0.23 Whats new?

[egreSS]

Which one is the big code-optimization-pass-through? .24?

[peadar1987]

"EVA uses monopropellant instead of it's own infinite resource."

Alas, alack, welladay!

I can see it now. First Mun landing of my new career mode. Jeb hops down off the ladder. Oh no! All of the monopropellant is in Bob's jetpack from that EVA he did for SCIENCE over the twin craters. Never mind, I'll just get a soil sample from closer by and hop back into the... GRAH! NO LADDER! Jeb is abandoned on the Mun for all eternity because he's 5cm too short to reach the door to the lander.

Edited December 10, 2013 by Vanamonde

[DMagic]

Which one is the big code-optimization-pass-through? .24?

Supposedly that is for this update, 0.23. It was first mentioned a little while before the 0.22 update, and it has been brought up several times in the Tuesday Dailies. Though it won't be too surprising if they continue to optimize things for several updates, or again later on.

[architeuthis]

Does the implementation of tweakables in 0.23 imply that the LV-N will no longer need to burn oxidizer?

[kujuman]

Hmm if that is what srb plugs are that will make things interesting. Can already think of a few ways to improve my designs using variable thrust SRB's.

They are quite handy. Even if they are just a simple implementation of each plug having a set burn time and thrust based on fuel, a lot of good can come from them. Of course, Mechjeb and Kerbal Engineering (as I understand them) are not set up to really support variable thrust within a stage during launch.

Speaking of SRB plugs, allow me to shamelessly plug my SRB mod, which introduces variable thrust curves and segment plugs into SRBs.

[Bothersome]

Are they like real life, once lit they burn till exhausted?

And what are the curves? High power at first and less later or other way around?

[Spatzimaus]

Does the implementation of tweakables in 0.23 imply that the LV-N will no longer need to burn oxidizer?

No, I'm pretty sure that won't happen once the new resource system goes in and they start requiring Nuclear Fuel instead of liquid fuel.

I'm definitely looking forward to this next version, because I've always been a fan of game designers that put some time into debugging and optimization instead of just tacking on even more half-finished features. Sure, you'll always get a few fans who complain about how nothing substantial was added, but it makes the game much better in the long term... if only because it gives you a stable platform on which to add the NEXT round of new features. (Like the aforementioned resource system, which is what I'm REALLY looking forward to.) Besides, I've been making gigantic constructions lately and any performance improvements would make a big difference to me right now.

[Lazro]

NTRs use Hydrogen as the fluid it heats up for propulsion, so it's conceivable that it will just stay as Monopropellant.

[rakutenshi]

Would be neat if they made the tweakables allow different fuel. I.e. you could switch to H2/LOX (Low density, high ISP) for one stage and RP2/NH4 for other stages (more compact, but lower ISP) and have the payload stage back to H2 with an NTR...

[Wheffle]

Super excited for this update...

Edited December 10, 2013 by Wheffle
mix-up

[S4qFBxkFFg]

Wouldn't any fluid (that didn't react with the physical structure) work for the LV-N?

I am thinking that this could be relevant for refuelling away from Kerbin - just add some sort of pump and dip it in the oceans on Eve or Laythe.

(Yes, it's technically reaction mass, not fuel, but I'm assuming the actual fuel mass will be small, even if not negligible.)

[kahlzun]

Wouldn't any fluid (that didn't react with the physical structure) work for the LV-N?

I am thinking that this could be relevant for refuelling away from Kerbin - just add some sort of pump and dip it in the oceans on Eve or Laythe.

(Yes, it's technically reaction mass, not fuel, but I'm assuming the actual fuel mass will be small, even if not negligible.)

Fuel would be whatever you put in, as long as it is liquid, but the heavier the fuel, the lower the Isp. Also, you want to avoid anything with carbon, nitrogen or sulphur as those can attack/lacquer the inside of the engine resulting in Fun.

[Danish_Savage]

Wouldn't any fluid (that didn't react with the physical structure) work for the LV-N?

I am thinking that this could be relevant for refuelling away from Kerbin - just add some sort of pump and dip it in the oceans on Eve or Laythe.

(Yes, it's technically reaction mass, not fuel, but I'm assuming the actual fuel mass will be small, even if not negligible.)

Not really, as pumping random liquids up, would result in some freaky things happening.

[Kerbart]

I am a programmer, albeit not for KSP (unfortunately )

(list of one "big change" and many "small changes")

And that doesn't include any and all bugs which should be solved, because they weren't in this list.

Don't forget, gingercookie, that what seems a small change for somebody not familiar with the codebase might, for some arcane reason, actually be a complete headache to implement. I'm sure you're familiar with that effect.

[longhornchris]

Fuel would be whatever you put in, as long as it is liquid, but the heavier the fuel, the lower the Isp. Also, you want to avoid anything with carbon, nitrogen or sulphur as those can attack/lacquer the inside of the engine resulting in Fun.

Bingo, although there are a few other stipulations to go with it. The NERVA reactor design was a graphite core, so anything that will oxidize carbon is a very bad thing as it will cause the reactor to eat itself. Furthermore, anything that changes the nuclear reaction (strong neutron moderators or reflectors) would make controlling the reaction difficult.

Hydrogen is the best choice but storage is a pain in the ass and hydrogen embrittlement can cause issues with certain metals. For long term storage, water, methane, or other hydrogen rich molecules may work better if they can be electrically or thermally split before being fed to the reactor but you have to do something with the leftovers. Water has the advantage of providing O2 for the crew.

Also, in theory a hydrogen design's exhaust isn't radioactive, barring any tritium production which should be small. Reactor bits that get in the exhaust stream would be radioactive... but if there's a lot of that you've got bigger problems as the engine is eating itself.

Another option besides the NERVA is the molten-salt rocket. Instead of pumping inert reaction mass through a nuclear reactor to heat it the idea is the fuel contains the fissile material along with a lot of inert material that will boil. The thrust chamber is still the reactor. As the fuel is pumped in it goes critical, and is ejected. The design runs much, much hotter than the NERVA design and the exhaust is very, very nasty but its got a really good ISP. Additionally, storage of the fuel can be tricky as you need to keep it from reaching critical mass except when it gets into the engine.

[Stargate525]

Bingo, although there are a few other stipulations to go with it. The NERVA reactor design was a graphite core, so anything that will oxidize carbon is a very bad thing as it will cause the reactor to eat itself. Furthermore, anything that changes the nuclear reaction (strong neutron moderators or reflectors) would make controlling the reaction difficult.

...

Hydrogen is the best choice but storage is a pain in the ass and hydrogen embrittlement can cause issues with certain metals. For long term storage, water, methane, or other hydrogen rich molecules may work better if they can be electrically or thermally split before being fed to the reactor but you have to do something with the leftovers. Water has the advantage of providing O2 for the crew.

Wouldn't water be the most ideal? Split it out, and you send the hydrogen into the engine and the oxygen into the crew compartment. Then, couldn't you shove the 'used' oxygen (in the form of CO2) into the engine as well? Obviously, graphite and all, regular oxygen would lead to Oroborus of the NERVA, but CO2 is already chemically stable.

[longhornchris]

CO2 isn't chemically stable at extremely high temperatures, especially when near carbon. Get it hot enough and you will get carbon monoxide... and the reactor gets damaged.