ARM Parts Poll

[-Velocity-]

The new ion engine provides about 700 times more thrust than the most powerful ion engine ever created (2000 N in KSP vs. 3 N IRL)!!! Even though the older ion engines were still vastly overpowered, their balance was fine IF Squad had JUST provided a nuclear reactor part, and had they provided larger ion engines and larger, realistic-capacity xenon fuel tanks (a Jumbo 64 fuel tank, filled with liquid xenon instead of regular rocket fuel, would hold around 900,000 (ish) units of xenon fuel- 90 tons! Liquid xenon is around 3X heavier than rocket fuel).

[zarakon]

The new ion engine provides about 700 times more thrust than the most powerful ion engine ever created (2000 N in KSP vs. 3 N IRL)!!! Even though the older ion engines were still vastly overpowered, their balance was fine IF Squad had JUST provided a nuclear reactor part, and had they provided larger ion engines and larger, realistic-capacity xenon fuel tanks (a Jumbo 64 fuel tank, filled with liquid xenon instead of regular rocket fuel, would hold around 900,000 (ish) units of xenon fuel- 90 tons! Liquid xenon is around 3X heavier than rocket fuel).

Ion engines are another issue entirely. They may be overpowered compared to real life, but it's necessary since there's no way to automate a 2-month burn of a realistic one. They're still not overpowered within the context of the game because they're very specialized in what they do. There aren't any other parts that become useless in the shadow of the ion engine.

The new big engines are actually still underpowered compared to real engines. But again, that's a necessary difference because the whole Kerbal solar system is on a smaller scale. Within the context of the game though, they're overpowered. They seriously outclass the existing engines in multiple aspects with no significant drawbacks.

[Jouni]

Ion engines are another issue entirely. They may be overpowered compared to real life, but it's necessary since there's no way to automate a 2-month burn of a realistic one. They're still not overpowered within the context of the game because they're very specialized in what they do. There aren't any other parts that become useless in the shadow of the ion engine.

They are no longer that specialized. With the performance boost, the ion engines became a good choice for lander engines in many cases. You can land nontrivial payloads to Mun in a lander that's smaller and uses 10x less fuel than with the 48-7S engine. I don't think they are overpowered, but they certainly don't feel believable anymore.

[-Velocity-]

Ion engines are another issue entirely. They may be overpowered compared to real life, but it's necessary since there's no way to automate a 2-month burn of a realistic one. They're still not overpowered within the context of the game because they're very specialized in what they do. There aren't any other parts that become useless in the shadow of the ion engine.

The new big engines are actually still underpowered compared to real engines. But again, that's a necessary difference because the whole Kerbal solar system is on a smaller scale. Within the context of the game though, they're overpowered. They seriously outclass the existing engines in multiple aspects with no significant drawbacks.

They are no longer that specialized. With the performance boost, the ion engines became a good choice for lander engines in many cases. You can land nontrivial payloads to Mun in a lander that's smaller and uses 10x less fuel than with the 48-7S engine. I don't think they are overpowered, but they certainly don't feel believable anymore.

No, ion engines are now terribly overpowered.

IRL, ion engines (moreso related technologies like VASIMIR that the KSP ion engines actually more closely resemble) are only viable for a moderate or high acceleration propulsion plant of a large interplanetary spacecraft IF you pair them with nuclear reactors. Now, in KSP, they are viable as a high thrust propulsion plant of an interplanetary manned spacecraft using just photovoltaic panels! Furthermore, as Jouni notes above, it's now possible to use them as LANDER engine. That is going WAY too far.

With the previous ion engines, it was similar to real life- **if you got a parts pack that included a nuclear reactor**- then ion engines suddenly became a viable choice for high impulse, large spacecraft propulsion. They were not a viable choice for a lander engine because any electrical system that provided enough power for them would be too heavy to land. Previously in KSP, with only solar panels, you could only use them to propel relatively small spacecraft, or get extremely slow accelerations with larger spacecraft. This is correct to real life.

Not that the previous ion engines were perfect- they worked in an atmosphere, which led to ridiculous things like ion-engine propelled aircraft. IRL, ion engines *REQUIRE* a hard vacuum to operate! Furthermore, the utility of the previous ion engines was greatly reduced by the lack of a nuclear reactor part. IRL, we have been launching nuclear fission reactors into space since the 1960s (the U.S. launched one, the Soviets launched like a dozen).

The CORRECT way to fix this problem was to:

1) Provide a nuclear reactor part (really, a heating/cooling system would also need to be modeled, as IRL, nuclear reactors in space require large heat radiator panels. To do work, you have to have a heat difference, basic thermodynamics...)

2) Provide larger, higher thrust ion engines

3) Provide large xenon tanks.

The INCORRECT way to fix the ion engines is to do what Squad did in fact do- reduce the required power hugely, and increase the thrust hugely. Now, we're going to see ridiculous creations like ion-powered landers (no ion engine or even higher-thrust related technology could EVER land a spacecraft on another body, except maybe on a ***SMALL*** asteroid), and a huge surge of ion-powered aircraft. (The correct way to enable electric-powered aircraft would be to add an electric motor-driven propeller part).

Not that *I* truly care how others play the game, but now I have to go back and mod the ion engines back to a believable balance level. And if you DO care about game balance and are unwilling to rebalance the stock parts yourself, God forbid Squad ever implements larger xenon tanks and nuclear reactors- then NO ONE in their right mind would ever use an LV-N again.

So while I DO understand Squad's desire- make the ion engine a viable option- the solution to that is to add additional parts, NOT make the ion engine ridiculously overpowered, enabling it to be used in situations it can never be used in IRL.

Edited April 9, 2014 by |Velocity|

[SSSPutnik]

AFAIK - Ion engines were never designed IRL with the intent of delivering a multi ton intersystem ship. The goal was an efficient, relatively light weight propulsion system for probes due to the low TWR.

Squad are making it possible to use them for serious payloads and/or landers which is.. wrong.

0.23 ion engines were fantastic for small satellites and probes. Decent acceleration.

A stock nuclear reactor would be nice.

[cantab]

Ion engines have been proposed for big spacecraft. The actual uses thus far have been on small probes, but that stands to reason - engineers are going to use a relatively new technology on a small cheap mission first.