Questions for Realictis level of difficulty

[Catalyst_Kh]

Hello all. I recently discovered this nice game and played a little.

It was too easy on Normal level and Hard level was very little different, so i tried Realistic level.

I want to reach this goal at Realistic level: to send an astronaut to the Moon, land him there, and then take off from the Moon and return this astronaut to earth alive.

On Realistic level it is very hard to get away from the Earth, it burns all fuel, so the best i can do is to deliver 43 tons to the orbit of the Moon, no more than that.

Thus, the questions are:

1. Is it possible to bring more than 43 tons to the Moon's orbit in this version of the game? Should i try to invent a better rocket scheme? To try to bring more than 43 tons. Or 43 is already the maximum for Realistic level?

2. Is it possible to return to Earth with any rocket scheme, which weight is much less than 40 tons? Because i need to burn a lot of fuel for slowdown before Moon landing and after that i have only something over thirty tons left of total weight for taking off.

3. Would it be better to approach Moon directly to the center by "straight line" and slow down vertically before landing? Or is there a better trajectory around the Moon, to start moving in elispses around the moon before changing trajectory for landing? Which option burns less fuel and is more effective?

4. Is it possible to slowly build a bigger-sized rocket (bigger than blueprint rectangle limitations) by delivering components to the Earth orbit and assembling components somehow there into huge rocket on the orbit? For example, how to stick two fuel banks together on the orbit? I can push them by maneuvering engines, but how to assemble it in one construction, which can launch all together at the end?

Please help me with any suggestions. I played v1.5.8.5 version, if it makes any difference.

 

[Catalyst_Kh]

Is it possible to make a larger field in rocket constructor? For now, blueprint in rocket editor section is only 20x100 big squares, or 40x200 small "inside" squares (dotted lines). And i would like to make a bigger rocket, than that, to deliver more tons to the Moon or to reach other planets at Realistic level.

 

[Cresign]

Is it possible to make a larger field in rocket constructor? For now, blueprint in rocket editor section is only 20x100 big squares, or 40x200 small "inside" squares (dotted lines). And i would like to make a bigger rocket, than that, to deliver more tons to the Moon or to reach other planets at Realistic level.

Theres an option to enable infinite build screen in the cheats menu, even though it is there with other cheats, most of community agrees that it isnt giving you enough unfair advantage to consider it as something you should avoid in normal gameplay.

With that said, theres not really a limit to how big your rocket can be, so the question 1 is a yes.

I dont have the PC version so i can't answer the question 2, but question 3 - that doesnt seem to make a difference. Its mostly dependent on your thrust to weight ratio, if its low, your trajectory will naturally be more flat, but if its normal you can slow down how you want.

Question 4 - docking ports. Docking ports connect to eachother creating a link between two crafts. You need one port on each craft you want to connect to do so, and they have to face eachother. You can also undock (separate) them and redock again without limitations. To dock crafts together, you have to launch the first one, and then meet up with it in orbit using docking system. Select the craft in orbit and using transfer system you already know, burn towards it.

 

[Catalyst_Kh]

Thank you very much Cresign! One more question then:

I don't want to use cheat options, if that is possible. Did i understand correctly, that with fair play as it is i can simply assemble unlimited-size rocket on the orbit of Earth without any cheat options? It will just take some time to make it peace by peice, but it might be fun.

For now i made all optimizations i can think of with fair rocket and i can bring only 43.7 tons to approach the moon. At Realistic.

If anyone was able to bring more tons to the moon from earth without cheats - please tell here, i would be very grateful for any advices.

 

[Altaïr]

Hello Catalyst_Kh

Realistic level is the true hard mode, it's not surprising that you experience that kind of problems.

1. Is it possible to bring more than 43 tons to the Moon's orbit in this version of the game? Should i try to invent a better rocket scheme? To try to bring more than 43 tons. Or 43 is already the maximum for Realistic level?

To be honest I don't know what is the absolute maximum, but 43 tons seems like a good performance. I don't have access to my PC so I can't try, but I made a try on IRIS, it's a planet pack in which the scale is reduced by a factor 4 compared to the realistic setting, but as I don't get the engine buffs the difficulty is comparable. This is my launcher:


That's what I managed to send in Earth orbit:

That ship weighs 120 tons. It corresponds to the maximum capacity of my launcher. In realistic mode, the max payload to LEO is rather 100 tons, which gives an element of comparison.

Then this is what I have in Moon orbit:

The ship now weighs 46.5 tons. Applying the 100/120 ratio established above that would give 38.8 tons in realistic.

I could probably do better because I don't use the full build space (the build space was slightly smaller when I designed that launcher), I use "only" 5 Titan, but your 43 tons are a good performance in comparison.

However don't hesitate to post your launcher if you want some suggestions to improve it.

2. Is it possible to return to Earth with any rocket scheme, which weight is much less than 40 tons? Because i need to burn a lot of fuel for slowdown before Moon landing and after that i have only something over thirty tons left of total weight for taking off.

Usually this is not very difficult, even in realistic, but it also depends on your mission design. The most efficient way is to do it in the "Apollo" style: you leave a ship in Moon orbit, you land and return from the Moon with just a small module, then you dock your module to the ship left in orbit:

I've landed and returned from the Moon, and now I have more fuel than needed in what is equivalent to the CSM.

If you try to land a big ship on the Moon and return directly to Earth this will more expensive in terms of fuel. The Apollo strategy allows to leave in orbit the fuel you will need to return to Earth instead of landing it and returning it from the Moon, that's what makes it more efficient.

3. Would it be better to approach Moon directly to the center by "straight line" and slow down vertically before landing? Or is there a better trajectory around the Moon, to start moving in elispses around the moon before changing trajectory for landing? Which option burns less fuel and is more effective?

Never burn straight to the Moon, it's the least efficient method. Especially in realistic mode when you need to save everything you can. The best strategy is to reach low Moon orbit before everything:

Maneuvers performed while being close to a massive body are more efficient: this is the Oberth effect. That's why it's best to aim for a low periapsis and perform your insertion burn here. Then once you're in Moon orbit you can land on the Moon with a dedicated module.

4. Is it possible to slowly build a bigger-sized rocket (bigger than blueprint rectangle limitations) by delivering components to the Earth orbit and assembling components somehow there into huge rocket on the orbit? For example, how to stick two fuel banks together on the orbit? I can push them by maneuvering engines, but how to assemble it in one construction, which can launch all together at the end?

I'll make it short because Cresign already answered, but yes of course. This is not strictly necessary for a Moon mission but this will be mandatory for more ambitious missions.

 

[Catalyst_Kh]

This is my launcher:
View attachment 96027

At Realistic level this launcher will be able to bring only 30-35 tons to the moon's orbit, it will not reach even 40 tons. I tried bigger launcher like this form, with 7 starting engines of 400 ton each - at full width on blueprint sheet, and with height to the maximum - and it still brought only 40 tons top with all optimizations between rocket stages.

Thus i had to invent other forms of the initial launcher. It brings 43.7 tons to moon's orbit now, but it is still too little.

in which the scale is reduced by a factor 4 compared to the realistic setting

4 times more distance to get away from Earth gravity outweighs that a lot, with huge difference - it burns out "4 times more fuel". Engines weights have very little value here, since fuel weights are very much bigger, than engines.

Usually this is not very difficult, even in realistic, but it also depends on your mission design. The most efficient way is to do it in the "Apollo" style: you leave a ship in Moon orbit, you land and return from the Moon with just a small module, then you dock your module to the ship left in orbit:

Wow - that is super nice idea - thanks! And to do that i need to bring more than 60 tons to the orbit of the moon. And i stuck with 43.7 so far.

I'll make it short because Cresign already answered, but yes of course. This is not strictly necessary for a Moon mission but this will be mandatory for more ambitious missions.

Was here at least one case (like forum post or youtube video) of landing astronaut on the moon and bringing him back to earth alive with rocket launched from earth directly? At Realistic level.

Maneuvers performed while being close to a massive body are more efficient: this is the Oberth effect. That's why it's best to aim for a low periapsis and perform your insertion burn here. Then once you're in Moon orbit you can land on the Moon with a dedicated module.

So right from the earth i am aiming with ballistic trajectory, which will go very close near moon (instead of it's center) and then, when i will be near moon itself - i will push engines for slowdown to take a turn over moon and establish orbit, instead of going very far away from moon again (if not start slowing down).

Is that correct algorithm?

 

[Catalyst_Kh]

Maybe It would be also a good improvement to the game to make bigger blueprint sheet size for Realistic level, so it would not require so much to use cheating option of unlimited blueprint size. While for normal and hard levels current size is more than enough.

 

[Catalyst_Kh]

Altaïr, how do you think, would this be enough fuel for Moon mission with Apollo landing?

It weighs only 47 tons, which is possible to bring after some other improvements to the rocket structure, at least it is not 50+ tons.

If it is not enough, what would be minimal enough?

 

[Altaïr]

At Realistic level this launcher will be able to bring only 30-35 tons to the moon's orbit, it will not reach even 40 tons.

That was to have something to compare with since you asked if it was possible to go higher than 43 tons. But I didn't exagerate the performance. I made a quick calculation, from my ΔV map, it takes 829 m/s to go from LEO to LMO. If I apply a scale factor of 20, I have to multiply speeds by sqrt(20), which leads to 3707 m/s. If I use my ship design assistant:

With 100 tons in LEO I can send 37 tons in LMO, with a margin. This doesn't include the empty stage of course. I said 38.8 in my previous post. I'll give it a try when I have the opportunity, but you see I wasn't exagerating.

4 times more distance to get away from Earth gravity outweighs that a lot, with huge difference - it burns out "4 times more fuel". Engines weights have very little value here, since fuel weights are very much bigger, than engines.

It's not how it works, fuel consumed is not proportional to the distance
The engines weight is halved but this is not the only bonus you get in realistic. You also have +50% on specific impulse (which means that fuel consumption is reduced by a third), and the empty tanks are lighter too, they only represent 2.5% of the full tank mass (instead of 10%). It doesn't seem much, but for a fuel tank of 60 tons, you have only 1.5 tons of dry mass instead of 6 tons.

If I make the same exercise, in IRIS I have to provide 1854 m/s for the trip. With 100 tons from LEO, I can send 40 tons in Moon orbit:

40 instead of 37 means that I play with a slight advantage compared to you, but it's not that big, the experience is comparable.

Wow - that is super nice idea - thanks! And to do that i need to bring more than 60 tons to the orbit of the moon. And i stuck with 43.7 so far.

No, you missed my point. You can do that with a ship of 43 tons, but you split it in several modules. Look at my mission, that's what I did, and I have way more fuel than necessary to come back to Earth:

See, I had 46.5 tons in total when I reached Moon orbit, and I can come back with 78% of fuel in my tank, which represents 17.5 tons of unused fuel. I had a very comfortable margin!

Was here at least one case (like forum post or youtube video) of landing astronaut on the moon and bringing him back to earth alive with rocket launched from earth directly? At Realistic level.

Yes, a recent member did his team Titan mission in realistic:
Team Titan Entry

A few people did it in IRIS too:
My IRIS pack entry for Team Titan
Team Titan 2.0: Bigger and Hotter

I did it myself too:
My moon mission (IRIS planet pack)
With that rocket:

So right from the earth i am aiming with ballistic trajectory, which will go very close near moon (instead of it's center) and then, when i will be near moon itself - i will push engines for slowdown to take a turn over moon and establish orbit, instead of going very far away from moon again (if not start slowing down).

Is that correct algorithm?

Yes, that's correct.

 

[Altaïr]

Altaïr, how do you think, would this be enough fuel for Moon mission with Apollo landing?

It weighs only 47 tons, which is possible to bring after some other improvements to the rocket structure, at least it is not 50+ tons.

If it is not enough, what would be minimal enough?

You forgot a heat shield, as is you would have a problem to end your mission.

I made a quick calculation, with a lunar module like this one you have more than 4000 m/s of ΔV, that's way enough to land on the Moon and reach orbit again:

I did it in 2 stages because of the historical LEM architecture, but this is frankly not needed.

Then you can add a service module at your convenience, the one you built is perfect.

 

[Catalyst_Kh]

What i LEO and LMO?

It's not how it works, fuel consumed is not proportional to the distance

I know that of course, i put that in quotes there for simplicity, to not explain obvious things futhermore.

Thank you very much for all detailed explanations!

I want to try this one:

This one is only 42.9, so if i take such one, i will have some extra fuel in previous rocket stage, since it brings 43.7 with 1%-2% extra in the banks left. Thus with 42.9 i will have some more extra fuel lest and i can spend it for slowing down near moon, before detaching the stage, so i can save fuel in this low bank at the bottom on the picture.

Will this connection work at all? Will that be enough fuel for landing and coming back from the moon to orbit module? I will try and find out, maybe some improvements up to 45 tons will be needed and i can bring 45 tons and use just a little fuel from it to top up previous stage, which can only bring 43.7 now.

 

[Catalyst_Kh]

You forgot a heat shield, as is you would have a problem to end your mission.
I did it in 2 stages because of the historical LEM architecture, but this is frankly not needed.
Then you can add a service module at your convenience, the one you built is perfect.

Thank you very much! I will try this one.

And i forgot about heat shield completely. I can only imagine how much i would be swearing, if i would had successful comeback to earth and burn in the atmosphere without sheild.

That is my first guess to try:

It is only 41.7 tons, which means i will have a lot of extra fuel in next rocket stage before moon and will be able to spend this extra fuel for making Moon orbit stable, for slowing down and maneuvering to grab the stable orbit, and not using anything from that bottom bank at the picture.

 

[Catalyst_Kh]

Yes, a recent member did his team Titan mission in realistic:
Team Titan Entry

It doesn't says there, that it was at Realistic level. By the size of his rocket looks like he can bring only around 35 tons to the Moon's orbit at Realistic. Is it really enough?

Also i never ever saw this tabs in the game, which he have at his screenshots:

How can i activate those?

Plus there is a puzzle. From the structure of the starting rocket at his picture it strongly looks like he is moving fuel from side towers to central tower right from the start. I tried to do that and failed. So i had to stick with less efficient schemes - without fuel transfer.

For example, If i send fuel from bank A to bank B, but at the same time i try to send from C to D, or from C to B, or from A to C - in all those cases, as soon as i pick second fuel transfer - first one (A to B) simply ceases at all. Thus i can transfer only one line at a time and even at very low speed.

Is there a way to overcome this problem and transfer fuel in a better way?

 

[Altaïr]

What i LEO and LMO?

Oh, sorry. "Low Earth Orbit" and "Low Moon Orbit".

I know that of course, i put that in quotes there for simplicity, to not explain obvious things futhermore.

Oh yeah, I missed that

It doesn't says there, that it was at Realistic level. By the size of his rocket looks like he can bring only around 35 tons to the Moon's orbit at Realistic. Is it really enough?

I saw it judging by the orbital speed: he is at 7816 m/s in LEO, that's clearly realistic mode. I haven't tried to recreate his mission so I wouldn't swear, but I'm not shocked that he could do it with 35 tons to be honest.

Also i never ever saw this tabs in the game, which he have at his screenshots:

How can i activate those?

Those are mods.

The advanced info panel comes from Vanilla upgrades, and the other is the smart SAS.
They are not strictly necessary but they offer some welcome improvements.

Is there a way to overcome this problem and transfer fuel in a better way?

Sadly no, you can only perform a transfer at once at the rate of 1 ton/s. For a big rocket it's not much in comparison of the many tons of fuel guzzled by several Titan engines. The improvements you can expect from this are quite limited in practice.

 

[Catalyst_Kh]

Thank you very much Altaïr!

This fuel transfer is still useful thing - for example, i plan to refuel at Moon orbit after landing, to go to Earth with topped last stage. And since i can bring more tons to Moon i improved last to stages, added +2.5 tons of fuel and made it one useful horizontal row shorter. And each row gives a lot of help. Now it looks like this:

Didn't try to go to the Moon yet, was still trying to improve rocket to bring more tons. But seems like 45 is unreachable at all, only less than 45 at best. Thus it is time to take off finally.

 

[Altaïr]

Thank you very much Altaïr!

This fuel transfer is still useful thing - for example, i plan to refuel at Moon orbit after landing, to go to Earth with topped last stage. And since i can bring more tons to Moon i improved last to stages, added +2.5 tons of fuel and made it one useful horizontal row shorter. And each row gives a lot of help. Now it looks like this:

Didn't try to go to the Moon yet, was still trying to improve rocket to bring more tons. But seems like 45 is unreachable at all, only less than 45 at best. Thus it is time to take off finally.

Looks good! That should do the job

 

[Catalyst_Kh]

Looks good! That should do the job

That was not enough for me!

After i landed to the moon, took off and grabbed LMO - i had only 10% fuel left, from 15 tons bank, it is 1.5 tons only. I tried more accurate landing from queck save, but most i could squeeze was 11%, other times even 9% or lower.

These 1.65 tons of fuel simply was not enough for me to catch again my orbital Gas Station at LMO. I tried many times, but still missing it. And then i got the idea, that i can significantly improve the whole lunar complex entirely, which i bring to the moon.

But your theoretical calculations were correct and very precise - those 1.65 are totally enough to catch our orbital fuel canister, it just requires much more precision and dexterity than i can muster.

 

[Catalyst_Kh]

So, the first thing that came to my mind - why gas canister needs its own engine at all? I already have an engine at moon lander, then why not free up a lot of important vertical space in blueprint rectangle, not to mention a big reduction in weight by removing superfluous engine.

Then it came to mind, that my rocket design have extra horizontal space, which is unused, but each vertical square is very valuable, thus i need to save|reduce vertical usage as much as possible.

And then, since i freed up a lot of vertical squares - my rocket became more powerful and i can bring up 45.5 tons the LMO, according to my calculations in excel.

And thus i made this one optimized version:

Spoiler: Picture:

It is only 45.3 tons, thus i reached Moon orbit with even 1% of fuel in my previous stage or the rocket.

This bigger engine not only more efficient, which virtually makes even more fuel in banks, but even more important is that with such extra power i can beat Moon's gravity very fast both ways, which again saves a lot of fuel more.

Thus even with another game difficulty, where this engine will weigh whole 4 tons - it is still more efficient to use this one for Lunad lander instead of small Kolibri engine for 15 tons of thrust.

It was much easier with this module to catch again my orbital gas station on LMO and refuel there, before going back to Earth.

And also with smaller engine i would had total failure with slowing down near Earth - i accumulated huge velocity near planet, almost 11k:

Thus even if i was successful in catching my canister with old Lunad system in first fly - i would still had guaranteed failure near Earth. Thus Lunar system with smallest engine is just not good enough at realistic level, at least for this type of mission, since i have no extra fuel en route to Earth for long slowing down with small engine and big one is very light in weight at realistic.

 

[Catalyst_Kh]

Even with stronger engine i used all my fuel and still couldn't make LEO! So i had to change approach vector to go into atmosphere at high speed, without taking orbit, but it worked - i landed to Earth safely!

Thus thank you again Altaïr!

Some nice pictures from the flight:

Spoiler: Pictures

Catching up my orbital gas station - it was soooo much harder than i anticipated.

My module parts didn't detach at central white collar connection (at picture above), as was planned, since i had no more fuel to detach it before diving in atmosphere!

Thus those parts where overheating and exploding one by one, it made my module tumble furiously after each explosion and i barely was able to turn it with heat shield ahead in time to not burn my astronaut. It was very fun!

Some parts didn't explode and just were torn away, here they are:

 

[Catalyst_Kh]

Hello Catalyst_Kh
However don't hesitate to post your launcher if you want some suggestions to improve it.

I didn't want to show it before, since it was sooooo ugly - you can't even imagine. I was embarrassed to show it. And also it was very not optimal, it was work in progress, i improved it all the time and made many hundreds (!) of optimizations.

Now it is completed and i don't see what else i can improve or optimize there, plus i reshaped it a little, to make it less ugly. Here it is:

Spoiler: The whole launcher:

 

[XenonSpace]

Try to use less Titans, but more Frontier. It's much more efficient for second stage usage. Don't forget staging, as it will greatly help reduce dry masses of empty tanks and heavy Titan Engines when dumped. Your rocket is also not very aerodynamic, use fairings for the core stage so to not lose delta-v by atmospheric drag.

 

[Catalyst_Kh]

Try to use less Titans, but more Frontier. It's much more efficient for second stage usage.

I tried, but i didn't found any good way to make it. Please show it to me. For example, improve my design with Frontiers and show it here. Where they should be.

For me it was this way - i couldn't make Launcher better with Frontiers at any stage in many different configurations - launcher always loses efficiency a lot with any more Frontiers.

My Launcher with more Frontiers (than on the picture) can't even reach the Moon at all. Or in order to reach Moon i have to significantly reduce payload, which is total failure. Too much weight to carry for too long distance - only Titans can do that at Realistic level.

Any weaker engines actually consumes MORE fuel, than Titans, because they burn this fuel with making much less altitude and speed gaining, thus fuel is wasted inefficiently - fuel goes away to the garbage in order to fight against gravity for much longer period of time. While Titans bring much more altitude and velocity for the same fuel consumed, because they escape gravity very fast.

I even tried Titans in third stage too and it again was better, than Frontier in 3rd stage, but later i invented a better version of first stage and then all Titans from 1 and 2 stages made more momentum, which was enough to espace gravity. And only then one single Frontier became better instead all Titans.

Only because Titans in second stage and all other stages it was possible to bring almost 46 tons to the Moon.

Your rocket is also not very aerodynamic, use fairings for the core stage so to not lose delta-v by atmospheric drag.

Please show the way, how to place them on my model.

All ways i tried to place Fairing cones or white Nose cones - my Launcher became weaker and slower, every time, since it was losing very important fuel banks of last stages to free up space for any type of cones.

Whule launcher without central cones at all gives much more efficiency - it gains more velocity and more altitude, than anything with cones.

I even tried to make this variation (at the bottom):

In this case (bottom version) there was too little extra fuel gain, it was not enough (since it is only first stage) and launcher was taking off a tiny bit slower, thus i placed Cones, as on the top side of the picture - they still have room for some decent amount of fuel.

I don't know what delta-v is, i just want to make launcher faster and more powerful, so it could bring more tons to the Moon. So if you know how to add Frontier or central cones with gaining more altitude and velocity (instead of losing it) - then please show design picture with it.

 

[Catalyst_Kh]

I didn't found a way to edit my message. I accidentally misclicked the rocket model in game when i made a picture, and missed that i am picturing one of the older models. It has little flaw theres, which i corrected later. And i want to replace the picture in that message.

Here is correct version of the Launcher:

Spoiler: My Launcher for Realistic level

 

[Catalyst_Kh]

XenonSpace, here is the best i could invent:

Spoiler: Cone test:

Coned version is still slower.

It might seem not significant in comparison by mere numbers at the picture above, but this extra +1.5 m/s and Height is multiplied by entire distance to Moon - and at Realistic level this distance is huge, thus in result - the final number of lost efficiency is quite sensible, it affects delivered payload noticeably.

Look how much fuel the launcher lost to make up room for central cone. Maybe you know a better way to make it, please show it then.

 

[Catalyst_Kh]

I feel so silly now, i just invented a new strategy, which allows performing any mission to any planet at Realistic level right from Earth, without orbital construction. And it allows to land on the Moon and safely return home with much less than 30 tons of payload delivered to the Moon.

Very simple strategy, and very superb. I suspect some of you already knew that and intentionally didn't tell me, so i could have fun inventing it myself. step by step