the ion engine is way too OP

[Oksbad]

A possible solution to the long burn times of ion drives would be to enable some form of time warp when using low thrust methods such as ion drives. Effectively giving them the same thrust as small chemical rockets completely kills the point of an ion drive. They're supposed to have very low thrust.

[Levelord]

I don't understand how people say Ion engines are overpowered.

1) The Delta V for the old and new versions are EXACTLY the same. It doesn't make you travel further than it already does. You take a 1 hour burn to get to Jool for the old one, and you take a 15 minute burn in the new one. In the end of that burn both will still have the same amount of Xenon fuel left in their tanks when they both reach Jool (because the newer version has a higher fuel consumption rate). Having a higher thrust doesn't make you travel further than you already could in the previous versions.

2) You can put the ion engines into gliders, BUT:

A: Ion powered gliders take forever to get anywhere in atmosphere (which means you are essentially playing the same boring routine of long ass burns).

B: It's still better off using jet engines or rockets to get to your destination in atmospheric gliders.

C: There aren't that many places to visit on a glider, and the places that you do want to visit, can be landed directly on from orbit anyway.

3) The only difference in the ion engines are on burn times. Since the dV is the same, and you don't travel further than where you can already go in previous versions, the only 'overpowered' aspect is the wait time. If these people think waiting times are a form of challenge, they need a swift knock to the head.

Kerbin is scaled down to a tenth of the Earth's size to cut down on the time it takes to get to orbit. The Kerbol system is scaled down to facilitate interplanetary travel. Time warp is implemented to cut down on time to travel to the Mun or interplanetary travel. The whole game is designed to shave off those useless time spent staring at the screen doing nothing.

If you can build it and if it has the dV, the game will let you go there. KSP is only concerned about seeing you get to your destination to explore, it is not a game about waiting around twiddling your fingers during a 2 hour burn.

Edited April 7, 2014 by Levelord

[SSSPutnik]

The increased thrust means you can now use them to land on more bodies than you could before...

[Levelord]

The increased thrust means you can now use them to land on more bodies than you could before...

On what bodies? Gilly? Minmus?

All the super low gravity bodies that you can already land on (and take off) using the ant engine (or even RCS) which is faster responding than the ion engine and uses less power and weighs less?

[Tangle]

If the Ion engine was exactly as it is IRL... well, let me just say good luck on that seventeen-day burn.

[3_bit]

While it does reduce realism... KSP was never meant to be a perfect reality, unless Squad's target platform was university Supercomputers.

One Jool-bound ion craft I made while back had a burn time of over 3 days. It did, also, have only 3 ion engines and a dV of over 8,000 m/s.

The increase in thrust would make me much more comfortable doing a legitimate mission and not just going straight to the fast and easy Mainsail Interplanetary Stage.

[zarakon]

Has anyone managed to reach Kerbin orbit on Ion power alone?

[cantab]

The increased thrust does result in more "effective" delta-V. Firstly because if you have the same number of ion engines your burn will be shorter, and the shorter the burn is the more efficient it is. Secondly, if we assume you have a maximum burn length tolerance, you can now meet that with fewer ion engines and thus less dry mass; the reduced electricity requirement lowers the needed dry mass even further.

That said, the effects are likely to be minor.

EDIT: @zarakon: Not that I know of. Even after the buff you still can't do it by a vertical launch, you'd have to use an aircraft. But I don't know if you could get enough speed up to reach orbit, given you've so little force to overcome drag with.

[Levelord]

You can have the same amount of dV by doing several orbits and doing short burns at the periapsis by taking advantage of the Oberth effect for the old engines.

Even so... The new ion engines are not buffed to the point where you can do a single interplanetary burn, so you are still going to have to do Hohmann burns several orbits anyway, just less orbits this time. So the technique is still preserved, but the time wasted doing it repeatedly is reduced. I burn for Jool after 7-8 Hohmann burns, you do it in only 4-5, and we still end up with the same fuel and dV when we break Kerbin SOI.

Your second point applies to any craft that is designed to be smaller with a lighter engine, like the ant or 48-7S engines. It's not a unique feature of the ion engine.

Edited April 7, 2014 by Levelord

[KerikBalm]

The point is that you shouldn't be doing hohman burns at all with ion engines.

What we need is an engine that works during time warp/affects "on rails" calculations.

As it is now, the ion engine acts like a perfectly efficient ion thruster in the 40 MEGAwatt power range, (or more realistically, an ion thruster at 50% efficiency, with a power consumption of 80 megawatts).

Good luck getting 10's of megawatts of power output from solar alone...

[Levelord]

The point is that you shouldn't be doing hohman burns at all with ion engines.

You are supposed to be doing Hohmann burns with any engine/craft if you want maximum dV and efficiency, and it becomes more important the slower the engine is (eg. Nuclear and ion engines).

If you don't do a Hohmann burn, you're wasting dV even on the buffed ion engines and would be lucky enough to even break Kerbin SOI.

[KerikBalm]

Nope.... hohmann burns aren't possible with real ion engines at the given power levels*, so instead they do brachistochrone trajectories.

You shouldn't be trying to do something that isn't possible.

Because of the way ion engines work in KSP, we're always doing hohmanns, and never doing brachistichrones... its a shame.

*sure, in theory you could perapsiss kick for your outbound, but that would take far too long, and you wouldn't be able to do a burn for capture at the destination... you'd go whizzing by, and fail your hohman transfer.

With the OP'd "ion" engines in KSP, yea, you should do Hohmann's to maximize efficiency.

But the point is that a real simulation of flight with an ion engine would have you doing a brachistichrone trajectory, not a hohmann transfer.

[The Error]

I'm sorry, but-

You shouldn't be trying to do something that isn't possible

- why shouldn't I? This is K.S.P., not Orbiter. If I want to try and break physics, I will.

This discussion seems to be degrading into "You're having fun/using ions the wrong way!", and frankly, that seems entirely pointless.

[Levelord]

Nope.... hohmann burns aren't possible with real ion engines at the given power levels*, so instead they do brachistochrone trajectories.

You shouldn't be trying to do something that isn't possible.

Because of the way ion engines work in KSP, we're always doing hohmanns, and never doing brachistichrones... its a shame.

*sure, in theory you could perapsiss kick for your outbound, but that would take far too long, and you wouldn't be able to do a burn for capture at the destination... you'd go whizzing by, and fail your hohman transfer.

With the OP'd "ion" engines in KSP, yea, you should do Hohmann's to maximize efficiency.

But the point is that a real simulation of flight with an ion engine would have you doing a brachistichrone trajectory, not a hohmann transfer.

Brachistichrone trajectories are done on real life ion engines to save time in real life, but doing repeated Hohmann burns is perfectly feasible, but takes repeated orbits and takes a longer time.

Doing brachistichrone trajectories in KSP ironically takes longer because you are limited to a 4x physical time warp while you manually control where the craft should be going (as opposed to 100x or 1000x on rails time warp to complete orbits for repeated short Hohmann burns). So the thrust was boosted to save time in KSP. If you feel you are talented enough to eyeball a brachistichrone trajectory, you are free to do so, but it's likely that it's better handled with an autopilot like MechJeb.

Either way, this has nothing to do with the changes to the ion engine's stat buff, because it doesn't change where you could and could not go from previous versions. The dV is still the same for both.

Your argument for realism would require you to sit in front of your PC watching your ion craft do a brachistichrone trajectory for 45 minutes to an hour, because you have to be constantly readjusting the heading of the circular arc and can't activate an on rails timewarp. The ion engine's updated thrust doesn't change anything except for a bit of time spent staring at your screen doing it. So you are absolutely free to spend your incredible amount of free time doing the maneuver for yourself for the sake of 'realism'. I just don't see how an ion engine buff stops you from doing it if you wanted to.

The final point is that a few orbits for Hohmann burns is not going to desync you from your destination and most of the time you are going to have to do interplanetary correction burns along the way anyway like any other conventional craft. I'd argue that brachistichrone trajectories are harder to do because KSP's maneuver nodes doesn't support it and setting up multiple burns is inaccurate; because of how the game gets less accurate predicting flight paths (conic patch) and the human error of trying to manually adjust the craft to face the changing maneuver nodes.

[Iron4venger]

I'm probably the guy with most experience in ions in the entire forums. I've created countless probes 100% ions, (even planes) and this is my list:

The increased x4 thrust is good. I'VE DONE a 24 hour long burn with ions in .22. And after that, I used Hyperedit to skip the burn and place the probe were I wanted it to be every single time. So if burns now takes minutes instead of days is a good thing. Sad to lose that long burns that makes nodes irrelevant because you gonna to burn during hours and hours well in advance and before the node point, but if nodes are irrelevant and theres simply no other way to navigate thru space, then, wtf ions man? GOOD

I find the electrical consumption a little bit too low, but I need to test more to be sure about this.

pd. My solar glider had 100m roof before, now it reachs 10km easy and I'm quite sure it's orbit capable.

Edited April 7, 2014 by Iron4venger

[DaveofDefeat]

Ion drive to powerful?

name = ModuleEngines

thrustVectorTransformName = thrustTransform

exhaustDamage = False

ignitionThreshold = 0.1

minThrust = 0

maxThrust = .01

heatProduction = 0

PROPELLANT

Done!

[Red Iron Crown]

Ion drive to powerful?

name = ModuleEngines

thrustVectorTransformName = thrustTransform

exhaustDamage = False

ignitionThreshold = 0.1

minThrust = 0

maxThrust = .01

heatProduction = 0

PROPELLANT

Done!

You're right, it serves no purpose to talk about game balance issues, or offer any feedback to Squad. Thanks for pointing that out.

[DaveofDefeat]

You're right, it serves no purpose to talk about game balance issues, or offer any feedback to Squad. Thanks for pointing that out.

Your welcome!

[Iron4venger]

In fact, and for reality reasons, exahustDamage should be True

[zarakon]

pd. My solar glider had 100m roof before, now it reachs 10km easy and I'm quite sure it's orbit capable.

I'd like to know if you really are able to get it to orbit

I think I've gotten mine to 20km and maybe 500 m/s

It takes a very long time to get there. DynamicWarp required! I always run into one of two problems though:

- Run out of xenon

- Run out of daylight

Loading up on more xenon makes the ascent take much longer, which means I run out of light sooner. I haven't tried using drop-tanks or flying west though.

(of course abusing infiniglide would make it possible, but I'm trying to avoid that)

[Jouni]

The ion engine is now a good choice for Mun landings, even with the relatively inefficient 2-kerbal lander can. I'm still not sure what to think of them, but at least the update changed the nature of the engine significantly.

[technicalfool]

Last time I tried to make an ion sun-diver, along the lines of the "This is KSP 3" sun-diver, the burn time was something like 18 and a half hours, and that's not including circularizing the orbit afterwards.

Life is too short. I never did get that sun diver down there. Maybe now, I might do.

[coolitic]

If you wanted to be realistic, then it would also use less power I believe.

[NERVAfan]

Last time I tried to make an ion sun-diver, along the lines of the "This is KSP 3" sun-diver, the burn time was something like 18 and a half hours, and that's not including circularizing the orbit afterwards.

Life is too short. I never did get that sun diver down there. Maybe now, I might do.

What was the mass of it, and what kind of orbit did it start from? I sun-dived a probe from a Kerbin type solar orbit in way less time than that... didn't keep track, but I don't think it was more than an hour (at x4), maybe more like 30 min?

[NERVAfan]

Brachistichrone trajectories are done on real life ion engines to save time in real life, but doing repeated Hohmann burns is perfectly feasible, but takes repeated orbits and takes a longer time.

Doing brachistichrone trajectories in KSP ironically takes longer because you are limited to a 4x physical time warp while you manually control where the craft should be going (as opposed to 100x or 1000x on rails time warp to complete orbits for repeated short Hohmann burns).

Yeah, the way it SHOULD work is allowing ion engines to work in on-rails time warp.

There's a mod for that (Orbit Manipulator Series), and I think KSP Interstellar has solar sails that work in on-rails time warp too.

Then drop the thrust to like .01, and then you can use it at 100x time warp and the burn takes 80% of the (real, player's) time it would with a 0.23.5 2kN max-4x-warp ion engine.

Either way, this has nothing to do with the changes to the ion engine's stat buff, because it doesn't change where you could and could not go from previous versions. The dV is still the same for both.

In terms of dV alone, no, but it DOES change where you can go in terms of being able to land with ions on more bodies.