Tweakable fuel tanks

[Firov]

Psycix, just because they share the same tooling doesn't mean that Space X can just rip the guts out and change the internal structure of their tanks willy nilly. They would probably need to sit down and go through the design process all over again and adjust the tooling to build the proper cylinder side lengths. Let's not forget they'll need to calculate and build properly sized expanders for the nitrogen or helium vessels that will maintain tank pressure. The advantage to their system is that they don't need separate production lines/facilities for each tank or can reshuffle production if machines on one of the tool sets are broken. That's a step towards the standardization route, not the custom innards route.

Okay. I'm going to assume you didn't read my last post to you. However, rather than post it again...

That's what we're talking about. When we're sitting in the VAB or the SPH we're in the "design process", as you put it. As such, there's no reason we shouldn't be able to alter the internal geometry of the tanks. No space agency is going to "design" a rocket that's got a large empty tank that they have no use for. It's a waste of mass and a waste of volume. Truly, no self respecting engineer is going to intentionally design in a large empty tank that they don't plan on using, and indeed, any attempt to do so would likely result in said engineer ending up on the food line where he can't do any more damage.

We're not talking about altering tank geometry in flight, that would be ridiculous. We're talking about altering the base design of the craft before it's constructed, which is not just plausible, but quite realistic.

Edit - Just think about it for a moment... What's more likely in this scenario. Option A or Option B?

At NASA in the '60s, engineers are gathered around in a smoke filled room to discuss their greatest challenge yet. Designing a rocket that can lift the 4,050 pound Apollo missions into orbit. They nervously glance at one another after their latest series of calculations show that they won't be able to manage the required delta-V with the current design. They know the whole country is counting on them, and that they can't afford to fail here. Suddenly, from the back of a room comes a suggestion. "Hey guys, I have an idea! Lets throw in a big empty tank that we won't use!" The room falls silent. All of the other engineers face towards the originator of the idea, it's Alan the intern. The lead engineer's jaw falls open, his cigar falls onto the floor, still smoking.

A. Suddenly, there's widespread cheering and applause. The engineers pick up Alan and carry him to the nearest bar to celebrate by buying him a round of drinks.

B. The lead engineer immediately picks up the phone and calls for security to remove Alan from the building for suggesting such a ridiculous idea in the first place.

Edited December 14, 2013 by Firov

[Tw1]

I prefer having specialised fuel tanks. Different fuels have different properties, and need to be stored different ways. It adds realism to me.

[Albert VDS]

Let's put it this way. It's called tweakables, not modular fuel tanks.

If a garage tweaks your car's engine, then they don't change it from a gasoline engine to a diesel engine.

They might change the fuel flow or some other minor adjustment.

[chuangatronic]

Oh boy what a fun read...

Lets address a couple preconceived notions about the VAB/SPH from both perspectives...

A) A user thinks the VAB/SPH is a magic box to fulfill their design whimsy. This is pretty much what every space agency does since the design engineers have no need to worry about part availability or design restrictions or manufacturing constraints (to a sane level).

A user thinks that the VAB/SPH is like a custom ship akin to OCC or Gas Monkey Garage where they take off the shelf components to build customized rockets within a range of specifications. A shop like this is full of design constraints since it uses only standardized parts.

Now let's look at the definition of tweaking. Tweaking by definition is the fine tuning of a system such as adjusting the throttle cable on the car or tire pressure in the tires. If you look at it that way, you can't tweak fuel capacity or fuel type of an already built tank; doing so would be incurring a major engineering change. Replacing liquid fuel with LOX would have to change the expander, cryogenic systems, etc. along with tank sizes.

With the scope of tweaking in mind, it's easy to see the difference in degree between the mindsets of A and B. A is a design house, changing the fuel for the tank is just changing a number. This falls within tweaking semantically since it's just tweaking numbers before anything is sent to manufacture. The problem with this is that A has a severe level of abstraction that forgoes any engineering related to the fuel type, which is okay for project managers and system level engineering, but makes it a potential nightmare for component level engineering; a tweak of this level might mean redoing all your work. B is a custom assembly house, tweaking fuel capacity of a single fuel cell is impossible for B. The only way to manage this is to request a custom part or add more tanks to fit the need. As or right now, the VAB/SPH very much represents B in gameplay but has potential to be A (which it should strive for to a degree). Mods like Procedural Wings and Stretchy Tanks make the build process much closer to A but the nature of the game will likely stay in the realm of B to keep the barrier learning curve low enough for casual players. I think that something along the lines of Stretchy Tanks is perfectly feasible for stock game play, but that doesn't really fall under the title "tweakable".

BTW: I very much would like procedural tanks over our current piecemeal design, but I am also very much aware procedural tanks is very far from what "tweakable" is or ever will be.

Edited December 14, 2013 by chuangatronic

[Toshogu]

That seems to work backwards. Say I need a tank full of liquid fuel for an airplane. That leaves me with only the pure liquid-fuel tanks to really choose from. Sure, I could remove the oxidizer from a bipropellant tank but that leaves me with a rather lot of dry weight compared to the amount of fuel I'm bringing. If I want to build an oxidizer tanker where SSTOs can top off for interplanetary flights, same problem. Allowing full customization of a tank's contents would allow me to use any tank for any purpose. Volume and shape would then become the deciding factor, rather than pre-programmed compartments.

In terms of coding and user-friendliness the main stumbling block would likely be the odd ratio of liquid fuel and oxidizer that's used by rocket engines. The simplest fix for that is to change the LF/OX consumption ratio to 1:1. That, of course, would take some elbow grease in reconfiguring all rocket engines and fuel tanks, but in the end it would greatly simplify fuel tank logic: Tank holds up to X units of resources, fill as you please. For realism's sake, an individual tank's max values per resource could be set once the craft is moved to the launchpad/runway: no re-compartmentalization on the fly.

so basically what you want is Kerbal on Easy/Godmode/dumbed down.

Leave the stock game as they see it so far. It's realistic enough to keep the sims happy, and easy enough for everyone else.

If you want the game easier than what it is now, that's what MODs are for. I'm sure someone has a mod out there that completely overhauls the engines or gives you a bunch of OP engines, and procedural fuel tanks that will eventually be tweakable to the point of broken. Till then just leave KSP headed in the direction it is going, one of the few games being made that still takes a bit of brain power to play.

[GusTurbo]

so basically what you want is Kerbal on Easy/Godmode/dumbed down.

Leave the stock game as they see it so far. It's realistic enough to keep the sims happy, and easy enough for everyone else.

If you want the game easier than what it is now, that's what MODs are for. I'm sure someone has a mod out there that completely overhauls the engines or gives you a bunch of OP engines, and procedural fuel tanks that will eventually be tweakable to the point of broken. Till then just leave KSP headed in the direction it is going, one of the few games being made that still takes a bit of brain power to play.

I don't think you understand the other side of the argument. Filling different tanks with different things wouldn't make the game any easier, or dumb it down. For example, if you were making a rocket, you would still need liquid fuel and oxidizer. Filling one tank with only liquid fuel would still mean you would need another tank with oxidizer. No one is arguing for a "Godmode" where you can fill a small tank with a disproportionate amount of fuel. Even if people were asking for procedural tanks, that wouldn't be overpowered -- fuel still has mass, and the dry mass of the tanks would still scale with size. The only way your argument makes sense is if fuel (or tanks) have no mass.

[I_Killed_Jeb]

Why can't people see/understand that some of us want to build the spaceships that we want? We just want the game to enable us to make the things that are in our heads. I don't see how this is "godmode," as we're actually asking for advanced abilities. Much like NASA, I'd love to build ships with razor thin margins as opposed to having a bunch of overbuilt (awesome) monstrosities. This takes calculation and troubleshooting and all the stuff that makes me feel like a cool rocket scientist.

[Audiopulse]

Why can't people see/understand that some of us want to build the spaceships that we want? We just want the game to enable us to make the things that are in our heads. I don't see how this is "godmode," as we're actually asking for advanced abilities. Much like NASA, I'd love to build ships with razor thin margins as opposed to having a bunch of overbuilt (awesome) monstrosities. This takes calculation and troubleshooting and all the stuff that makes me feel like a cool rocket scientist.

Because this isnt ponyland where you get your wishes granted as they come. KSP is the way Harvester makes it - if bits of the game dont follow your perception of how you see fit, well, then you can either manage or not buy the game in the first place.

That sounded harsh and its most certainly not satisfying for you to hear, but you totally disregarded the reality and simply stated 'what you want'. And sadly, youre in good company with that. For some time now the perception has shifted and there are those who see the game as theirs, while actually Kerbal Space Program is Harvesters brainchild and only his. Paying the price allows you and everyone else, including me, to play KSP, but we do not own the Project. KSP will always be different from what we wish it to be, because to be perfect everyone would have to code it for himself to suit his unique needs.

Now, of course there is nothing wrong with stating what one wishes, however, the last decision lies in squads hands. And that has to be respected.

[zekes]

what about one slider, and when you move it one way fuel increases and oxidizer decreases? and vice versa?

[iDan122]

what about one slider, and when you move it one way fuel increases and oxidizer decreases? and vice versa?

You have to sliders: oxidizer and liquid fuel(in a rocket fuel tank).

Those sliders are independent from each other, you can make liquid fuel 75 and oxidizer 20 percent or 50 and 50 or 0 and 0 and so on....

[Wayfare]

so basically what you want is Kerbal on Easy/Godmode/dumbed down.

Please don't quote me out of context. I was responding to regex' suggestion that limiting different fuel tanks to different types of resource would add incentive to use different parts. I think it works the other way around - right now if you want to put RCS on your craft, you have to use a predefined RCS tank. If you could pick any tank you want and then fill it with monopropellant, you have a wider choice of parts you can use for that purpose.

[Firov]

Because this isnt ponyland where you get your wishes granted as they come. KSP is the way Harvester makes it - if bits of the game dont follow your perception of how you see fit, well, then you can either manage or not buy the game in the first place.

That sounded harsh and its most certainly not satisfying for you to hear, but you totally disregarded the reality and simply stated 'what you want'. And sadly, youre in good company with that. For some time now the perception has shifted and there are those who see the game as theirs, while actually Kerbal Space Program is Harvesters brainchild and only his. Paying the price allows you and everyone else, including me, to play KSP, but we do not own the Project. KSP will always be different from what we wish it to be, because to be perfect everyone would have to code it for himself to suit his unique needs.

Now, of course there is nothing wrong with stating what one wishes, however, the last decision lies in squads hands. And that has to be respected.

Interesting. I don't feel like going through your entire post history, but luckily, I don't have to. So was this also your opinion when you asked Fractal_UK to integrate his Interstellar mod with Kethane? Surely you realized that was HIS mod and that you were just using it. Where was your "manage or don't use" attitude then?

Now, if you were simply making an observation and suggesting a possible improvement, as many of us in this very thread are doing, I guess that's different. But if that's the case, then your little reaction to "I_Killed_Jeb"'s post is a bit harder to explain. You see, you're no different from him, or me, or any of the other people who have suggested possible improvements to something they don't directly manage. So go ahead and climb down off that high horse and join the rest of us down here in the dirt and mud.

You see, everyone here has an interest in KSP and it's future, and I seriously doubt anyone think's they have some form of psychic control over Harvester. And contrary to your little outburst, I've not seen anyone "demand" anything of harvester. Some people have expressed disappointment, but that's different. No. People are simply suggesting a feature that they feel would improve KSP, and you know what, until the moderators go rabid and start banning people for it, they have that right, just as you did in the Interstellar mod thread.

Edited December 14, 2013 by Firov

[zekes]

If you could pick any tank you want and then fill it with monopropellant, you have a wider choice of parts you can use for that purpose.

couple that with D/V indicators like KerbalENgineer and you can make very fine-tuned missions, with the most eficcient possible ships

[I_Killed_Jeb]

Because this isnt ponyland where you get your wishes granted as they come. KSP is the way Harvester makes it - if bits of the game dont follow your perception of how you see fit, well, then you can either manage or not buy the game in the first place.

That sounded harsh and its most certainly not satisfying for you to hear, but you totally disregarded the reality and simply stated 'what you want'. And sadly, youre in good company with that. For some time now the perception has shifted and there are those who see the game as theirs, while actually Kerbal Space Program is Harvesters brainchild and only his. Paying the price allows you and everyone else, including me, to play KSP, but we do not own the Project. KSP will always be different from what we wish it to be, because to be perfect everyone would have to code it for himself to suit his unique needs.

Now, of course there is nothing wrong with stating what one wishes, however, the last decision lies in squads hands. And that has to be respected.

Who the heck is asking for ponyland? This is a game about building spaceships. As such, it's not an insane pie in the sky thought to want to build spaceships. How is it disregarding reality to say it'd be cool to fill the tanks how we see fit? If I were managing a space program I sure as heck won't be taking off-the-shelf parts, duct tape them together and cross my fingers.

Of course I'm stating what I want, why else would we be talking on a forum? I don't own the project but I've certainly bought into it, I'm not even remotely saying I should have a say in its development but I live in a country where I'm free to voice my opinions on matters as I see fit. I don't have to respect anything anyone does, including Squad. Now, that doesn't mean that's the case; I very much enjoy KSP and I'm willing to wait and see what happens with the vast majority of future KSP developments, but just because they do something doesn't mean any of us should agree with it. And if we don't, we can simply stop playing and recommend to others that they do the same. This obviously is not a good thing for the devs, which comes back to why they bother to listen to us in the first place.

I'm confused as to why you end your post with the statement that there's nothing with stating one's wishes when your entire post is about how one should not dare express his wishes on something he doesn't own.

[LethalDose]

what about one slider, and when you move it one way fuel increases and oxidizer decreases? and vice versa?

This would be a vast improvement over what is currently implemented and the bare minimum that I would expect from the "feature".

[I_Killed_Jeb]

This would be a vast improvement over what is currently implemented and the bare minimum that I would expect from the "feature".

Most likely it'll be improved and I bet in a couple updates we'll get exactly the kind of detailed customization some of us are hoping for. Squad has a good track record so far of polishing things as they go.

[Superfluous J]

what about one slider, and when you move it one way fuel increases and oxidizer decreases? and vice versa?

Why not 5 sliders, one each for O2, LF, SF*, MP, and Xe? And an ability to add more for Kethane et al?

*Okay SF is probably not needed on regular tanks but hey.

EDIT: And a checkbox to lock LF/O2 to the correct ratio for normal LF rockets.

[Guest]

Who the heck is asking for ponyland? This is a game about building spaceships. As such, it's not an insane pie in the sky thought to want to build spaceships. How is it disregarding reality to say it'd be cool to fill the tanks how we see fit? If I were managing a space program I sure as heck won't be taking off-the-shelf parts, duct tape them together and cross my fingers.

Believe it or not, that's pretty much what Russian and early American space programs consisted of. Russians were all about reusing and upgrading existing components, and Americans made Saturn I first stage from 8 Redstone tanks and a Jupiter 1st stage, while the second stage was basically a 6-engined Centaur. Look at Atlas and Delta evolution, too, especially early versions.

Though, on the other hand, Americans did make new, custom fitted parts for every rocket later on. That should work more like a StretchySRB mod, though. Doing it, however, would always be more expensive than using ready-made parts. Why do you think Soyuz and Atlas lasted so long? Cheap and reliable, that's why. On the other hand, it was Saturn V, not N1, that put humans on the Moon, so when you need to maximize performance, custom-fit is the key.

[Audiopulse]

Who the heck is asking for ponyland? This is a game about building spaceships. As such, it's not an insane pie in the sky thought to want to build spaceships. How is it disregarding reality to say it'd be cool to fill the tanks how we see fit? If I were managing a space program I sure as heck won't be taking off-the-shelf parts, duct tape them together and cross my fingers.

Of course I'm stating what I want, why else would we be talking on a forum? I don't own the project but I've certainly bought into it, I'm not even remotely saying I should have a say in its development but I live in a country where I'm free to voice my opinions on matters as I see fit. I don't have to respect anything anyone does, including Squad. Now, that doesn't mean that's the case; I very much enjoy KSP and I'm willing to wait and see what happens with the vast majority of future KSP developments, but just because they do something doesn't mean any of us should agree with it. And if we don't, we can simply stop playing and recommend to others that they do the same. This obviously is not a good thing for the devs, which comes back to why they bother to listen to us in the first place.

I'm confused as to why you end your post with the statement that there's nothing with stating one's wishes when your entire post is about how one should not dare express his wishes on something he doesn't own.

You know what? Youre right - I made you the display of what was troubling me with certain attitudes I experienced around the forum lately while your comment was a lot more harmless than it ocurred to me last night. There is a group of people acting like I described and one of those made a rather idiotic demand in this very topic. It got me angry enough to fire my missiles at the wrong person. My apologies for that.

(...) I don't feel like going through your entire post history, but luckily, I don't have to. (...)

I think its rather creepy youre going through my Forum-history just to formulate a good comeback. Dont do that.

Edited December 15, 2013 by Audiopulse
cosmetics

[Flowz0r]

Don't get me wrong, I absolutely love every change and addition in .23, the science changes make career mode a lot more challenging and enjoyable, the RAPIER engine is absolutely genius, and the tweakables-system is for the most part as good as or better than I expected. There's one thing about it that made me just a little sad, though.

It doesn't seem to be possible to fill any of the tanks with a combination of fuel of your choosing, it merely lets you remove some fuel before launch. I was under the impression that we'd be able to, for example, fill a large orange fuel tank with xenon if we really want to for some reason, which doesn't seem possible right now. It pains me to be forced to take a fuel tank into space with my SSTO spaceplane that's only 2/3 filled with fuel, since I won't be needing most of the oxidizer and there's no way to fill the empty portion with liquid fuel.

Is this working as intended and won't be expanded upon, or will we be able to do what I described at some point in the future?

/Edit: Thanks for merging my thread into this, mods. Kind of missed this one.

Edited December 18, 2013 by Flowz0r

[Retread]

Lots of discussion on this subject here.

[lajoswinkler]

We had the exact same thread few days ago and it turned into a sort of fight.

Yes, it is intended to be like that because that's how the fuel tanks work. There has to be a line drawn somewhere.

[Themohawkninja]

The whole concept of allowing users to have an orange tank's worth of xenon fuel (or any other absurd amount of fuel using orange tanks), while nice, only really serves two purposes: (1) Reducing part count, and (2) reduce drag. The latter of these two should be moot when the aerodynamics gets updated, and as for the former, you are only saving (going along with the Xenon example, and assuming you could replace all fuels in a 1:1 ratio) a bit over eight parts (6400/700=9.14..., subtract one to account for the orange tank).

Not to mention the fact that an orange tank takes up a lot more volume than nine xenon tanks would.

All that being said, I do wish that we could replace all of the oxidizer with liquid fuel, or visa versa, instead of being limited to a half-full tank so-to-speak.

[BubbaWilkins]

I think the current implementation is just fine.

It seems counter productive to introduce a super configurable tank which then eliminates all other tanks by virtue of flexibility. At least now you have the option of dropping any excess weight (surplus oxidizer) should you be so inclined.

It also seems like a poor craft design choice to launch an empty tank. If the tank isn't carrying fuel for the mission, it's dead weight which would require a second tank to carry the fuel to to launch it in the first place. Then you have to have some sort of method for filling it up later. Why not just use an empty structural fuselage in the first place and be done with it?

[Psycix]

(1) Reducing part count, and (2) reduce drag

(1) Is always a very good reason to do something. I don't agree with your assumption, I think one would be able to fit a lot more xenon in there, as the xenon shouldn't replace the liquidfuel 1:1 in volume.

(2) This is incorrect, drag is dependent on mass. Ten 1 ton tanks have as much drag as one 10 ton tank.