Ion supliment engines on manned craft

[Dun Kirk]

Apart from probes are Ion engines worth attaching to standard space craft? Ie having 2x nukes and 2x Ion.

Thanks

[Octavianus]

In my opinion: no. Ion engines provide Delta V VERY slowly, so unless you plan to use a ton of them, I'd suggest going for nuclear engines only.If you really want to use Ion engines you'll have to strap on your spacecraft much more than 2 of them

[Wallace]

if you have 2 nuclear engines and enough fuel to make them worthwhile then that craft would be way too heavy to make ion engines effective.

If the ship was just a mk1 pod ion engines then maybe.

[QuantumManiac]

I haven't really tested the ion engines but where are you going to use it? if it's in orbit of a planet it won't do much unless you have ten or so ions strapped to it. I would say you should have 4 ions for travelling between planets and the nuke engines for in orbit.

[Darkeldar]

I just explored Duna and Ike with a probe powered by a single ion engine, and boy those hours long burns without the ability to warp really tries your patience. I got both high above and near series of experimentation done to gain around 2k-3k science. On Ike approach, though I used my RCS as I got impatient, and understood that with about 500 units of xenon (out of 3700, at launch), the probe wasn't going to be able to go any further to get new data. I was using eight 1x6 solar panels the power the probe, and at times had to throttle the engines back as to balance electric power in vs. power being used. I'd post a screenshot, but this isn't working for me currently. Used the last of the xenon to escape Duna and ended up with a elliptical kerbol orbit.

I wouldn't recommend ion drives unless you want to babysit KSP as it resolves your maneuvers.

[Col_Jessep]

I can think of exactly one use for ion engines on a normal ship: fine adjustments to orbits like orbital period for geostationary orbits. Due to the very miniscule power of the ion engine you can use them for very precise adjustments. One ion engine has half the power of a single RCS thruster and if you run them on minimal power they should be 20 times as precise as RCS.

[Nobody]

As the others have said Ion engines don't have the thrust to be efficient as propulsion of manned craft. In real life they are used on deep space probes due to their low weight and fuel efficiency.

There are creative uses for this game's unrealisticly powerful Ion engines. Some examples are precision maneuvering, applying down force to rovers on low gravity worlds, and if you feel really crazy hover craft on low gravity worlds.

[SgìobairOg]

For the Ion engines to really be useful we'd need to be able to leave a ship throttled up while we go do other things.

[Traches]

I just explored Duna and Ike with a probe powered by a single ion engine, and boy those hours long burns without the ability to warp really tries your patience.

You can use physics time warp (alt+.)-- 4x is better than 1x. Still takes forever though.

[jordanjay29]

For the Ion engines to really be useful we'd need to be able to leave a ship throttled up while we go do other things.

Respect to those who play without it, but this is one time when I really make use of MechJeb. Set the maneuver node, set MechJeb to execute it, and go to class/sleep/work/etc. Come back and my probe has powered through and is on a course for my destination.

[700NitroXpress]

They can be useful on really light weight craft, otherwise you need a lot of them like this,

This is my Armadillo APC. The Ion engines on the back can get it up to a good land speed on Mun, but you also have to add a lot of solar arrays and generators to power this many.

[Darkeldar]

I was sandboxing with another ion drive probe and using MechJeb. Really wish MJ had an option to set throttle when auto-piloting, as at full burn the drive uses up energy faster than the panels can recover it. This causes the drive to stutter, as the battery power is used up, as it gets just the charge for a burst. I don't know if the effect ends up being the same i.e., stuttering at full throttle or constant at a lower throttle setting? But with ion drives, the burn estimate is really just a estimate.

Oh and I did just get the reactor this weekend in the career mode, so don't bring that up as an option...I'll get there.

Edited November 4, 2013 by Darkeldar

[Mmmmyum]

I was sandboxing with another ion drive probe and using MechJeb. Really wish MJ had an option to set throttle when auto-piloting, as at full burn the drive uses up energy faster than the panels can recover it. This causes the drive to stutter, as the battery power is used up, as it gets just the charge for a burst. I don't know if the effect ends up being the same i.e., stuttering at full throttle or constant at a lower throttle setting? But with ion drives, the burn estimate is really just a estimate.

Oh and I did just get the reactor this weekend in the career mode, so don't bring that up as an option...I'll get there.

It does have a throttle limiter, it's in utilities I think... And I find that the weight of all those RTGs tends to make that ion engine work even harder, as you need so many of them

[toomuchbrew]

I think having to bring two types of fuel and extra power to run the.ions defeats the purpose. At least rcs is versatile.

[Skorpychan]

Short answer: No.

Long answer: Ion engines have such wimpy thrust that you'd gain nothing from it.

[numerobis]

It does have a throttle limiter, it's in utilities I think... And I find that the weight of all those RTGs tends to make that ion engine work even harder, as you need so many of them

I was going to write this "next" when I wrote the jet flameout code (because it is pretty similar in concept), but never got around to it. Certainly would be useful, if anyone is looking for a project.

[Darkeldar]

It does have a throttle limiter, it's in utilities I think... And I find that the weight of all those RTGs tends to make that ion engine work even harder, as you need so many of them

Thanks, I gave it a try at lunch and was able to adjust to use 43% throttle, without pulling power from the batteries.

[Skorpychan]

Nuclear engines are four tons apiece. Plus fuel, struts, and the rest of the craft. The benefit you'd get would be cancelled out by the solar panels needed to run the ions, as well. It is not worth sticking ion engines on a nuclear craft, except as an emergency thruster to get you home. And even then, the acceleration would be so tiny on a heavy craft that you'd be waiting for hours real-time to do anything, even at 4x physics warp.

My ion probes take annoyingly long times to get anywhere, even when they're under two tons.

Edited November 5, 2013 by Vanamonde
Quotes deleted comment.

[numerobis]

LV-N is 2.25t

I've used ions to get a kerbal can to the Mun. I've also used ions to do small adjustments on a 30t spacecraft going to Laythe from Kerbin.

[Traches]

Ions pointing up work decently as downforce to keep your low-grav rovers under control. Kinda.

[bludy]

i used them on a one manned jet pack for mun explorations and on land probes..working on a solar powered aircraft..big structures precision adjustments seems a serious thing :-)

[UberFuber]

As the others have said Ion engines don't have the thrust to be efficient as propulsion of manned craft. In real life they are used on deep space probes due to their low weight and fuel efficiency.

There are creative uses for this game's unrealisticly powerful Ion engines. Some examples are precision maneuvering, applying down force to rovers on low gravity worlds, and if you feel really crazy hover craft on low gravity worlds.

Kerbal Ion Engine - 500 Newton of thrust

Compared to real-life:

http://en.wikipedia.org/wiki/Ion_thruster

Maximum thrust? 5 Newton

Real-life ion-engine user do have the advantage that we can just set them on auto-pilot (tell probe to keep itself aligned and turn on ion engine for 1000 hours, go back to do other space stuffs). It would be nice if the game could let us set a burn-schedule for engine and then go launch another space-craft, even if it means no more than 4x physics warp, it would mean that I can do other stuffs like refueling my space station or construct a giant, Jool bound manned spaceship in orbit.