Developer Insights #17 - Engines Archetypes

[Sir Eskomaz]

6 hours ago, Vl3d said:

I think everyone completely missed this post... Amazing!

PS1: Somewhat related to engines - a quick question. Because we have a few preset diameters and length steps for fuel tanks - can the length be adjustable from the tank properties instead of each fuel tank with the same diameter being a separate part? Not asking for completely procedural tanks, just step-wise for length. It would declutter the part picker list. Same for solid fuel boosters..

PS2: "For their space program, Kerbals have passed over the brutish kerosene, toxic hypergolics and seductive lure of liquid hydrogen..." - does this mean the mentioned fuel types are not going to be in the game? I'm surprised, because Nate mentioned liquid hydrogen as being a fuel type used for the nuclear thermal engines. A little confused..

PS3: Will there be fuel switching for engines, will we have engines that can use multiple fuel types? Is the Vector a methalox engine?

Chris probably meant booster and sustainer engines like an rs-25. Hydrogen is still needed for NTP.

[The Aziz]

1 hour ago, TheTennesseeFireman said:

I’m guessing this is being done with an eye towards the resource system. Methalox makes a lot more sense when it comes to harvesting in situ resources, since you’re far more likely to find methane than kerosene on any given body. And for an average player, the functional difference between Kerolox and Metholox would be so minimal that it’s not worth having a whole extra set of engines for minor performance tuning.

 

Edited December 16, 2022 by The Aziz

[Leha44581]

Another day with nuclear engines still having unrealistically horrible ISP on sea level.

[CobaltWolf]

2 hours ago, TheTennesseeFireman said:

I’m guessing this is being done with an eye towards the resource system. Methalox makes a lot more sense when it comes to harvesting in situ resources, since you’re far more likely to find methane than kerosene on any given body. And for an average player, the functional difference between Kerolox and Metholox would be so minimal that it’s not worth having a whole extra set of engines for minor performance tuning.

Ooooh good point

[Rocketology]

Great write up and makes a lot of sense to standardize under "metholox" fuel type to appeal to a larger player base and let modders get into the nitty-gritty for those seeking hyper realism. And of course those engines shown are drool worthy!

[Navoan]

Great read! Really appreciated. 

[Tangle]

3 hours ago, TheTennesseeFireman said:

I’m guessing this is being done with an eye towards the resource system. Methalox makes a lot more sense when it comes to harvesting in situ resources, since you’re far more likely to find methane than kerosene on any given body. And for an average player, the functional difference between Kerolox and Metholox would be so minimal that it’s not worth having a whole extra set of engines for minor performance tuning.

I mean... why not include hydrolox, then? Surely you're gonna be able to refine ice into, yknow, hydrogen and oxygen for fuel.

Edited December 16, 2022 by Tangle

[RP1IsSuperior]

I'm gonna be honest here.

it looks like the  "methalox is the best fuel combo under any and all circumstances no matter what" mindset is impossible to crush now. I think a major problem with the space community as a whole(KSP community and space community heavily overlap) is the lack of nuance, how one thing is automatically the best for everything. I even fell into this trap myself(look at my username),  although I would like to think I have left it. I used to think density was everything. Now I very much appreciate the value of high energy stages as well as the benefits of hypergolicity. KSP was praised because it taught people to make smart engineering decisions and about the nuance of spacecraft design. Now a huge part of that I feel has been thrown out the window, at least for early game until you get to exotic propulsion.

4 hours ago, ChubbyCat said:

So is the Mammoth II replacing the original mammoth, or will they exist alongside each other? It would be only slightly disappointing to not be able to create accurate SLS recreations anymore. 

I think it's getting thrown out the window. It's very clear what the KSP 2 devs are inspired by, and they're very attracted to futurism. It does look like the F-1B though(my beloved) so that's kind of a plus?

[Xelo]

53 minutes ago, Leha44581 said:

Another day with nuclear engines still having unrealistically horrible ISP on sea level.

Wut, didnt the graph say they have a high ISP at sea level but bad TWR? Id also image the trend with nuclear engines continues somewhat into the higher isps not shown in the graph too. 

[Guest]

9 minutes ago, RP1IsSuperior said:

it looks like the  "methalox is the best fuel combo under any and all circumstances no matter what" mindset is impossible to crush now. I think a major problem with the space community as a whole(KSP community and space community heavily overlap) is the lack of nuance, how one thing is automatically the best for everything. I even fell into this trap myself(look at my username),  although I would like to think I have left it. I used to think density was everything. Now I very much appreciate the value of high energy stages as well as the benefits of hypergolicity. KSP was praised because it taught people to make smart engineering decisions and about the nuance of spacecraft design. Now a huge part of that I feel has been thrown out the window, at least for early game until you get to exotic propulsion.

Well, part of the problem is that KSP glosses over so many of the problems you encounter in spaceflight, like long-term fuel storage (something that hypergolics are perfect for). So naturally that midpoint methalox will look very attractive while ignoring the strengths of heavier or lighter molecules coming out the back end. c'est la vie.

[Meecrob]

1 hour ago, The Aziz said:

 

To add, I mean they literally said they are making the game accessible to modders, and this is early access. I imagine a bunch of devs thinking "but..but...you guys mod it anyways and we told you this isn't the final product"

 

Full disclosure, I have a bunch of issues with KSP2 I'm worried about, but this is pretty lame. If anyone thinks there won't be mods for fuel types, I dunno what to say.

[desert]

Liquid fuel had to be named, but it's a bit disappointing that it is not kerosene. I understand why it is simpler for the new players to have a single type of chemical fuel, but it really affects historical and physical realism, and visual and gameplay diversity. We will now have purple-only plumes for every engine, and we will have methane planes.

Choosing LF vs LH from Cryogenic Engines was an interesting engineering trade-off. And it also teached players that there are different types of chemical fuels with different pros and cons. Also, unlocking LH engines was a rewarding step in one's progression. I really hoped it will be implemented in KSP 2, especially with Nertea being in a dev team.

If I understand correctly, we now have nuclear thermal engines that will be hydrogen-only, and all chemical engines will be methane-only. And we won't have fuel switch, cryogenic tanks would be for hydrogen only, standard tanks will be methane-only. And as I hear it, we won't have have several engines in single niche, which was good for replicas and craft fine tuning. If you need 1.25 orbital engine, for your lander, you will only have Terrier. There won't be Pug or Cheetah or anything else.

Yes, it will be much simpler, but I feel like it throws us back to very first KSP-1 versions, with engine configs being named by size and not name, crossing out things we got since then, such as multiple distinctive parts from the same category, fuel switch, various plumes etc.

Anyway, thanks for the post. Besides fuel decision, it was informative and it shows that devs have coherent vision, even of I disagree with something 

[desert]

3 hours ago, TheTennesseeFireman said:

I’m guessing this is being done with an eye towards the resource system. Methalox makes a lot more sense when it comes to harvesting in situ resources, since you’re far more likely to find methane than kerosene on any given body.

It could still work if we had kerosene and hydrogen. There would be some interesting decisions for the player when planning the flight. "Do I make cheap compact lander which I can't refuel, or do I make bulky hydrogen lander with ISRU?"

Kerosene synthesis could still be implemented, but limited by resources available in the colony and the need to use more advanced or heavy equipment. For example you would have hydrogen producing bases on the moons and kerosene producing bases on atmospheric planets.

As for kerosene and methane difference being minimal, same can be said about methane and hydrogen. But if you compare kerosene and hydrogen, the difference is significant. And now we won't experience it (without mods or course)

 

[Nate Simpson]

A couple of clarifications:

Methalox was chosen as our default fuel to serve the colony progression: ISRU is a major component of the midgame, and we felt that methalox was the best all-purpose fuel to speak to the harvesting->fuel creation pipeline (if you look at the details of our colony methane fuel factory, it's got Sabatier reactors, water electrolyzers, CO2 condensors, etc.). We're hoping, as usual, that if a person is interested in the process being demonstrated, they can hit Wikipedia and learn some cool stuff. 

Second, we haven't talked much about it, but +1 to the folks above who have pointed out that there will be another new fuel present for day one of Early Access: liquid hydrogen. When you see gold foil on tanks in any capture footage, that's what that is. The NERV and SWERV engines run on hydrogen.

[desert]

5 hours ago, ChubbyCat said:

So is the Mammoth II replacing the original mammoth, or will they exist alongside each other? It would be only slightly disappointing to not be able to create accurate SLS recreations anymore. 

I think it's pretty much fixable with the right adapter and four Vectors. And if the adapter is switchable, you could even make six engined SLS or some other kind of monstrosity.

[Guest]

10 minutes ago, Nate Simpson said:

Second, we haven't talked much about it, but +1 to the folks above who have pointed out that there will be another new fuel present for day one of Early Access: liquid hydrogen. When you see gold foil on tanks in any capture footage, that's what that is. The NERV and SWERV engines run on hydrogen.

Please tell me we're getting fuel switching tanks so I'm not locked into one "look" for my spaceships (not to mention scrolling for days through the list trying to figure out which tank is which)

Edited December 17, 2022 by regex

[RP1IsSuperior]

13 minutes ago, Nate Simpson said:

A couple of clarifications:

Methalox was chosen as our default fuel to serve the colony progression: ISRU is a major component of the midgame, and we felt that methalox was the best all-purpose fuel to speak to the harvesting->fuel creation pipeline (if you look at the details of our colony methane fuel factory, it's got Sabatier reactors, water electrolyzers, CO2 condensors, etc.). We're hoping, as usual, that if a person is interested in the process being demonstrated, they can hit Wikipedia and learn some cool stuff. 

Second, we haven't talked much about it, but +1 to the folks above who have pointed out that there will be another new fuel present for day one of Early Access: liquid hydrogen. When you see gold foil on tanks in any capture footage, that's what that is. The NERV and SWERV engines run on hydrogen.

The ISRU bit makes sense, but only for Duna, and possibly Laythe. Mars and Titan are really the only place where you can obtain methalox through ISRU. The baseline ISRU is usually hydrolox. Other fuels like Ammonia also fall into the same sort of category in terms of how easy they are to produce in situ.

[Bej Kerman]

Something obvious that KSP 1 never had was the ability to sort engines by thrust and isp. If you need to find an efficient one, you have to dig through each one to find the best atmo or vac efficiency. This just gets worse the more mods you add.

[Xelo]

13 minutes ago, RP1IsSuperior said:

The ISRU bit makes sense, but only for Duna, and possibly Laythe. Mars and Titan are really the only place where you can obtain methalox through ISRU. The baseline ISRU is usually hydrolox. Other fuels like Ammonia also fall into the same sort of category in terms of how easy they are to produce in situ.

Well isnt Duna typically the first planet you go to? From a gameplay perspective it would make sense for the early game planets to source early game fuels like methalox. And later, most distant planets rich in water ice to fuel hydrolox/ nuclear thermal engines. 
 

[TheTennesseeFireman]

43 minutes ago, RP1IsSuperior said:

The ISRU bit makes sense, but only for Duna, and possibly Laythe. Mars and Titan are really the only place where you can obtain methalox through ISRU. The baseline ISRU is usually hydrolox. Other fuels like Ammonia also fall into the same sort of category in terms of how easy they are to produce in situ.

Eve isn’t a direct 1-1 Venus comparison, and it may well have a heavy hydrocarbon concentration in its atmosphere, as methane is after all a powerful GHG. Regardless, how many places do you really need methalox ISRU in the Kerbin system? Kerbin presumably has an unlimited amount, and the availability of resources is meant to be a different challenge from planet to planet. By the time you’ve reached the Jool system, you’ll probably have unlocked liquid hydrogen ISRU on the tech tree and be able to take advantage of that instead.

[Minmus Taster]

[SolarAdmiral]

5 hours ago, Sidneyia said:

Hear me out: don't do this. Don't add these labels to the engine description.

I disagree. I love the look of this. One, it's been a major stumbling block every time I've tried to get someone else into ksp. For the first dozen rockets they try to build, every stage they select several before finding one that's right. They know what they're looking for, a rocket that 'feels' like the right size for what they're building. But can't tell which one it is just from looking at all the rockets listed in the menu. It causes them lots of frustration and some put the game down for a while. And two, I'm looking forward to being able to sort them by these categories when I'm building too.

[The Aziz]

A lot of people seems to be upset about something as trivial as name change. Bet they wouldn't mind if KSP2 had Liquid Fuel, Cool Liquid Fuel, and Super Fuel.

[Xelo]

I wonder, Is solid fuel going to have a 'real-chemical' name as well? :O 

[Kerbart]

8 hours ago, WarriorSabe said:

I, hm. Methalox for all of them? That really doesn't... make sense. The diversity of engines being adapted at the very least should have some be kerolox

Be  bit creative. If anything, we want engine to run on Kerbosine instead...