Why should i use spaceplanes?

[panzer1b]

If you don't enjoy doing so, then don't do go to Jool. Or fly spaceplanes

But but but.....over 75% of everything i send to jool is single stage! And i dont really do the whole refueling either, much less work to make a ship that has 7000dV in LKO then spend the time to launch a refueler

[Jouni]

There's an assumption there that something that happens later on in the player's game is going to be more fun than what is happening to the player right now. If that's the case, then you're right that players should always look for the absolute fastest way to get stuff into orbit, assemble big bases, fire off big rockets and... er... well... do... stuff...

Remember that we're talking about efficiency in this branch of the discussion. It has nothing to do with fun or player goals.

The only meaningful costs are opportunity costs: what you have to give up in order to achieve something. Any meaningful efficiency measure must therefore compare what you achieved to what you gave up in order to achieve it.

Funds are effectively an unlimited resource in the stock game. You can always grind more funds, until you have enough to do whatever you were planning to do. Because funds are unlimited, you don't really lose anything when you spend them. As a result, funds/tonne of payload to LKO is not a meaningful efficiency measure. There are no real gameplay reasons for choosing it over parts/tonne or decouplers/tonne.

Funds only gain meaning, if you consider the amount of time you spent in acquiring them. The real non-arbitrary efficiency measure is therefore hours of player time/tonne (or, more generally, hours/achievement). If you optimize for that, you get completely different results than from optimizing funds/tonne.

There are mechanisms that could make funds relevant as such. Maybe your space program loses funds and reputation over (ingame) time, and you can compensate it only by completing more and more ambitious missions. If either of them gets low enough, you lose the game. To further discourage grinding, vehicle construction/refurbishment and launch preparations could take time and reserve the relevant buildings. Every time you choose to fly a mission, you permanently lose something. You can trade reputation for funds by choosing to fly simple well-paying missions, and funds for reputation by completing ambitious missions, but every mission brings you closer to the end.

[Warzouz]

... Now SSTO tail lander rockets or fully recoverable SSTO rockets are cheaper still.

...

No they aren't. Space planes are cheapest, then rocket SSTO (recoverable), then staged rockets.

[GoSlash27]

Jouni,

I disagree with this reasoning.

"Funds" are indeed unlimited by your definition in KSP career, but by the same token they're equally "unlimited" IRL. We are all millionaires in that sense, it's just a matter of time and effort to get those funds into our bank accounts.

This does *not* mean that financial constraints are irrelevant to our lives, nor are they immaterial to our fictional space programs. You cannot launch what you cannot afford to build and you have to "grind" to earn money just like real life.

Therefore it *does* matter. The more efficiently you handle the money you have, the less time you have to waste grinding for funds.

and ultimately eddiew has a point I'm inclined to agree with; spaceflight is spaceflight no matter where you're doing it. Docking a spaceplane in LKO is the same thing as a precision landing on Moho AFA gameplay is concerned. What matters is achieving the goals you wish to achieve instead of grinding contracts for cash.

Of course all this goes out the window if you're playing sandbox.

Best,

-Slashy

- - - Updated - - -

No they aren't. Space planes are cheapest, then rocket SSTO (recoverable), then staged rockets.

^ Also this.

[eddiew]

Remember that we're talking about efficiency in this branch of the discussion. It has nothing to do with fun or player goals.

The only meaningful costs are opportunity costs: what you have to give up in order to achieve something. Any meaningful efficiency measure must therefore compare what you achieved to what you gave up in order to...

I was more arguing the concept of player time as a cost.

I see it as a goal, to fill my time with the bits of ksp that I find most fun. When building a ship, I enjoy the process, and achieve enjoying the process, so time usage was the aim, not the cost Time as cost is only true for a player not having fun and looking to get through what they perceive as a grind.

[GoSlash27]

^ I gotta go along with this. Whatever the objective is, I'm pretty sure it's not "spend as little time as possible playing KSP".

Best,

-Slashy

[panzer1b]

Whatever the objective is, I'm pretty sure it's not "spend as little time as possible playing KSP".

So true

[Norcalplanner]

^ I gotta go along with this. Whatever the objective is, I'm pretty sure it's not "spend as little time as possible playing KSP".

Best,

-Slashy

I think if the sentiment is modified slightly to "maximize the time doing what you find fun in KSP, and minimize the time doing what you find tedious in KSP" then it makes more sense. Speaking solely for myself, I can spend hours in the VAB working on a design, launching, reverting, tweaking, launching again, etc. with no real goal other than to refine my design for whatever metric I'm using at the moment, be it cost, capability, or part count. That's one of the reasons I do some of these crazy challenges that seem not to have any immediate application.

Getting back to the original question, use spaceplanes if you enjoy spaceplanes. Use something else if you don't. But I guarantee you'll learn even more about aerodynamics and spacecraft design even if you just do a little bit with spaceplanes.

[Warzouz]

^ I gotta go along with this. Whatever the objective is, I'm pretty sure it's not "spend as little time as possible playing KSP".

Best,

-Slashy

I prefer turning that the other way : "our time is so limited that we want to focus on what we like to do."

[nekogod]

The only things you should do in any game are things you find fun and rewarding, though this is especially true of sandbox games.

If you're playing career then a well piloted and returned spaceplane will almost always be cheaper than a rocket, otherwise there is no real reason to use them over a rocket unless you enjoy them.

[The_Rocketeer]

Well this thread has taken a leap since I last looked at it! Here's my 2 cents (never could resist...):

The only things you should do in any game are things you find fun and rewarding, though this is especially true of sandbox games.

I prefer turning that the other way : "our time is so limited that we want to focus on what we like to do."

Somewhat true - many games have less-fun parts that serve as structure for the more-fun parts - and yes, true. But what one person finds enjoyable may not be the same as another person. There's no reason to assume that one person working with rockets is having more fun than someone else working with spaceplanes just because they're *usually* quicker to build, take less testing and are faster to orbit.

I see it as a goal, to fill my time with the bits of ksp that I find most fun. When building a ship, I enjoy the process, and achieve enjoying the process, so time usage was the aim, not the cost Time as cost is only true for a player not having fun and looking to get through what they perceive as a grind.

There's an assumption there that something that happens later on in the player's game is going to be more fun than what is happening to the player right now. If that's the case, then you're right that players should always look for the absolute fastest way to get stuff into orbit, assemble big bases, fire off big rockets and... er... well... do... stuff...

...

Player time is only a cost measure if you perceive that you're "getting through" the grind of design, build and launch phases to get to the better thing later. An alternative view is that the goal of playing is to fill as much of my hour as possible with the activities I most enjoy. I have no need and actively don't want to minimise the time taken to design and launch something, if I'm enjoying the design and launch process

This is another difference. Some people find the act of assembling infrastructure and missions in orbit tedious while others actually enjoy it.

If you're in the former group then you have no use for spaceplanes. If you're in the latter, then they're indispensable.

You guys nailed it. This is exactly what I was talking about when I said...

...it comes down to whether you're enjoying engineering for a reward, or simply getting rewarded. I don't mind spending hours engineering a complicated-but-cheap solution to a problem because I enjoy the engineering process and the sense of accomplishment. If, as I'm sure others do, I was just trying to progress the game in as short as space of time as possible, then rockets are definitely (though not always) a shortcut to that.

...and very right-headed we are too.

It depends on how you define efficiency. I'd say that doing multiple launches is less efficient, because it takes more time. Player time is the fundamental cost measure in KSP, as all other measures can be derived from it.

If we ignore time and efficiency, designing a large modular ship can be quite hard. Interplanetary ships with a low TWR can live with a lot of wobble, but Eve landers have to be solid. The other option is to launch the ship empty and then fill the tanks with smaller tankers, but that can get quite tedious. (I once built a giant interplanetary ship in the 6.4x Kerbol System and then launched over 30 tankers to fill it. I'll never do anything even remotely similar again.)

Time *can* be considered a cost in the same sense that entertainment and enjoyment can be considered profits, but as you've sort of observed yourself, the profit per cost per game experience is not equal for all players. Therefore we can know the *value* of the cost (in hours), but not it's worth (except as a qualitative subjective).

Difficulty and complexity of a project can certainly put off many players from building towards a long-term goal, but that doesn't necessarily mean that the cost is definitively excessive in all cases, or that the time invested by any player is wasted, or that they should have just build a big-ass rocket instead of flying painstakingly to orbit 15 times. It's sad that you felt your big interplanetary mission was a waste of effort, because the only thing that actually makes that true is the fact that you think it is. If you instead felt achievement and success and ultimate satisfaction with meeting your goals, that would turn the entire calculation on its head.

[John FX]

As far as cash goes, in my career game I have over 140 million funds in the bank so I don`t need to worry about funds efficiency.

In RL I am time limited so the less time I spend designing and launching, the more I attain my desired in game goals. As I like designing the major point I wish to reduce timewise is launching.

Also I`ve launched *so* many things that launching is no longer novel and I just want the payload in space.

These are the reasons I prefer rockets.

That said, one HUGE reason to use spaceplanes is that almost every update for the last year or more has been dedicated to spaceplanes. I totally get why someone would think that they are playing the Kerbal Spaceplane Program and think that they should be making spaceplanes/ssto planes.

To be honest I`m getting tired of it...

After the U5 conversion update could we maybe have something other than spaceplanes as the focus for an update please?

[Jouni]

"Funds" are indeed unlimited by your definition in KSP career, but by the same token they're equally "unlimited" IRL. We are all millionaires in that sense, it's just a matter of time and effort to get those funds into our bank accounts.

Real-life money is just bits in computer memory, not really that different from funds in KSP. It's worthless in itself. Money only gets value from what people are willing to give up in order to gain it.

When we're measuring efficiency, we're comparing our gains to what we've given up for it. Because funds are just bits, measuring vehicle costs in them is equally arbitrary as measuring the costs in the number of vowels in kerbals' names. In order to get a non-arbitrary efficiency measure, we have to measure costs in something we sacrifice to achieve mission goals. Player time is the obvious choice in the stock game, while lost opportunities could be another in a modded game. Depending on the game mechanics, it might even be possible to compare these sacrifices in ingame units.

If we're content with subjective (but still non-arbitrary) efficiency measures, we could use player time spent for something unpleasant as the cost. The drawback of this approach is that subjective efficiency is subjective. Spaceplanes could be more efficient or less efficient than disposable rockets, depending on player preferences. Measuring costs in funds or other ingame units would become even less meaningful.

If we really need an objective non-arbitrary efficiency measure, I see no alternatives to using player time as the cost, redardless of whether the time was spent on something the player loves or hates.

[The_Rocketeer]

Real-life money is just bits in computer memory, not really that different from funds in KSP. It's worthless in itself. Money only gets value from what people are willing to give up in order to gain it.

When we're measuring efficiency, we're comparing our gains to what we've given up for it. Because funds are just bits, measuring vehicle costs in them is equally arbitrary as measuring the costs in the number of vowels in kerbals' names. In order to get a non-arbitrary efficiency measure, we have to measure costs in something we sacrifice to achieve mission goals. Player time is the obvious choice in the stock game, while lost opportunities could be another in a modded game. Depending on the game mechanics, it might even be possible to compare these sacrifices in ingame units.

If we're content with subjective (but still non-arbitrary) efficiency measures, we could use player time spent for something unpleasant as the cost. The drawback of this approach is that subjective efficiency is subjective. Spaceplanes could be more efficient or less efficient than disposable rockets, depending on player preferences. Measuring costs in funds or other ingame units would become even less meaningful.

If we really need an objective non-arbitrary efficiency measure, I see no alternatives to using player time as the cost, redardless of whether the time was spent on something the player loves or hates.

It seems to me there are two kinds of efficiency in discussion:

1. The efficiency of the activity of playing KSP, with costs in time played and profits in enjoyment of the experience.

2. The efficiency of the in-game economy, with costs and profits both in in-game currencies, with profits including the balance of achievement of mission goals.

Those who have repeatedly said that Spaceplanes are more efficient than Rockets are almost certainly speaking of 2.

@Jouni, until your last post I would have assumed, and have answered, as though you were speaking of 1. However, it seems to me now that you are using some sort of hybrid definition with elements of both:

3. Efficiency of activity of playing KSP, with costs in time and profits in in-game rewards including balance of achieved mission goals.

I can understand if your 'enjoyment' is directly linked to 'achievement of game goals' or 'beating the in-game economy', but that is not a suitable or comparable metric for all players of KSP, for the simple reason that not every player needs to succeed at the game to enjoy the experience of playing it. I can spend several hours working on a project that ultimately fails, but I will still have enjoyed the time spent working on it.

Perhaps this is the fundamental difference between those of us who esteem and enjoy spaceplanes and those that don't.

To put it simply, efficiency is not simply a measure of unitised cost, it is the comparison of that cost against a gain or profit. If you can't unitise the gain, you can't compare the efficiency of one situation with another, and therefore you can't compare the enjoyment of one player building, developing, testing, and eventually utilising a spaceplane with another player doing the same with a rocket. There is no suitable single metric that would accurately reflect the profit of the experience of both players.

Edited September 23, 2015 by The_Rocketeer

[GoSlash27]

Real-life money is just bits in computer memory, not really that different from funds in KSP. It's worthless in itself. Money only gets value from what people are willing to give up in order to gain it.

When we're measuring efficiency, we're comparing our gains to what we've given up for it. Because funds are just bits, measuring vehicle costs in them is equally arbitrary as measuring the costs in the number of vowels in kerbals' names.

Jouni,

As I said, this is true in the abstract, but as a *practical* matter neither of us actually operate that way IRL or in- game. It's all well and good to postulate that "money is just bits in a computer", but the guy at the gas station ain't tryin' to hear that when you need to fill up your car. You don't get gas unless he gets paid.

Our ability to do what we wish is limited by how much money we have. We can spend less time earning money and more time accomplishing our personal goals by operating more cost- effectively.

Therefore cost- effectiveness is a perfectly valid measure of efficiency.

Now that we've both restated our position on the matter, I'm confident that we're not going to wind up in agreement about this. Rather than belaboring it, I'll happily bow out on this subject.

Best,

-Slashy

[Van Disaster]

No they aren't. Space planes are cheapest, then rocket SSTO (recoverable), then staged rockets.

To clarify a bit - the upfront cost of a recoverable SSTO rocket is way less than a spaceplane for the same payload, but the unrecoverable percentage ( fuel ) is massively higher to compensate. So the rocket is cheaper to buy, and the spaceplane to run...

I've stuck 250+ tonnes in orbit in a spaceplane, I'd probably not actually launch anything bigger than that on a rocket either, I tend to just launch awkward things with them. Most stuff I'll print in orbit with the EL mod anyway...

[Jouni]

It seems to me there are two kinds of efficiency in discussion:

1. The efficiency of the activity of playing KSP, with costs in time played and profits in enjoyment of the experience.

2. The efficiency of the in-game economy, with costs and profits both in in-game currencies, with profits including the balance of achievement of mission goals.

My point is that 2 is not supported by the actual stock gameplay. It's just an arbitrary goal a player can choose. If you look just at the game mechanics, the following outcomes are equivalent:

1. Mission costs 100000, revenues 110000, recovery bonus 90000.
   
2. Mission costs 100000, revenues 200000, recovery bonus 0.
   
3. (Mission costs 100000, revenues 110000, recovery bonus 0) x10.
   

To distinguish between them, you have to take offgame considerations into account.

I can understand if your 'enjoyment' is directly linked to 'achievement of game goals' or 'beating the in-game economy', but that is not a suitable or comparable metric for all players of KSP, for the simple reason that not every player needs to succeed at the game to enjoy the experience of playing it. I can spend several hours working on a project that ultimately fails, but I will still have enjoyed the time spent working on it.

Remember that we're talking about efficiency, and in particular which efficiency measures are supported by the actual gameplay. Enjoying the game has nothing to do with it.

To put it simply, efficiency is not simply a measure of unitised cost, it is the comparison of that cost against a gain or profit. If you can't unitise the gain, you can't compare the efficiency of one situation with another, and therefore you can't compare the enjoyment of one player building, developing, testing, and eventually utilising a spaceplane with another player doing the same with a rocket. There is no suitable single metric that would accurately reflect the profit of the experience of both players.

I thought we were talking about the efficiency of achieving well-defined goals. To this end, I classified the efficiency measures into three categories:

• Arbitrary: Funds / tonne of payload to LKO; vowels in kerbal names / tonne of payload to LKO.
  
• Subjective non-arbitrary: Time used for unenjoyable tasks / tonne of payload to LKO.
  
• Objective non-arbitrary: Time used / tonne of payload to LKO.
  

As I said, this is true in the abstract, but as a *practical* matter neither of us actually operate that way IRL or in- game. It's all well and good to postulate that "money is just bits in a computer", but the guy at the gas station ain't tryin' to hear that when you need to fill up your car. You don't get gas unless he gets paid.

I was talking in practical terms. For example, I could take a job that pays better than my current job but is less interesting than it. I could save money by living in a smaller apartment, or by not spending it for travelling around the world or for buying expensive computers. In all of these cases, I would have gained more money by giving up something that I enjoy. I have not done so, because I feel that the opportunities I lose because I don't have that money are worth less than the enjoyment I lose by having the money.

Money is just numbers. It's value comes from individuals' subjective valuations of it. Markets give money its objective value by aggregating individuals' current valuations. The temporary objective value of money determines how the subjective value of the lost opportunities compares to the subjective value of the lost enjoyment at that moment.

[The_Rocketeer]

Remember that we're talking about efficiency, and in particular which efficiency measures are supported by the actual gameplay. Enjoying the game has nothing to do with it.

I'm sorry, but here we've come to an impass. The primary purpose of playing KSP at any time, for any non-developer player, is for entertainment. Any other goal is totally arbitrary, unitised or not. If you are measuring the cost in time spent at the computer, the only relevant profit is your enjoyment of that time - why else would you be there? If meeting in-game objectives wasn't enjoyable, you'd find something else to do, like not meet them. It's the extent to which you enjoy the time you spend that defines the worth of that time, and nothing else at all.

From my perspective, this is fundamental. Any debate about cost-efficiency that doesn't acknowledge the primary purpose/product of that cost is a statistical curiosity at best, and as someone who cares little for statistics that's just smoke on the breeze to me.

Edit: Let's try to keep in mind the KSP is a game, and it's worth is totally subject to the player's tastes, playstyle, and available alternatives. The sort of comparison you're trying to draw is hopelessly irrelevant to the topic of this thread, since it neither gives a reason to build spaceplanes nor in anyway proves that players categorically shouldn't use spaceplanes.

Edited September 23, 2015 by The_Rocketeer

[Hodo]

To clarify a bit - the upfront cost of a recoverable SSTO rocket is way less than a spaceplane for the same payload, but the unrecoverable percentage ( fuel ) is massively higher to compensate. So the rocket is cheaper to buy, and the spaceplane to run...

I've stuck 250+ tonnes in orbit in a spaceplane, I'd probably not actually launch anything bigger than that on a rocket either, I tend to just launch awkward things with them. Most stuff I'll print in orbit with the EL mod anyway...

This is exactly what I am saying.

I have had some stupid expensive upfront cost SSTO spaceplanes. One of which comes to mind my SP-406 and later line.

Those craft had a start up cost around 600-750k to launch, and an operating expense of 10-20k per launch.

[Jouni]

Edit: Let's try to keep in mind the KSP is a game, and it's worth is totally subject to the player's tastes, playstyle, and available alternatives.

"Game" can mean many things, depending on the context. It could be a product, an abstract mechanism, or a subjective experience. When we're talking about the details of game mechanics, the game is an abstract mechanism, because the discussion wouldn't make sense in other contexts.

The sort of comparison you're trying to draw is hopelessly irrelevant to the topic of this thread, since it neither gives a reason to build spaceplanes nor in anyway proves that players categorically shouldn't use spaceplanes.

You're contradicting yourself here. First you claim that what I'm saying is irrelevant to the discussion. They you justify it by claiming that it's actually relevant to the discussion, because game mechanics don't give the player any reasons for using/not using spaceplanes. Remember that some people have claimed otherwise, as they've stated that there are efficiency or cost reasons for using spaceplanes.

Some people are more interested in discussing game mechanics, as they're objective facts shared by all players. Others are more interested in subjective opinions. Both kinds of discussion are generally on-topic when talking about games.

[The_Rocketeer]

"Game" can mean many things, depending on the context. It could be a product, an abstract mechanism, or a subjective experience. When we're talking about the details of game mechanics, the game is an abstract mechanism, because the discussion wouldn't make sense in other contexts.

You're contradicting yourself here. First you claim that what I'm saying is irrelevant to the discussion. They you justify it by claiming that it's actually relevant to the discussion, because game mechanics don't give the player any reasons for using/not using spaceplanes. Remember that some people have claimed otherwise, as they've stated that there are efficiency or cost reasons for using spaceplanes.

Firstly, yes I am aware that 'game' has many meanings. If you had a point here, it's lost on me. I don't think we're in any doubt that KSP is the game in question. This is after all the forum that pertains to that particular game.

Secondly, I'm not sure you understand the meaning of the word 'contradiction'. You quoted me not contradicting myself, then explained that I did contradict myself by saying something non-contradictory.

There are in-game efficiency and cost reasons for using spaceplanes - it requires less kerbuck capital to use a spaceplane for equivalent payload than any kind of vertical-launch rocket. There are also 'game-enjoyment/time' efficiency reasons for using spaceplanes, if you find them in any way enjoyable, and absolutely if you find them more enjoyable than rockets.

I'm afraid that simply insisting that you're right and I'm wrong doesn't actually advance your argument. I've explained why I believe you're chasing wild geese with your comparison metrics since they're not relevant, and I've explained why they're not relevant.

I think it would be for the best if I also bow out of this conversation, since I'm finding your reasoning questionable and I wouldn't want to be overtly rude.

[Jouni]

Firstly, yes I am aware that 'game' has many meanings. If you had a point here, it's lost on me. I don't think we're in any doubt that KSP is the game in question. This is after all the forum that pertains to that particular game.

Some forum threads discuss game mechanics without taking player experience into account. Other threads discuss player experience without taking game mechanics into account. Some threads discuss both. It seems that there are KSP players who think that all three are valid approaches to discussing a game.

There are in-game efficiency and cost reasons for using spaceplanes - it requires less kerbuck capital to use a spaceplane for equivalent payload than any kind of vertical-launch rocket. There are also 'game-enjoyment/time' efficiency reasons for using spaceplanes, if you find them in any way enjoyable, and absolutely if you find them more enjoyable than rockets.

As I've pointed out, those are not ingame reasons. The game doesn't care whether you made that 100000 by flying one mission or ten missions. As long as you're making profit, you can keep trying whatever you want without losing any opportunities. It's up to personal preferences, whether higher profit margins or higher returns on investment matter.

Compare this to most tycoon games, where you're competing against one or more opponents. If you're not fast enough, profitable enough, or aggressive enough, a competitor may achieve something before you, and you miss that opportunity permanently. In those games, efficiency matters. In KSP, it doesn't.

[Goomblah]

Efficiency and the speed of gameplay in KSP are intentionally irrelevant. Despite the sense of progression that Career and Science modes provide, KSP is first and foremost a sandbox game. Within your Career file, you are given a ton of wiggle room to take different approaches to running your space program; you really aren't forced to take a specific path towards your goals, whatever they might be. You very well could make that 100k by doing ten missions, or do it all in one; it's the player's choice. Player choice is what actually gives things in KSP value - funds, resources, and even Kerbals' lives are meaningless unless the player gives them value. In general, someone playing a game is putting in their time and expecting to get entertainment out. Time vs entertainment is really the core element of all value in KSP; funds have value because they represent time spent (grinding for funds) and can be used to produce entertainment (fun missions). If you can get funds in an enjoyable way, they lose value because you have to spend less time doing not-fun stuff to get them. If each of those ten missions is suitably entertaining, or each goes ten times as fast as the one big one (including development costs), then it's worthwhile to do all ten instead. But, in general, doing things at larger profit margins for bigger rewards produces more funds for a given time investment, and are often rewarding and entertaining as well - big missions are cool. Efficiency matters only to the extent that it remains more time effective than less efficient methods, taking into consideration that funds and infrastructure (like mining colonies) cost time as well.

Now, exactly what activities are "fun" versus "not fun" in KSP is extremely subjective, and different players' approaches to the same problem will vary widely. Some people (myself included) enjoy the engineering and design elements of building an SSTO. Efficiency may be less of a requirement (as in, the space program will fail without it) and more of a goal to strive for. That's why there are a number of challenges featuring SSTOs; some people just enjoy making the most efficient/simple/small/easy to use spacecraft they can, regardless of how practical or necessary they are for career mode. There doesn't need to be an in-game justification for everything players do; what matters are out-of-game factors, such as time use and enjoyment of the game. It's up to each player to decide how they want to tackle each mission, and how they want to devote their in-game and out-of-game resources towards finding a solution.

[The_Rocketeer]

@Goomblah, you talk sense.

[eddiew]

...There doesn't need to be an in-game justification for everything players do; what matters are out-of-game factors, such as time use and enjoyment of the game. It's up to each player to decide how they want to tackle each mission...

Well put

The only valid answer for 'why' you take any particular route in KSP is 'because you want to'. In 0.90, I had a nuclear-free career. Why? Because I wanted to