steve

* well 8-core virtually; Intel's hyperthreading on the i7 makes Windows see my 4 physical cores as 8 separate cores. Works out fine by me...

[ZenithRising]

However, unless you are specifically trying to do something crazy (flying a single stage space plane from Kerbin to Eve), you should never use ion engines for interplanetary travel (or even to get to moons). Hours of your time is worth far more than putting a tiny satellite in orbit with fictional efficiency.

Hee.

I've used ion drives in the final stages of very low mass probes (less than a ton). One flew by two Joolian moons and settled into a nice tight 300km Joolian orbit using only its ion drive (and some aerobraking). Granted, some of the burns were over an hour long (I did house work and set a timer), but the delta-v of an ion drive can't be beat if you're willing to wait for it.

That said, I've since gotten better at both flying and rocket design, and haven't used up the fuel on my pre-ion nuclear stage since.

[Dortmunder]

I generally just have them on satellites as an "incase I need to make adjustments" plan, after I've ditched the main engines to get there.

[Cannibal]

If you have a wide maneuver window and patience they can be extremely useful, even with heavier loads.

I have a resource carrier probe I send ahead to planets and moons that carries liquid fuel, rcs, power and nuclear engines for the return journey of a manned pod later. It has ion thrusters that I used last night for a 7 hour capture burn at Eeloo. I literally left it running overnight, but that was several hundred m/s of delta V in only a few tons of mass (xenon + engine + power).

Power is a big problem out by Eeloo though as most of it has to come from RTGs.

[Spyritdragon]

I use ion engines for orbital adjustment of science probes. I attach an ion engine to my probes to preform orbital adjustments, just in case. They're so compact its fun to have them on there, rather than an orbiting probe that has no way whatsoever to move itself. And the extreme compactness of most of my probes that are fitted with ion engines provides that they actually have a noticeable acceleration when using the ion engines. My standard 'Bobalite'-class science probe is really just a octo core, the science instruments, two antennae and a sattelite dish, an SAS module, some batteries and two 1x6 panels. Adding a xenon container and an ion engine to that just gives me the good feeling of having mobility, more than anything. Good for precise orbit adjustments :-).

[QuantumX]

Thanks for all the answers Gentlemen...

[Skorpychan]

I've currently got a design that drops a set of tiny ion probes in a system from my standard interplanetary transfer stage. That enables me to do all sorts of interesting stuff while relying on having backups and not having to fly another mission out for one little accident.

For example, close inspection of atmpshere-less bodies. Or inspection of a body's atmosphere; I intentionally had one plow into Eve to see what would happen. Provided useful data for my kerbed mission, before it exploded.

There's a surprising amount of thrust in them if you're stingy with the construction. Enough solar panels to power the things, an RTG for backup, and some batteries for nighttime burns, and you're good. They eat a hell of a lot of power, but use very little xenon.

[NeoMorph]

Like others have said, LONG journeys and for satellites that need adjustments like for the comms sats that need to stay in geostationary. They are always moving out of position in my setup.

It's a shame you cannot program in a set of commands and then switch to other ships to do more interesting stuff.

[ZenithRising]

I've currently got a design that drops a set of tiny ion probes in a system from my standard interplanetary transfer stage. That enables me to do all sorts of interesting stuff while relying on having backups and not having to fly another mission out for one little accident.

For example, close inspection of atmpshere-less bodies. Or inspection of a body's atmosphere; I intentionally had one plow into Eve to see what would happen. Provided useful data for my kerbed mission, before it exploded.

I love this idea.

I've been playing a lot with mini probes myself lately, as they are easy as heck to put pretty much anywhere I want. This is my current design I'm quite enamored with:

The whole thing, including the engine, 1000+ Xenon, and 18.00/s worth of solar panels still only weighs 0.8 tons. That solar panel array at the top generates as much power as one of the big ones at half the mass, and as an added bonus, works at close to peak capacity (80-90%) no matter what way the ship is facing. It generates enough power to get (almost) full thrust out of the ion drive as far out as Jool. However, if the probe is seeing diminishing returns from the panels, they can be jettisoned along with the larger xenon tank to bring the mass down to 0.5 tons.

[Liudeius]

Physics warp is my friend. Also, I tend to do housework while the system handles my ion burns; they consume very little of my time...

You can physics warp, and ignore an hour long burn without mods? I can see a capture burn working, but if you're already in orbit, wouldn't you change trajectory too quickly to entirely ignore it?

Perhaps once career comes out ion's will be better, but for now I'll stick to nuclear transit stages because cost doesn't matter.

I can't believe they will leave ion's as they are for career though. I expect either a slight increase in power to put their burn times nearer to nuclear for small probes, or a way to set them to burn automatically. KSP may be a sort of simulator, but I doubt it is Squad's intention to simulate space travel as accurately as spending hours doing nothing/ignoring the game.

[harharluke]

Ignoring all previous posts and probable answers because I'm far too lazy to read them all, I just tell MechJeb to do a burn then go off and do something else while it burns for however long it takes and MechJeb is accurate to 0.1m/s with maneuver nodes so I don't have to worry about burning to much

[Anton P. Nym]

You can physics warp, and ignore an hour long burn without mods? I can see a capture burn working, but if you're already in orbit, wouldn't you change trajectory too quickly to entirely ignore it?

I don't use ions for major orbit changes that way... if it takes an hour to do an inclination burn, I've set things up poorly. So far I've mainly used them for capture burns and minor orbit changes. When I execute on Project MINIMOHO, I plan on doing my injection burn by setting-and-forgetting though I tried to set its initial orbit up to help make the burn as straightforwad as "aim at the Sun and burn hard for X hr Y min". It'll be interesting to see if that works.

-- Steve

[Tank Buddy]

Because of realism, they practically are useless. Unless you have hours of free time, don't use them.

[Niccolo]

I love ion engines! Not sure why... I mean, they have all the thrust capability of a hard sneeze. But they look pretty cool, in a serene, spacey sort of way. (I also think that they look like the in-car cigarette lighters...)

I mostly stick them on any satellite I fling up. Nice and light and very easy to make precise orbital adjustments with. But I haven't really experimented too much with the game (My hours have only recently hit double digits, unlike those who've clocked several hundred) so I don't really know what I'm doing just yet.

[Starwaster]

I use them all the time. They're great for satellite orbital changes and I once sent a probe out around the sun

[JiWint]

Good for moving satellites