Why isn't delta-v exposed in Stock (yet)?

[eightiesboi]

[/rant on] First, I've been playing KSP since .25, so I *have not* been here since the beginning, but I have been around for a little bit of time. I have over 1700 hrs tracked in-game, but I usually play heavily modded games with KCT included, and I tend to run multiple missions *without* time acceleration, so my tracked hours aren't representative of time I've spent actually PLAYING (that's honesty for you).

Now that that's out of the way...

Of all the mods I use, there's one (and only one) that I can't understand why it (or something like it) isn't already in the game, and that's Kerbal Engineer Redux (KER). Kerbal Space Program is about sending things (frequently rockets) into space. Without knowing how much delta-v a vessel has, along with things like TWR, etc, you don't know whether a vessel will make it to space, or the Mun, or New Caprica, or whatnot. Seriously, for people that play ENTIRELY in stock, how do you deal with this? Do you just massively over-engineer your rockets? Do you send up rocket after rocket, hoping you will make it to orbit? I simply don't believe it is possible to run KSP in career mode unmodded and have an actual space program without this information. In fact, when I have given KSP as a gift, the first thing I do is tell the recipient to download KER.

I feel that Squad missed the boat with the latest update. Yes, I obviously know mods like KER (and others) exist--like I said in the beginning, I play a heavily (180+ installed) modded game. But there are two groups of people that Squad should think of when they consider the next update, patch or whatnot. First there are the new purchasers of KSP, who try to play a stock game before they realize they have three options that don't involve modding: over-engineer every rocket (difficult in early career mode), engage in constant trial-and-error (also difficult in career mode), or work out the equations for every rocket they want to launch. These people will either get frustrated and quit playing or go install some mods, and then the fit into the other group of people....

Speaking of that other group (all of us that use some mod to give us the dV info that Squad doesn't provide), the reason why *we* AND Squad should care about stock dV, is that modders work for free, and frequently in whatever spare time they have. Tomorrow, @linuxgurugamer (who is maintaining over 100 mods), @DMagic, @Galileo, @magico13, @Nertea, @Starwaster or any other member of our prolific and amazing modding community, could decide they are done modding this game. In the past, modders like LGG have stepped up to continue much-loved (or needed) mods, but especially in light of the changes in licensing that some modders have made, this makes reviving abandoned mods potentially more problematic than in the past. In other words, KSP is really reliant on modders to provide information that is vitally necessary for a successful space program, and really shouldn't be. And while there are many mods that I wish were stock, I think the functionality KER (and the mods like it) provides is absolutely essential.

Those of us who run heavily modded games owe a lot to these modders for making our games more fun, more realistic, more difficult, and more fun (again). (And if you haven't at least treated your favorite modders to at least a cup of coffee, consider doing so--they do a lot for very little). However, we (and Squad) shouldn't have to rely on modders for access to basic information. Or, to put it another way, it's true that if Squad put dV info into the VAB (and elsewhere) I would probably continue to use KER (because I like it; I'm used to it; etc) but if Cybutek left modding and no one took up KER, without dV being provided in stock, I would probably stop playing KSP and I doubt I could recommend purchase to anyone else. Please, Squad, roll in a dV readout in the VAB and SPH (at least). Your customers, new and old, will probably appreciate it.   [/rant off]  

(PS - I called out certain mod makers to make a point; if I were to list all of the individuals who have contributed so much to this game, it would fill the page and still not be enough. There are only two games out of some 200 I own [on Steam] that I play heavily modded versions of--KSP and XCOM 2. As much as I love KSP, I would have quit in .90 if it weren't for all of the modders and their hard work. Every member of Squad and every player of KSP owes a lot to the modders.)

PPS - Apologies to @cybutek! I accidentally deleted you from credit for KER when I originally posted! Thanks to @Starman4308 for bringing this to my attention!

Edited March 11, 2018 by eightiesboi
Credit to cybutek restored.

[klesh]

Hey, those Apollo recreations in the new Making History DLC will be super historical with that classic NASA approach of "just wing it and see what happens" to dV calculation:

 

Edited March 11, 2018 by klesh

[ndiver]

I wonder the same, for the same reasons.

And you can see that there is a "small" problem on this point when all the preview videos concerning Making History have the same mod already installed: KER

[Rocket In My Pocket]

I've always imagined a stock Dv readout using a bar graph or similar pictographic representation as opposed to actual numbers.

I think the reservation about putting a Dv read out in the game in the first place was a fear of scaring off new players with too many numbers.

So maybe something more abstract like the reputation bar? Where the exact actual number isn't important but it gives you a general feeling for where you stand.

[HebaruSan]

35 minutes ago, eightiesboi said:

Seriously, for people that play ENTIRELY in stock, how do you deal with this? Do you just massively over-engineer your rockets? Do you send up rocket after rocket, hoping you will make it to orbit?

No, none of that. Here's what I've been doing recently:

1. Build your payload in the VAB
2. Check its mass with the engineer's report thing
3. Choose a vacuum engine with close to (total mass in tons * 30) kN of thrust, or a bit less if you're willing to tolerate low TWR
4. Attach it, with NO fuel, and check the new total mass in case it's a heavy engine
5. Find a combination of fuel tanks that equal that mass and put them between the payload and the engine (so you're doubling the mass by adding fuel)
6. Congratulations, your craft now has around 2000 m/s of delta V plus a small surplus (since your wet mass is twice your dry mass, and 340*9.81*ln(2) ≈ 2300)
7. Repeat the process with the current craft as your "payload" to continue adding as many blocks of 2000 m/s delta V as you need
8. For SRBs or other engines with low specific impulse, attach twice as much fuel in step #5 instead of an equal amount (tripling the total mass)

It's not too bad. Getting to orbit is roughly two 2000 m/s blocks; orbiting Mun and returning is roughly three; landing on Mun and returning is roughly four; and so on. Parallel staging is more complicated, of course, but it's still do-able by more or less the same procedure if you're willing to juggle a few more figures at a time.

I also like KER, but I've found this method to produce reasonable results without having to break out a calculator. Yes, it relies on the rocket equation, but I only had to evaluate it one time for all my stages.

Edited March 11, 2018 by HebaruSan

[Starman4308]

I think part of the issue is that sometimes, strange staging arrangements can throw delta-V calculators for a fit. For a mod, that's no problem: Sarbian and Cybutek* try, but if you come up with something strange like a probe that uses ion engines to get around the Jool system with chemical engines used for landing, you may be able to break the delta-V calculator. If you're a modder, no sweat, you just tell the person "I'm sorry, I'm not going to handle your egregiously complicated case; go break out a calculator". For Squad, if they put a feature in, they have to support it.

*Is it Cybutek? I know Sarbian manages MechJeb, but I'm not up-to-date on KER.

There's also the element that Harvester's original vision was for a trial-and-error style. I disagree with that notion, but I'm not the lead programmer for KSP.

[eightiesboi]

6 minutes ago, HebaruSan said:

No, none of that. Here's what I've been doing recently:

1. Build your payload in the VAB
2. Check its mass with the engineer's report thing
3. Choose a vacuum engine with close to (total mass in tons * 30) kN of thrust, or a bit less if you're willing to tolerate low TWR
4. Attach it, with NO fuel, and check the new total mass in case it's a heavy engine
5. Find a combination of fuel tanks that equal that mass and put them between the payload and the engine (so you're doubling the mass by adding fuel)
6. Congratulations, your craft now has around 2000 m/s of delta V plus a small surplus (since your wet mass is twice your dry mass, and 340*9.81*ln(2) ≈ 2300)
7. Repeat the process with the current craft as your "payload" to continue adding as many blocks of 2000 m/s delta V as you need
8. For SRBs or other engines with low specific impulse, attach twice as much fuel in step #5 instead of an equal amount (tripling the total mass)

It's not too bad. Getting to orbit is roughly two 2000 m/s blocks; orbiting Mun and returning is roughly three; landing on Mun and returning is roughly four; and so on. Parallel staging is more complicated, of course, but it's still do-able by more or less the same procedure if you're willing to juggle a few more figures at a time.

I also like KER, but I've found this method to produce reasonable results without having to break out a calculator. Yes, it relies on the rocket equation, but I only had to evaluate it one time for all my stages.

First, speaking of modders that keep the community going, thank you.

I know I only had over-engineer and trial-and-error where you quoted, but I include equations further down. Your method is a combination of roughly doing the math and over-engineering, coupled with long experience (and you imply that you still make use of KER). Of course, I don't have the sales numbers and demographics for customers of KSP, but I doubt that many gamers purchase it with the idea that they will get to roughly estimate rocket equations. Again, I am not saying it *can't* be done, but I am saying that Squad relying on modders to fill this hole in particular is a poor practice.

[klgraham1013]

15 minutes ago, Rocket In My Pocket said:

I think the reservation about putting a Dv read out in the game in the first place was a fear of scaring off new players with too many numbers.

It's a good thing they didn't put those scary numbers on maneuver nodes than.

[Ace in Space]

4 minutes ago, klgraham1013 said:

It's a good thing they didn't put those scary numbers on maneuver nodes than.

Yeah, that kinda bugs me. Stock displays how much delta-V we need, but not how much delta-V we have. That strikes me as rather silly. It's like if an RPG showed you how much damage you were taking but didn't display how much health you had.

[HvP]

Let's not forget the new batch of console players for which it is impossible to just install mods for this information.

[HebaruSan]

3 minutes ago, eightiesboi said:

First, speaking of modders that keep the community going, thank you.

My pleasure.

3 minutes ago, eightiesboi said:

I know I only had over-engineer and trial-and-error where you quoted, but I include equations further down. Your method is a combination of roughly doing the math and over-engineering, coupled with long experience

The only math is multiplication by 30 and then by 2 or 3, and you know your total delta V to within ~15%. I plead innocent to the charge of over-engineering or relying on complicated equations.

3 minutes ago, eightiesboi said:

(and you imply that you still make use of KER).

I used it in the past, but I've been using the above method on pure stock with good results.

3 minutes ago, eightiesboi said:

Of course, I don't have the sales numbers and demographics for customers of KSP, but I doubt that many gamers purchase it with the idea that they will get to roughly estimate rocket equations. Again, I am not saying it *can't* be done, but I am saying that Squad relying on modders to fill this hole in particular is a poor practice.

My point was that the nature of the rocket equation makes it possible to develop rules of thumb that exploit the similarities of different rocket stages, and to share one particular method for doing so in the hope that others will find it useful. If forum responders were able to give simple rules of thumb (like "multiply mass by 30 for the engine, then double it with fuel") instead of recommending mods, maybe some of the angst over a missing delta V indicator would be alleviated.

Just now, HvP said:

Let's not forget the new batch of console players for which it is impossible to just install mods for this information.

But they can also multiply by 30 and then 2 or 3.

[eightiesboi]

13 minutes ago, Starman4308 said:

I think part of the issue is that sometimes, strange staging arrangements can throw delta-V calculators for a fit. For a mod, that's no problem: Sarbian and Cybutek* try, but if you come up with something strange like a probe that uses ion engines to get around the Jool system with chemical engines used for landing, you may be able to break the delta-V calculator. If you're a modder, no sweat, you just tell the person "I'm sorry, I'm not going to handle your egregiously complicated case; go break out a calculator". For Squad, if they put a feature in, they have to support it.

*Is it Cybutek? I know Sarbian manages MechJeb, but I'm not up-to-date on KER.

There's also the element that Harvester's original vision was for a trial-and-error style. I disagree with that notion, but I'm not the lead programmer for KSP.

First, thank you--I restored the credit to Cybutek that inadvertently got deleted from my OP.

I agree with you in part as to Squad needing to support this feature--they would need to make certain it worked only in stock and unmodded KSP. While it would be nice if it worked on modded versions, Squad has no responsibility to make certain that whatever you add in can't break the game, just as modders have no responsibility to make certain their mods play nice with other mods (but yes, it is nice when they do). 

[StrandedonEarth]

Harvester's initial vision was for trial-and-error, and that was fine before there were any muns, and even after. But when other planets were added, T&E became too time-consuming. I'd be fine if a stock dV calculator could raise a flag saying something to the effect of "Ok, this build seems confusing/odd, I think you have this much dV, but YMMV."

IMO, mods-that-should-be-stock (KER, KAC, TWP) could/should be tied in to the tech tree and/or building upgrades, so as to not confuse or overwhelm new players.

Edited March 11, 2018 by StrandedonEarth

[MR L A]

Yeah, I'm currently playing without KER and honestly it feels horrible not knowing exactly what my new craft designs are capable of... very much stumbling about in the dark BUT I can totally see why they weren't added in the base game. If I came new to KSP and saw all those numbers straight away I'd have felt overwhelmed. Big enough learning curve as it is. BUT then again, it would be nice if KER was unlocked in the tech tree or was under "advanced tweakables".

[Rocket In My Pocket]

50 minutes ago, klgraham1013 said:

It's a good thing they didn't put those scary numbers on maneuver nodes than.

Well yeah that's fine, it's just one very simple number in m/s.

Really getting into the nitty gritty of a rockets Dv in atmo vs. out of atmo and for each stage and such is a lot of information for a new player. Then you have to add in learning about ISP and TWR. It really does have the potential to scare off casual gamers.

I'm all for having more advanced numbers and details available, perhaps hidden behind a menu toggle, but something friendlier and more inviting like a nice colored bar that fills up would be less "intimidating."

[qzgy]

4 minutes ago, Rocket In My Pocket said:

but something friendlier and more inviting like a nice colored bar that fills up would be less "intimidating."

So.... different colored bars for different stages filling up to a grand total or something?

[Kaskel2000]

I’m just getting into the Mac version of this game, after buying the PS4 version a week ago and becoming insanely addicted, then going on holiday abroad and taking the chance on an old 1.0 demo to see if my Mac could cope with it then buying the full game for it. But the whole trial and error thing is part of the fun for me. On the PS4 version I’d only just managed to go into mun orbit a few times and return.  With 1.4 on the Mac I e been slowly experimenting with my rockets and stages to where I’m close to a mun landing. That exploring of what my craft will do has been amazing fun. To the stage I said good night to my friends last night at 10.30pm and was still experimenting at 1am!

For experiences players I get how having dv visable would be a great advantage especially when trying to go to other planets but to begin with trial and error make for great gameplay. 

And yeah I’ve thrown £80 at this game the last week!

[linuxgurugamer]

25 minutes ago, Rocket In My Pocket said:

something friendlier and more inviting like a nice colored bar that fills up would be less "intimidating

But what would that colored bar indicate?  

This opens a can of worms.  Personally, I think that a basic list of dV per stage shouild be all that a minimal display should have, along with buttons which w would bring up info screens explaining what it is and what is needed to get to orbit.

Accept the fact that in order to d o well, you need to use numbers, and move on from there.

[genbrien]

delta-V + T2W ratio are a must IMO

[dlrk]

The fact that Squad has refused to implement the functionality of some pretty critical mods, like a Delta-V read out, or atmospheric/rotation-sensitive trajectory display, or realistic aerodynamics, or procedural parts is pretty mind-boggling.

[Foxster]

If a couple of numbers are too scary for newb players (as if!) then just add the ability to display them a little further down the tech tree or when one of the buildings has been upgraded. 

 

 

[Gargamel]

2 hours ago, Ace in Space said:

Yeah, that kinda bugs me. Stock displays how much delta-V we need, but not how much delta-V we have. That strikes me as rather silly. It's like if an RPG showed you how much damage you were taking but didn't display how much health you had.

This is my only argument for including DV readouts in the stock game. 

@HebaruSan Thank you for that bit of info, I will have to give that a go. 

21 minutes ago, dlrk said:

atmospheric/rotation-sensitive trajectory display, or realistic aerodynamics, or procedural parts is pretty mind-boggling.

None of those are critical mods.  I play all the time without. 

I can think of only one mod that really should be stock, no questions asked.  That's KAC.  There is no way to emulate it's functionality with out of the game tools.  DV you can use a calculator.  Precision landing can be done with math.   Etc, But there is no way to sync an outside alarm clock to the games warp system. 

[Cunjo Carl]

1 hour ago, linuxgurugamer said:

But what would that colored bar indicate?

There's one interesting option besides just deltaV, and that's your rocket's efficiency. It combines the effects of drymass and Isp to make a single value for how effective the mass in your rocket is. The good side is that it stays constant regardless of rocket size, and can provide a single-number rubric for how your rocket's doing. The bad side is, like Isp, it's not directly usable as a value without math, so it would only be useful as a bar. DeltaV's probably the better choice, but I figured I'd bring up the other option!

[klgraham1013]

2 hours ago, Rocket In My Pocket said:

Really getting into the nitty gritty of a rockets Dv in atmo vs. out of atmo and for each stage and such is a lot of information for a new player. Then you have to add in learning about ISP and TWR. It really does have the potential to scare off casual gamers.

You know.  I never really thought this was a game for casual players.  That's me though.

[magnemoe]

52 minutes ago, linuxgurugamer said:

But what would that colored bar indicate?  

This opens a can of worms.  Personally, I think that a basic list of dV per stage shouild be all that a minimal display should have, along with buttons which w would bring up info screens explaining what it is and what is needed to get to orbit.

Accept the fact that in order to d o well, you need to use numbers, and move on from there.

DV requirements are shown on nodes and you quickly learn how much is needed for various takeoff and landings. You also learn about margins, 
With no dV indications its all about guessing and overbuilding. Perhaps tie it with higher level pilots and probes, perhaps other kerbal professions too. say an level 2 pilot or 3 scientist and engineer, also an say level 2 of R&D facility to show it then building, mechjeb does an nice job unlocking stuff as you level up.