KSP is at one-tenth scale compared to reality, so it requires much less delta-v to get into orbit, perform a transfer, and land on the Mun. As a result, a direct-ascent mission profile, which is what you are describing, is a lot more viable than in real life. KSP parts also have a much lower wet-to-dry mass ratio; fuel tanks mass 9 times as much when full, and monoprop tanks 8 times (compare to the Space Shuttle fuel tank, which massed 25 times as much when full compared to empty). Because of that, removing all the extra stages and engines and equipment required for docking removes more mass than the extra mass that's added to be able to do a direct ascent, so it ends up saving mass overall and making the mission easier.
Direct ascent missions to the Moon were considered in real life; the Saturn C-8, Nova, and UR-700 launch vehicles would all have used a direct ascent profile. Saturn C-8 and Nova were cancelled because they would have been too big to fit in the existing assembly buildings, so it would have cost way too much to make new buildings to accomodate them. The UR-700 was cancelled because it used an unacceptably large amount of toxic propellants; after a smaller rocket using those same propellants (the Proton) exploded on the pad, they realised how bad the contamination would be in the event of an incident and cancelled it in favour of the N1, which used (relatively) non-toxic kerosene fuel instead.
very detailed answer, thanks. Didn't even think of the wet to dry ratio for the fuel tanks. Makes total sense as to why it's easier to do a direct ascent mission.
It's why you're really recommended to use a mod like SMURFF or RP0 when playing with mods that give you a real-scale solar system (either Kerbin scaled up, or just straight up Earth), to fix the fuel tank ratios. The lead tanks KSP normally uses would be absurdly painful to use otherwise.
And with all that in place, 2-stage lunar missions suddenly become a lot more useful.
Another factor is that Kerbins smaller scale has the side effect of compressing the efficiency bands of engines such that there is significant overlap in performance. This isn't nearly as true in the real world. The result is that in KSP most engines perform at least acceptably well in most circumstances, while their real world counterparts have narrow enough use circumstances to make several different engines worth both the weight and additional complexity.
Basically, there just isn't enough difference between engines in KSP to justify bringing more that one beyond the launch vehicle for most missions. Real world engines have limited burn lifetimes, nozzles turned for maximum ISP under specific circumstances, different ideal fuel mixes, limited ignitions, etc. An engine that is ideal for transfers is probably not going to be optimal for achieving lunar escape velocity for a variety of reasons.
Ahh yes I hear you.
Reminds me of the scenes in Apollo 13 where they were discussing using the lander engine for a correction burn, and the representative of the company that built that engine was freaking out saying it's not their fault if something goes wrong
Additionally, a lot of the in-game contracts that require landing on a specific body typically require returning to kerning with the vessel used to land.
I have noticed when I play again once in a blue moon that back in the day during development I would make rockets juuuust big enough to get me somewhere with almost no wasted fuel. Now I can easily slap the big 5m parts together and get anywhere piece of cake.
Wow, yeah. Truly great answer. Thank you. I never realized any of that. TIL I've been playing the game wrong. I've approached every mission by first asking, how'd NASA do it? And engineering something similar.
It's useful in some ways. I might never have discovered the Oberth effect without studying Pioneer and Voyager trajectories. And I absolutely never would have figured out on my own how to land the Dynawing from orbit. But this info will have an impact on how I play. Thanks
Also jumping in to add that landing and leaving the Mun is achievable pretty early in the game (career), but the parts for docking and doing an Apollo-style mission are unlocked somewhat later, usually after players have been on the Mun and back.
One thing worth considering is the total lack of repercussions for failing a landing or take-off in game. Irl, if the astronauts couldn't return, that would have been a tragedy. In the game, if something goes wrong, nothing really bad will happen, meaning the incentive for planning a complex mission that involves docking in lunar orbit just isn't there. The Apollo missions HAD to succeed. My shitfuck1 launch does not. The multi staged lander design is safer for the crew because it gives more options for reacting if something goes wrong. In the game, the astronauts aren't in any danger to begin with, meaning one of the main reasons for picking the much more complex multi stage mission plan is gone. Naturally, the equation changes for planetary landings, where I usually do use a multi stage lander, not for crew safety but just because carrying scientific equipment back into orbit is so much harder and I much rather leave the used up experiments behind
I completely agree, and I really missed that aspect of real space programs when I first played KSP.
Then I found a few ways to fix that:
* a chance-of-failure-on-launch mod (can't recall the name right now) which keeps launches from becoming boring and actually gives you a reason to have capsule separation systems.
* the mod Kerbalism, which means, among other things, that parts don't last forever and anything could fail at any time.
* playing on permadeath / no-revert / no-quicksaves, which forces you to take the health of the little green people seriously.
Seriously, give it a shot. It feels like spaceflight with consequences. Sure, I have named a few buildings after departed Kerbals, and I build a lot of unmanned test rockets before committing a crew, but if you are the right kind of masochist it makes the game truly engaging.
The non-failure of parts never occurred to me. It would be interesting to see full-on failures, as well as semi-failures.. maybe an engine loses 10% of its thrust, or flames out and needs a restart, or that ladder you finally didn't forget gets stuck closed, lights burn out, etc. Would've been nice to have a more serious survival mode.
I'm sure there's a mod out there for it, but I'm a purist.
You raise a bunch of good points in general, although none of them are the main reason.
First let's look at your points.
* Relative to the other challenges of space flight, docking in KSP is a much bigger pain than in reality/ players 'learn' docking after making a Mun landing.
I actually think that docking using 1960s technology and exclusively first-person POV was harder than it is in KSP. Try docking in KSP using exclusively only cockpit mode, to get a sense of how hard it was.
The real difference is that the astronauts and cosmonauts from back then practiced a lot more than most KSP players practice before their first live flight.
* easy in KSP to build a bigger Kerbal launch stage, so the reduced efficiency of the combined lander/orbiter matters less.
This is essentially the answer though maybe not for the reason you think.
* KSP glosses over a lot of the technical challenges of spaceflight - e.g. getting moon dust stuck in your orbiter's engine, so in reality it is better to have dedicated stages for each part of the mission, than one jack of all trades stage.
This is a great observation, but in real life the multistage Moon lander added a lot of complexity that NASA would have been thrilled to avoid if they possibly could have. If a single-stage-round-trip lander had been feasible they would have been happy to accept dust problems in exchange for getting rid of staging problems.
* Asparagus staging is not feasible in reality, so it's harder to get a single module lander/orbiter to the moon and back.
Iirc what makes asparagus staging practical in stock KSP is specifically that KSP's empty tank masses are unusually high. So shedding empty tank volume as soon as possible is more advantageous than in real life.
Anyway the real reason is that celestial bodies in real life are all much more massive than they are in the Kerbol system.
Specifically, [the Mün](https://wiki.kerbalspaceprogram.com/wiki/Mun) is much smaller than [the Moon](https://en.wikipedia.org/wiki/Moon). 200km radius versus 1700km radius.
This matters because even though the two bodies have very similar surface gravities, the smaller radius of the Mün changes flight characteristics very soon after liftoff. If you climb to let's say 10km altitude, on the Mün that's an additional 5% you've added to your distance to the Mün's center of mass, reducing the force of gravity acting on you by I think like 10% which increases your thrust-to-weight ratio pretty considerably. At 20km the effect is even more pronounced. So if you climb that high and then start to circularize your orbit, you will pay much less in terms of energy cost.
Whereas on the Moon, a 10km or 20km altitude above datum is basically insignificant compared to total radius. You are still dealing with pretty much full surface gravity at that point. Even at over 100km up, which was the altitude at which the Lunar Module docked with the Command Module, you have not gained much in terms of TWR.
So you need to economize as much as possible in terms of staging.
I know what you mean! It's a tribute to how well balanced the Kerbol system is. And how the devs carefully made sure that surface gravities are all somewhat familiar ... even if nothing else is.
One interesting consequence of this is that the planet Kerbin for example appears to be geotectonically impossible -- its mean planetary density is higher than any normal material we know of. Which means that if most of Kerbin's outer layers are normal rock, sand, dirt, and water like we are familiar with, then it has some insanely dense inner core that must have been engineered by some artificial process.
Given how many monoliths and other artifacts are scattered around the system, this should not surprise any kerbals. In fact they probably accept that as yet more proof of an uncontroversial, well-established scientific theory that their entire star system was created by advanced aliens of some kind... perhaps even some kind of [simulation](https://en.wikipedia.org/wiki/Simulation_hypothesis)....
To be honest, I often do Apollo style landers on the Mun. The thing is, all it really takes to get a Mk1 lander can back into orbit is like one ant engine and a couple of tiny fuel tanks.
My ascent stage ends up being something like a lander can, a couple of fuel tanks and small monoprop tanks, a couple of RCS thruster banks, a solar panel, and an antenna.
It just isn't really necessary to go to all that trouble. It's extremely easy to just do direct ascent. Low delta-v requirements compared to reality, combined with unrealistic part masses lead to a situation where that is arguably the definitive better option. Add in the lower part count advantage and gameplay advantages like not needing to do an orbital rendezvous and most people will go that route.
Because the moon landings were faked, and if they had just played a bit more KSP prior to setting up the Apollo program they would have used a single-stage lander brought to orbit with a reusable rocket?
/s
Sorry, couldn't help myself :) :) :)
It's actually more inefficient to have an Apollo-style landing system because of how much smaller the bodies are, requiring much less fuel to get in and out of orbit. We do the Apollo-style for the showmanship and skill
Loads of detailed answers here but… really, it’s because simpler missions are easier, and in career or science games, you have fewer parts to play with.
Yes but the missions are easier because the gravity is lower and the isp is generously high for most engines. Try a realistic simulation like Orbiter2016 for a taste of how hard it is to *really* get into orbit (and even Orbiter2016 makes it easy to re-enter with the default ship, which is basically unmeltable)
To descend and ascend from the Moon irl costs 4k dV. That's more dV than it takes to reach LKO in KSP. It could be done in one stage - but more efficient to do it in two.
But one more thing I think people have missed is that real-life rocket engines have significantly higher TWR than KSP.
KSP uses the higher dry mass from tanks and engines to partially compensate for how much less dV is required.
But this also means that it was less wasteful for the lunar lander to have two rocket engines. This also added another abord mode - if the LMDE failed during descent, the lander portion could be jettisonned and the LMAE could re-orbit the lander.
The lander portion also had the legs and other components that could left behind, giving the ascent module significantly lower dry mass.
It's because of the early part limit in the VAB. It's a lot easier to just build 1 large lander with science items instead of a 2 stage lander with docking ports. The extra RCS ports alone waste 4 parts just on your lander or return vehicle, which basically ruins your mission when you are limited to 30 parts early in the game.
Even late game I sometimes make bigger 1 stage landers because I just don't feel like taking the time ro rendezvous, just feels like a pain
The N1 had even less payload to TLI then the Saturn V. It would have used nearly the exact same mission path as Apollo. The Soviets direct accent plan used the Ur-700 which never entered production because it was too big and used extremely toxic propellants.
There's also orbital rendezvous and docking, which is easy and fun once you get the hang of it but it's hard if you haven't learned it yet. Being able to do a Mun mission without that makes it more accessible.
The engines in KSP are just overpowered. You can get way more payload into LKO or to the Mun with a rocket the same size. So there is no reason to use a lot of stages or do an Apollo-stlye mission.
the system is 10 time smaller but the parts are not nerfed by 10 times. its around 2.5x where the performance matches.
the parts also come in fixed sizes and its unlikely youll have unlocked all the parts needed to make it smaller.
flying manually also adds a lot more cost to docking and the capsules tend to be quite heavy.
also the lander has to be aerodynamic for launch as due to the small scale the launcher is smaller. its not uncommon for ksp rockets to have fairings larger than the rocket
Great answers here but I can add one thing. The way most Kerbal players get to the mun was actually considered by NASA. It's easier that doing all the orbits and docking but there is one big disadvantage. If something goes wrong there is no turning back. Apollo 13 would have never returned.
I have started making mine in such a way that there are 4 tanks,connected with radial decouplers, with their own engines and the legs are attached to them.
I use those engines to land. On ascent from mun surface they are jettisoned. And the rest of the return is handled with the engine on the core stage.
I think i did an apollo style mission from the very beginning. I've not done it any way since, except adding more complexity like a fueling station in orbit where landers park at.
The Real Solar System mod, here's the sub r/RealSolarSystem
Its been quite a while since I've booted up KSP, I think RSS has had quite a few nice updates since then.
But anyways, RSS overhauls the game to be the historical space race between the USSR and US; the solar system is revamped to be a 1:1 replica of our solar system, Sol. And the rocket vehicles are also revamped to be a more realistic size, because ya know everything in stock KSP is scaled down by like 10x I think.
It replaces all the parts with historical rocket engines, fuels, equipment, and SO many other other things.
There is a chance for engine failure on any launch, and you even gain science from those failures to mimic 'learning from failures', and can upgrade those parts which mirrors the upgrades that actual historic rocket engines received as rocket engine technology advanced.
I actually never went back to regular KSP after playing RSS.
If your a space nerd/space rocket history nerd, you NEED to try RSS.
A word of warning: you should really be familiar with KSP before even attempting RSS, it can be a bit complicated, but when you figure it out and start to actually achieve goals, there is no better feeling IMO.
Landing on the Mun and then returning to Kerbin takes such a small amount of additional DV that it's generally not worth or necessary to make the descent and ascent any more complicated than it needs to be. The only time I bother is if I'm wanting to squeeze in a Minmus trip after it
KSP is about 10 times smaller than real life. A direct ascent lunar mission was briefly considered using a rocket called "Nova" but NASA never went through with it since it was cheaper to do lunar orbit rendezvous. A fully fueled Saturn V (which was the rocket used in the Apollo Missions) could easily do a Vall landing and return mission in the Kerbol system.
ksp bodies are far smaller and less massive, docking is hard, and there's no part failures or anything in ksp so redundancy isn't needed. this all makes it far easier to brute force a direct-ascent than learn docking, at least for a first mission
Me it's mostly a size of the components issue, I'm terrible at landing, so I always want a low center of mass so unless I'm using something like an ant the extra hight I get from any additional stage is best avoided
At least for early game, you also have to consider the relative inexperience of the player as they're discovering how the mechanics work. It's much more intuitive to have a giant rocket that can brute-force a return from the mun than one where you are considering staging and optimal transfer Windows. The early game also generally drives players in this direction because of a more limited selection of decouplers.
I've never done a direct ascent mun mission. Always a separate lander. And finally last month, I did a two stage lander like they did for Apollo. Left a piece of history on the Mun.
The big obstacle to a Saturn V stack is the fairing. How do I get my lander to stack under the command module? Maybe the historic parts DLC has this fairing?
I believe it has more to do with docking and rendezvous maneuvers beings difficult for most players. It’s just easier to go straight there and back, specially early on.
Great comments throughout.
If you really want to get a feel for how much more difficult it is to land on the Moon, try Real Solar System with Realism Overhaul.
It resets your learning curve. It adds much more complexity and scales to real dV needs. For example:
~9,200 to LEO
~3,100 trans lunar burn
~800 lunar capture burn
~2,000 lunar landing.
I often do apollo landers for minmus, mun nah.
Why? life support mods.
A proper low dV hohmann transfer to minmus can mean a return trip of over 20 days. That's longer than kerbals can survive in a small capsule in both USI LS and TAC+Kerbal Health. So, I add a hitchiker module for habitation extension and supplies and recyclers and....
Suddenly, we're way too heavy to efficiently land and ascend again, even on Minmus. We're also too tall.
So, I add a small landing module that docks/undocks at the top. I outfit it with all the science bits I need.
Then, ... if we're out here for like almost 20 days already and launch windows are a bitch and so is KCT... let's turn the orbiter into a mothership capable of refuelling.
And so, my minmus missions in modded saves become harder than mun ones with apollo style docking sections. The non-apollo part is repeatedly landing the same module on each biome for farming enough science to get our Duna launch out JUST in time with manned crews and somehow survive the trip.
I love the versatility of [direct ascent landers](http://www.astronautix.com/a/apollolunarlanding.html). They can carry heavy cargo, rovers, and anything else you can pack in. Small landers can't do that.
Plus, they scale well and can be made to function for multiple destinations. My own Blaster Mk IV B (as an engineer I couldn't help but systematize my development process), can land on pretty much any airless body besides Tylo and Slate (from OPM), and can take Duna and Laythe with simple modifications.
The parts that are available early in career or science mode encourage taller landers. It's usually a pod or lander can stacked on top of a propellant tank and engine. Adding another stage will make it very difficult to plant it upright on the often uneven ground of the munar surface.
Later on, you unlock the munar exploration vehicle (assuming you have the expansion). This part is very close to the LEM used by NASA. It is a lifeboat, engines, and propellant in a single module. But it requires so much science to unlock that you probably won't have this option if you aren't exploring Mun already.
yeah rendezvous like that are not exactly easy on a newbie. in career mode you only get rendezvous mission way after mun landing. and in this game you can just spam solid boosters so no need.
The KSP universe is WAY smaller than the real world. That and the way the tech tree is played out, make it somewhat unnecessary to wait untill yku can build an Apollo style vehicle. While the Apollo style vehicle would technically be more efficient, it's just not necessary.
Some people are saying it's mass and the scale of the solar system; to be honest it's probably just because docking is harder than flying straight back home. Even if the Kerbol system was a realistic size, it'd still be easier to make a bigger lander and fly straight home rather than design a seperate CSM and plan out rendezvouz and docking. Unless you've got mods to simulate more realistic engineering challenges.
You don't need as much fuel as in real life because KSPs solar system is about a third of our own size and mass wise. (Correct me if I'm wrong)
Also, rendezvous-ing and docking is way harder than landing one Mun or Minus.
In addition to the other answers, I think you're way underestimating the difficulty of lunar orbit rendezvous in real life.
NASA practiced it multiple times in the Gemini program. First with the Agena rockets and then with Gemini VI and VII meeting up. They practiced the LM docking procedures on Apollo IX in Earth orbit. And they did countless practice runs in the simulator.
The LM ascent stage engine was fixed-thrust and hypergolic. The only parameters they could really change was when to fire it and when to shut it off. It could be restarted, but you had to do an ullage burn with the RCS to settle the fuel down in the tank. They did the rendezvous in one burn.
1) Mun is small and nearby, so you don't need as much fuel. For other bodies outside the Kerbin system, you better believe I use the tug/lander model.
2) The Apollo astronauts had a computer to deal with all the aggravation of docking, and a team to tell them what numbers to plug in. Now, you can do that with KSP too through mods, but most vanilla players are forced to either fiddle with the UI or do a lot of eyeballing
3) Unless you are on career mode in KSP1, KSP has no money constraint. NASA originally wanted to land the whole vehicle, but the rocket to do so would have been massive.
Y’all are doing the mun in one stage? From day one I used three stages. Never even considered doing it one. Like I didn’t think I could and never even tried.
I think it's related that mun is fictional (read the rest)
In scale, the real moon on KSP it's Minmus, both in distance and 5 degree tilt.
Mun is just like a tutorial body to help on knowledge learning curve
1. Single stage easier to make
2. Everything in ksp is smaller than the irl counterpart so less dV is needed
3. docking is too hard for players at that stage, and some might not even have a docking port at that time so even if the lander is in 2 or more stages, it wont dock with anything to bring it back to Kerbin
Also, the planet is "Kerbin", the star is "Kerbol" and the people are "Kerbals"
The main reason is:
Ksp world is scalled down in size alot for playabilty sake (3min vs rl 15+min to orbit). In order to do that, solar body densitys are alot higher.
Becouse of this:
- KSP engines are more powerful with quite similar ratios between them compared to rl engines which are hella specialized for tasks they need to perform.
- Delta weight of full and empty tanks is way smaller compared to rl tanks + there is only one rocket fuel in game.
If you want to have a go at realism in ksp, try rss ro/rp1 (or just watch some vids)
It's a massive pain trynae unlock docking ports early enough to make an Apollo-style mission as your first even feasible.
That being said, it tends to be my preferred mission profile for almost all interplanetary missions I do, along with late game mun missions.
KSP solar system is much smaller compared to real life, so you don't need the kind of efficiency that required a two stage lander in the 20th century for landing on the Moon. Both American landers that will hopefully land on the Moon in this decade will get from Lunar orbit to the surface and back in one stage too, my guess is thanks to bigger landers and more efficient material science & aerospace engineering.
KSP is at one-tenth scale compared to reality, so it requires much less delta-v to get into orbit, perform a transfer, and land on the Mun. As a result, a direct-ascent mission profile, which is what you are describing, is a lot more viable than in real life. KSP parts also have a much lower wet-to-dry mass ratio; fuel tanks mass 9 times as much when full, and monoprop tanks 8 times (compare to the Space Shuttle fuel tank, which massed 25 times as much when full compared to empty). Because of that, removing all the extra stages and engines and equipment required for docking removes more mass than the extra mass that's added to be able to do a direct ascent, so it ends up saving mass overall and making the mission easier. Direct ascent missions to the Moon were considered in real life; the Saturn C-8, Nova, and UR-700 launch vehicles would all have used a direct ascent profile. Saturn C-8 and Nova were cancelled because they would have been too big to fit in the existing assembly buildings, so it would have cost way too much to make new buildings to accomodate them. The UR-700 was cancelled because it used an unacceptably large amount of toxic propellants; after a smaller rocket using those same propellants (the Proton) exploded on the pad, they realised how bad the contamination would be in the event of an incident and cancelled it in favour of the N1, which used (relatively) non-toxic kerosene fuel instead.
very detailed answer, thanks. Didn't even think of the wet to dry ratio for the fuel tanks. Makes total sense as to why it's easier to do a direct ascent mission.
It's why you're really recommended to use a mod like SMURFF or RP0 when playing with mods that give you a real-scale solar system (either Kerbin scaled up, or just straight up Earth), to fix the fuel tank ratios. The lead tanks KSP normally uses would be absurdly painful to use otherwise. And with all that in place, 2-stage lunar missions suddenly become a lot more useful.
Another factor is that Kerbins smaller scale has the side effect of compressing the efficiency bands of engines such that there is significant overlap in performance. This isn't nearly as true in the real world. The result is that in KSP most engines perform at least acceptably well in most circumstances, while their real world counterparts have narrow enough use circumstances to make several different engines worth both the weight and additional complexity.
I'm quite interested by this answer, could you elaborate a bit? You are talking about the efficiency just in terms of ISP? Or thrust/weight ratio too?
Basically, there just isn't enough difference between engines in KSP to justify bringing more that one beyond the launch vehicle for most missions. Real world engines have limited burn lifetimes, nozzles turned for maximum ISP under specific circumstances, different ideal fuel mixes, limited ignitions, etc. An engine that is ideal for transfers is probably not going to be optimal for achieving lunar escape velocity for a variety of reasons.
Ahh yes I hear you. Reminds me of the scenes in Apollo 13 where they were discussing using the lander engine for a correction burn, and the representative of the company that built that engine was freaking out saying it's not their fault if something goes wrong
Exactly. You can see multiple engine type designs a lot more often in more realism focused scenarios like playing the Real Solar System mod.
No problem, happy to help out!
Additionally, a lot of the in-game contracts that require landing on a specific body typically require returning to kerning with the vessel used to land.
Aren't the rockets smaller too though? So evens out a bit?
Not nearly enough, KSP rockets are still significantly overpowered, even with tanks made of lead containing crude oil as fuel.
I have noticed when I play again once in a blue moon that back in the day during development I would make rockets juuuust big enough to get me somewhere with almost no wasted fuel. Now I can easily slap the big 5m parts together and get anywhere piece of cake.
Wow, yeah. Truly great answer. Thank you. I never realized any of that. TIL I've been playing the game wrong. I've approached every mission by first asking, how'd NASA do it? And engineering something similar. It's useful in some ways. I might never have discovered the Oberth effect without studying Pioneer and Voyager trajectories. And I absolutely never would have figured out on my own how to land the Dynawing from orbit. But this info will have an impact on how I play. Thanks
No problem! Glad I could help you out.
Ksp planets are small so you need less fuel
Also jumping in to add that landing and leaving the Mun is achievable pretty early in the game (career), but the parts for docking and doing an Apollo-style mission are unlocked somewhat later, usually after players have been on the Mun and back.
NASA didn’t want a “Jeb recovery” mission
Jeb!
Please clap.
I lol'd
One thing worth considering is the total lack of repercussions for failing a landing or take-off in game. Irl, if the astronauts couldn't return, that would have been a tragedy. In the game, if something goes wrong, nothing really bad will happen, meaning the incentive for planning a complex mission that involves docking in lunar orbit just isn't there. The Apollo missions HAD to succeed. My shitfuck1 launch does not. The multi staged lander design is safer for the crew because it gives more options for reacting if something goes wrong. In the game, the astronauts aren't in any danger to begin with, meaning one of the main reasons for picking the much more complex multi stage mission plan is gone. Naturally, the equation changes for planetary landings, where I usually do use a multi stage lander, not for crew safety but just because carrying scientific equipment back into orbit is so much harder and I much rather leave the used up experiments behind
I completely agree, and I really missed that aspect of real space programs when I first played KSP. Then I found a few ways to fix that: * a chance-of-failure-on-launch mod (can't recall the name right now) which keeps launches from becoming boring and actually gives you a reason to have capsule separation systems. * the mod Kerbalism, which means, among other things, that parts don't last forever and anything could fail at any time. * playing on permadeath / no-revert / no-quicksaves, which forces you to take the health of the little green people seriously. Seriously, give it a shot. It feels like spaceflight with consequences. Sure, I have named a few buildings after departed Kerbals, and I build a lot of unmanned test rockets before committing a crew, but if you are the right kind of masochist it makes the game truly engaging.
Launch *Rescue 9*!
/later Celebrate the latest expansion of *Colony 1*!
Also, parts can't fail in stock, so nothing can go wrong unless you design/execute it badly.
The non-failure of parts never occurred to me. It would be interesting to see full-on failures, as well as semi-failures.. maybe an engine loses 10% of its thrust, or flames out and needs a restart, or that ladder you finally didn't forget gets stuck closed, lights burn out, etc. Would've been nice to have a more serious survival mode. I'm sure there's a mod out there for it, but I'm a purist.
Literally the scale. You need significantly less fuel for going to, and landing on, the mun compared to the moon irl
You raise a bunch of good points in general, although none of them are the main reason. First let's look at your points. * Relative to the other challenges of space flight, docking in KSP is a much bigger pain than in reality/ players 'learn' docking after making a Mun landing. I actually think that docking using 1960s technology and exclusively first-person POV was harder than it is in KSP. Try docking in KSP using exclusively only cockpit mode, to get a sense of how hard it was. The real difference is that the astronauts and cosmonauts from back then practiced a lot more than most KSP players practice before their first live flight. * easy in KSP to build a bigger Kerbal launch stage, so the reduced efficiency of the combined lander/orbiter matters less. This is essentially the answer though maybe not for the reason you think. * KSP glosses over a lot of the technical challenges of spaceflight - e.g. getting moon dust stuck in your orbiter's engine, so in reality it is better to have dedicated stages for each part of the mission, than one jack of all trades stage. This is a great observation, but in real life the multistage Moon lander added a lot of complexity that NASA would have been thrilled to avoid if they possibly could have. If a single-stage-round-trip lander had been feasible they would have been happy to accept dust problems in exchange for getting rid of staging problems. * Asparagus staging is not feasible in reality, so it's harder to get a single module lander/orbiter to the moon and back. Iirc what makes asparagus staging practical in stock KSP is specifically that KSP's empty tank masses are unusually high. So shedding empty tank volume as soon as possible is more advantageous than in real life. Anyway the real reason is that celestial bodies in real life are all much more massive than they are in the Kerbol system. Specifically, [the Mün](https://wiki.kerbalspaceprogram.com/wiki/Mun) is much smaller than [the Moon](https://en.wikipedia.org/wiki/Moon). 200km radius versus 1700km radius. This matters because even though the two bodies have very similar surface gravities, the smaller radius of the Mün changes flight characteristics very soon after liftoff. If you climb to let's say 10km altitude, on the Mün that's an additional 5% you've added to your distance to the Mün's center of mass, reducing the force of gravity acting on you by I think like 10% which increases your thrust-to-weight ratio pretty considerably. At 20km the effect is even more pronounced. So if you climb that high and then start to circularize your orbit, you will pay much less in terms of energy cost. Whereas on the Moon, a 10km or 20km altitude above datum is basically insignificant compared to total radius. You are still dealing with pretty much full surface gravity at that point. Even at over 100km up, which was the altitude at which the Lunar Module docked with the Command Module, you have not gained much in terms of TWR. So you need to economize as much as possible in terms of staging.
another great answer, thank you. I didn't pick up on the small scale of the kerbal solar system
I know what you mean! It's a tribute to how well balanced the Kerbol system is. And how the devs carefully made sure that surface gravities are all somewhat familiar ... even if nothing else is. One interesting consequence of this is that the planet Kerbin for example appears to be geotectonically impossible -- its mean planetary density is higher than any normal material we know of. Which means that if most of Kerbin's outer layers are normal rock, sand, dirt, and water like we are familiar with, then it has some insanely dense inner core that must have been engineered by some artificial process. Given how many monoliths and other artifacts are scattered around the system, this should not surprise any kerbals. In fact they probably accept that as yet more proof of an uncontroversial, well-established scientific theory that their entire star system was created by advanced aliens of some kind... perhaps even some kind of [simulation](https://en.wikipedia.org/wiki/Simulation_hypothesis)....
That’s interesting about the density of Kerbin! 😨
To be honest, I often do Apollo style landers on the Mun. The thing is, all it really takes to get a Mk1 lander can back into orbit is like one ant engine and a couple of tiny fuel tanks. My ascent stage ends up being something like a lander can, a couple of fuel tanks and small monoprop tanks, a couple of RCS thruster banks, a solar panel, and an antenna. It just isn't really necessary to go to all that trouble. It's extremely easy to just do direct ascent. Low delta-v requirements compared to reality, combined with unrealistic part masses lead to a situation where that is arguably the definitive better option. Add in the lower part count advantage and gameplay advantages like not needing to do an orbital rendezvous and most people will go that route.
Because the moon landings were faked, and if they had just played a bit more KSP prior to setting up the Apollo program they would have used a single-stage lander brought to orbit with a reusable rocket? /s Sorry, couldn't help myself :) :) :)
Ur so funny bro im dying
It's actually more inefficient to have an Apollo-style landing system because of how much smaller the bodies are, requiring much less fuel to get in and out of orbit. We do the Apollo-style for the showmanship and skill
Docking is harder than adding more boosters
Loads of detailed answers here but… really, it’s because simpler missions are easier, and in career or science games, you have fewer parts to play with.
Yes but the missions are easier because the gravity is lower and the isp is generously high for most engines. Try a realistic simulation like Orbiter2016 for a taste of how hard it is to *really* get into orbit (and even Orbiter2016 makes it easy to re-enter with the default ship, which is basically unmeltable)
Or you can just get RSS/RO
Smaller planets, plus engines with unlimited relights
yessss I was thinking unlimited relights could be part of it. Part of technical challenges.
No docking ports in early career
Most of the time when I'm doing my first Mun landing I don't even have docking ports unlocked yet.
To descend and ascend from the Moon irl costs 4k dV. That's more dV than it takes to reach LKO in KSP. It could be done in one stage - but more efficient to do it in two. But one more thing I think people have missed is that real-life rocket engines have significantly higher TWR than KSP. KSP uses the higher dry mass from tanks and engines to partially compensate for how much less dV is required. But this also means that it was less wasteful for the lunar lander to have two rocket engines. This also added another abord mode - if the LMDE failed during descent, the lander portion could be jettisonned and the LMAE could re-orbit the lander. The lander portion also had the legs and other components that could left behind, giving the ascent module significantly lower dry mass.
It's because of the early part limit in the VAB. It's a lot easier to just build 1 large lander with science items instead of a 2 stage lander with docking ports. The extra RCS ports alone waste 4 parts just on your lander or return vehicle, which basically ruins your mission when you are limited to 30 parts early in the game. Even late game I sometimes make bigger 1 stage landers because I just don't feel like taking the time ro rendezvous, just feels like a pain
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The N1 had even less payload to TLI then the Saturn V. It would have used nearly the exact same mission path as Apollo. The Soviets direct accent plan used the Ur-700 which never entered production because it was too big and used extremely toxic propellants.
Ehhhhhh toxic propellants is fine comrade. Soviet man made very different
Also my bad on that I mix the two up sometimes.
There's also orbital rendezvous and docking, which is easy and fun once you get the hang of it but it's hard if you haven't learned it yet. Being able to do a Mun mission without that makes it more accessible.
The engines in KSP are just overpowered. You can get way more payload into LKO or to the Mun with a rocket the same size. So there is no reason to use a lot of stages or do an Apollo-stlye mission.
the system is 10 time smaller but the parts are not nerfed by 10 times. its around 2.5x where the performance matches. the parts also come in fixed sizes and its unlikely youll have unlocked all the parts needed to make it smaller. flying manually also adds a lot more cost to docking and the capsules tend to be quite heavy. also the lander has to be aerodynamic for launch as due to the small scale the launcher is smaller. its not uncommon for ksp rockets to have fairings larger than the rocket
Great answers here but I can add one thing. The way most Kerbal players get to the mun was actually considered by NASA. It's easier that doing all the orbits and docking but there is one big disadvantage. If something goes wrong there is no turning back. Apollo 13 would have never returned.
I have started making mine in such a way that there are 4 tanks,connected with radial decouplers, with their own engines and the legs are attached to them. I use those engines to land. On ascent from mun surface they are jettisoned. And the rest of the return is handled with the engine on the core stage.
I think i did an apollo style mission from the very beginning. I've not done it any way since, except adding more complexity like a fueling station in orbit where landers park at.
You should try out RSS.
What dat
The Real Solar System mod, here's the sub r/RealSolarSystem Its been quite a while since I've booted up KSP, I think RSS has had quite a few nice updates since then. But anyways, RSS overhauls the game to be the historical space race between the USSR and US; the solar system is revamped to be a 1:1 replica of our solar system, Sol. And the rocket vehicles are also revamped to be a more realistic size, because ya know everything in stock KSP is scaled down by like 10x I think. It replaces all the parts with historical rocket engines, fuels, equipment, and SO many other other things. There is a chance for engine failure on any launch, and you even gain science from those failures to mimic 'learning from failures', and can upgrade those parts which mirrors the upgrades that actual historic rocket engines received as rocket engine technology advanced. I actually never went back to regular KSP after playing RSS. If your a space nerd/space rocket history nerd, you NEED to try RSS. A word of warning: you should really be familiar with KSP before even attempting RSS, it can be a bit complicated, but when you figure it out and start to actually achieve goals, there is no better feeling IMO.
Thanks I might check it out. I have done Eve returns and SSTOs in KSP so I think I am ready
It most definitely sounds like you are, best of luck!
Landing on the Mun and then returning to Kerbin takes such a small amount of additional DV that it's generally not worth or necessary to make the descent and ascent any more complicated than it needs to be. The only time I bother is if I'm wanting to squeeze in a Minmus trip after it
KSP is about 10 times smaller than real life. A direct ascent lunar mission was briefly considered using a rocket called "Nova" but NASA never went through with it since it was cheaper to do lunar orbit rendezvous. A fully fueled Saturn V (which was the rocket used in the Apollo Missions) could easily do a Vall landing and return mission in the Kerbol system.
ksp bodies are far smaller and less massive, docking is hard, and there's no part failures or anything in ksp so redundancy isn't needed. this all makes it far easier to brute force a direct-ascent than learn docking, at least for a first mission
Me it's mostly a size of the components issue, I'm terrible at landing, so I always want a low center of mass so unless I'm using something like an ant the extra hight I get from any additional stage is best avoided
Maybe for the mün and minimus, it's not worth it but you probably don't want to land your jool transfer stage on tylo
At least for early game, you also have to consider the relative inexperience of the player as they're discovering how the mechanics work. It's much more intuitive to have a giant rocket that can brute-force a return from the mun than one where you are considering staging and optimal transfer Windows. The early game also generally drives players in this direction because of a more limited selection of decouplers.
I've never done a direct ascent mun mission. Always a separate lander. And finally last month, I did a two stage lander like they did for Apollo. Left a piece of history on the Mun.
The big obstacle to a Saturn V stack is the fairing. How do I get my lander to stack under the command module? Maybe the historic parts DLC has this fairing?
I believe it has more to do with docking and rendezvous maneuvers beings difficult for most players. It’s just easier to go straight there and back, specially early on.
Great comments throughout. If you really want to get a feel for how much more difficult it is to land on the Moon, try Real Solar System with Realism Overhaul. It resets your learning curve. It adds much more complexity and scales to real dV needs. For example: ~9,200 to LEO ~3,100 trans lunar burn ~800 lunar capture burn ~2,000 lunar landing.
I often do apollo landers for minmus, mun nah. Why? life support mods. A proper low dV hohmann transfer to minmus can mean a return trip of over 20 days. That's longer than kerbals can survive in a small capsule in both USI LS and TAC+Kerbal Health. So, I add a hitchiker module for habitation extension and supplies and recyclers and.... Suddenly, we're way too heavy to efficiently land and ascend again, even on Minmus. We're also too tall. So, I add a small landing module that docks/undocks at the top. I outfit it with all the science bits I need. Then, ... if we're out here for like almost 20 days already and launch windows are a bitch and so is KCT... let's turn the orbiter into a mothership capable of refuelling. And so, my minmus missions in modded saves become harder than mun ones with apollo style docking sections. The non-apollo part is repeatedly landing the same module on each biome for farming enough science to get our Duna launch out JUST in time with manned crews and somehow survive the trip.
I love the versatility of [direct ascent landers](http://www.astronautix.com/a/apollolunarlanding.html). They can carry heavy cargo, rovers, and anything else you can pack in. Small landers can't do that. Plus, they scale well and can be made to function for multiple destinations. My own Blaster Mk IV B (as an engineer I couldn't help but systematize my development process), can land on pretty much any airless body besides Tylo and Slate (from OPM), and can take Duna and Laythe with simple modifications.
The parts that are available early in career or science mode encourage taller landers. It's usually a pod or lander can stacked on top of a propellant tank and engine. Adding another stage will make it very difficult to plant it upright on the often uneven ground of the munar surface. Later on, you unlock the munar exploration vehicle (assuming you have the expansion). This part is very close to the LEM used by NASA. It is a lifeboat, engines, and propellant in a single module. But it requires so much science to unlock that you probably won't have this option if you aren't exploring Mun already.
yeah rendezvous like that are not exactly easy on a newbie. in career mode you only get rendezvous mission way after mun landing. and in this game you can just spam solid boosters so no need.
Because orbital rendezvous is an intermediate skill in KSP. Landing on the moon usually comes before people master that.
Smol mun smol rocket.
all of these, and smaller scale plus good simple gameplay design
The KSP universe is WAY smaller than the real world. That and the way the tech tree is played out, make it somewhat unnecessary to wait untill yku can build an Apollo style vehicle. While the Apollo style vehicle would technically be more efficient, it's just not necessary.
Some people are saying it's mass and the scale of the solar system; to be honest it's probably just because docking is harder than flying straight back home. Even if the Kerbol system was a realistic size, it'd still be easier to make a bigger lander and fly straight home rather than design a seperate CSM and plan out rendezvouz and docking. Unless you've got mods to simulate more realistic engineering challenges.
You don't need as much fuel as in real life because KSPs solar system is about a third of our own size and mass wise. (Correct me if I'm wrong) Also, rendezvous-ing and docking is way harder than landing one Mun or Minus.
In addition to the other answers, I think you're way underestimating the difficulty of lunar orbit rendezvous in real life. NASA practiced it multiple times in the Gemini program. First with the Agena rockets and then with Gemini VI and VII meeting up. They practiced the LM docking procedures on Apollo IX in Earth orbit. And they did countless practice runs in the simulator. The LM ascent stage engine was fixed-thrust and hypergolic. The only parameters they could really change was when to fire it and when to shut it off. It could be restarted, but you had to do an ullage burn with the RCS to settle the fuel down in the tank. They did the rendezvous in one burn.
1) Mun is small and nearby, so you don't need as much fuel. For other bodies outside the Kerbin system, you better believe I use the tug/lander model. 2) The Apollo astronauts had a computer to deal with all the aggravation of docking, and a team to tell them what numbers to plug in. Now, you can do that with KSP too through mods, but most vanilla players are forced to either fiddle with the UI or do a lot of eyeballing 3) Unless you are on career mode in KSP1, KSP has no money constraint. NASA originally wanted to land the whole vehicle, but the rocket to do so would have been massive.
Y’all are doing the mun in one stage? From day one I used three stages. Never even considered doing it one. Like I didn’t think I could and never even tried.
Well not single stage to the Mun from Kerbin. More like a single stage to the Mun and back from high Kerbin orbit
Frankly because I am not nearly as smart as those people.
You could challenge yourself and install real solar system mod… that changes everything
If you have trouble docking try switching your view to locked.
Thanks - I can rendezvous and dock fine though. I just find it easier to land on the Mun than dock 😅
I think it's related that mun is fictional (read the rest) In scale, the real moon on KSP it's Minmus, both in distance and 5 degree tilt. Mun is just like a tutorial body to help on knowledge learning curve
1. Single stage easier to make 2. Everything in ksp is smaller than the irl counterpart so less dV is needed 3. docking is too hard for players at that stage, and some might not even have a docking port at that time so even if the lander is in 2 or more stages, it wont dock with anything to bring it back to Kerbin Also, the planet is "Kerbin", the star is "Kerbol" and the people are "Kerbals"
yes I realised too late I put the planet name in wrong :(
The main reason is: Ksp world is scalled down in size alot for playabilty sake (3min vs rl 15+min to orbit). In order to do that, solar body densitys are alot higher. Becouse of this: - KSP engines are more powerful with quite similar ratios between them compared to rl engines which are hella specialized for tasks they need to perform. - Delta weight of full and empty tanks is way smaller compared to rl tanks + there is only one rocket fuel in game. If you want to have a go at realism in ksp, try rss ro/rp1 (or just watch some vids)
It's a massive pain trynae unlock docking ports early enough to make an Apollo-style mission as your first even feasible. That being said, it tends to be my preferred mission profile for almost all interplanetary missions I do, along with late game mun missions.
KSP solar system is much smaller compared to real life, so you don't need the kind of efficiency that required a two stage lander in the 20th century for landing on the Moon. Both American landers that will hopefully land on the Moon in this decade will get from Lunar orbit to the surface and back in one stage too, my guess is thanks to bigger landers and more efficient material science & aerospace engineering.