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Making it to the Mun...and Back?


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First of all, yes, I'm new, and my current goal is of course to make it to the Mun safely, however, after coming very close I've decided I don't want the poor guy tasked with the journey to be stuck there so I want to make sure he can return to Kerbin..

The question: Would launching a rocket into Kerbin orbit that is only for fuel work if I docked to it?

And how do you refuel in space?

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To get to Mun, you usually don't need a refueling ship. Assuming you're using the 1-man pod, and have a reliable launcher set up, just slap an FL-T400 and a nuke engine on. This can even get you to Minmus.

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Yes, you can put a refueling station, or just one Rockomax X200-32 fuel tank, in LKO (or Mun orbit) and then dock to it with your lander. Just make sure you put docking ports on both. To transfer fuel once docked, press alt+right click on the fuel tank and again on the lander's tank and you can see the fuel transfer window.

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Very helpful guys! I was a bit reluctant to ask such a nooby question as I felt the answer would be somewhere around here, but I couldn't find it.

_____

Razor, I want to do my best to insure the pilot makes it back safely as well.

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In that case, use the T400 + nuke for transferring, braking into orbit, and slowing before landing. As for the lander, just another T400 and an LV-909 can get you onto the Mun's surface and back into a Kerbin aerobrake, with a little fuel to spare.

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Learning to refuel in space is a good learning experience and something that will let you do a lot more than going to the Mun and Minmus. Granted, landing on both these moons are a learning experience in themselves but if there is one thing you will do as a new Kerbonaut is USE LOADS OF FUEL.

So my advice is to get a rocket with a decent amount of fuel into orbit. Make sure it has a docking collar attached to it (normal or JR size - just take note because your Mun ship will need the same size docking collar... oh and the shielded docking collar is compatible with the normal collar but not the JR one) and then send up your Mun ship up to dock with it to top off the tanks. So many of us (yeah, me included) end up landing on the moon (or crashing lol) and find we don't have enough fuel to get back to orbit.

And yes, docking is hard to begin with, but if you have problems just watch some videos (ie of Scott Manley's pedigree) and read up and finally if you are still having problems JUST ASK. The reason so many people help with this game is because it isn't easy right off the bat... but it is easy once you get the first few docking under your collar. If you are not a purist and will use mods, get the Romfarer Docking Camera mod. It helps with docking a LOT. http://kerbalspaceprogram.com/lazor-docking-cam/

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If you're really interested in practicing without a live Kerbal on your lander, I'd suggest using a Probodobodyne OKTO probe with 4 PB-NUK Radioisotope Thermoelectric Generators attached as your command pod. Unmanned; nobody dies when you plow that thing into the Mun the first dozen times, and when you think you're ready you can swap it out with a Mk1 Command Pod - it's the same mass as the OKTO/PB-NUKs.

If you go the docking/refueling route, I'd suggest practicing with the Gemini 6A/7 tutorial on the wiki. It'll teach you everything you need to know. Really, docking's no biggie as long as you take it slow.

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The satellite fueling station approach is simply a failure as I can't get it into a full orbit due to lack of fuel.

Any tips there? I can reach 100km but it's at that point where the small rockets come into play and they aren't enough to get me into a full orbit. Anything bigger requires more fuel to and more fuels weighs down the rocket even more.

Here's a picture.

2TG9b.jpg

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Your second stage (with the six 3200L tanks, each with their own Mainsail) is massive overkill. If you're close, you might get there just by removing every other Mainsail on that stage and adding fuel lines so you have three pairs of tanks each feeding a Mainsail. Fundamentally, other than your first stage, you have way too much engine for your fuel and you don't need that much TWR.

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So much advice! Didn't expect so many different avenues, thanks guys, now it's time to blow up a few rockets. :)

No worries, we were once like you.........we just outgrown the sadness of seeing our brave Kerbanauts spiral to their fiery deaths as their ship plodes high above Kerbin.

Try this as a guide.

http://wiki.kerbalspaceprogram.com/wiki/Mun_Landing

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You're taking on way to much at one time. You haven't make a Mun landing yet, and you are going to dock a lander to a relatively heavy payload. Just make a really minimalistic lander, that you think you can get to the Mun, and land. And then (hopefully) make it back. Unless you learn to dock without too much trouble, then just do the re-fuel.

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Yeah, I would skip the refueling part 'til after you feel comfortable doing a normal landing and return on the two moons. Thats taking too many steps at a time.

For the first travels go with a simple design that will get you all the way there. A 3-stage rocket with a decent lander with enough fuel is something I would reccomend. And try to learn how to control the spaceship, and how to do a properly gravity turn and gettign into orbit without wasting to much fuel. This will make everything easier for you in the long run.

Edit: Also keep in mind that due the position of Minmus and the low gravity of Minmus you need very little fuel to get back. I usually think I got way to little fuel, but when I get back I still have fuel left :)

Edited by etse
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The satellite fueling station approach is simply a failure as I can't get it into a full orbit due to lack of fuel.

Any tips there? I can reach 100km but it's at that point where the small rockets come into play and they aren't enough to get me into a full orbit. Anything bigger requires more fuel to and more fuels weighs down the rocket even more.

Here's a picture.

2TG9b.jpg

First, i know it takes a while to leran how to do it , but try asparagus,there are a few threads here already

Second,the second stage needs 2Jumbo tanks and 2 Mainsails, you get less thrust but you dont really need all that much power.

I can show you some examples later if you need.

Good luck!

Sorry for the tipos, this keyboard is kindahard to use

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I was a bit reluctant to ask such a nooby question

This is help/how to, it's what we do. I wish more people would stop using the General Discussion as a Help/How To... If I ever became a moderator I couldn't help but moving ALL of those question-like threads into the proper section.. So, props for using the right forum. I wish more people would ask questions here like you.

Anyhow, Mun landing isn't too horribly difficult. I tend not to do things by actually looking at how much Delta-V I'll need, but rather on a "Does this look like it'd work?" and then subsequent trial and error method. Here's my latest manned Mun mission with a three-man crew, Apollo-ish style. If your craft looks like this, you should have plenty of fuel to do all your stuff, even if you're not quite as good of a pilot as me. (Sorry, that sounds conceited, but I like to think I'm pretty damn good at controlling my craft.)

Be advised that this mission had an appropriately sized lifter that did MOST of the transfer burn TO the Mun. This small craft you see below did a tiny bit of the transfer burn, and the rest of the mission..

QtyawnK.jpg

Decoupling the lander with 2 Kerbs on board to go down to the surface. One Kerb is left on the transit vehicle:

zDyLJTB.jpg

Landed safely. This lander could actually have probably stood to use the smaller fuel tank, but this was my first manned Mun landing, so I wanted to be absolutely sure I had fuel to screw up with. I suggest you do the same.

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Doing some science:

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The top part of the lander detaches and easily makes it to LMO to rendezvous with the OTV...

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...And Kerbals are transferred over via EVA..

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This is left behind in orbit...

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...and this on the surface...

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I actually forgot parachutes and a decoupler on the OTV's capsule, and I didn't want to risk attempting to do a powered landing with the NERVA and ruin an otherwise perfect mission. However, I believe if the NERVA had the thrust to slow them down sufficiently, it DEFINITELY would have had enough fuel. Here's the retroburn after coming back from Mun orbit:

xP6dkKv.jpg

So how did I get Lozon, Kirk, and Erfel out of space? Here's the fun part: I didn't. They're currently aboard the Stability-9 station (which is, like all my other stations, basically a long tube that can hold Kerbals and have ships docked to it) which they docked using their OTV's remaining fuel and docking port. A bit improvised, but there is plenty of other company aboard the Stability-9, as well as two other OTV's: A small manned vehicle used locally for long-distance crew retrieval/transfer where docking would be too dangerous, and an unmanned tug used to either pull stranded vessels to somewhere new, or refuel them with some of its own resources:

38Wt0vM.png

Hope the pics were helpful.

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Wow, your refueling vessel is larger than my one-man Mun craft... :)

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You actually need very little fuel to get back from the Mun if your lander doesn't weigh much. A small spacecraft is exponentially more efficient than a larger spacecraft due to diminishing returns on added mass (you're adding engines and fuel to lift more engines and fuel, not payload).

My suggestion is to skip the whole on-orbit refueling aspect and just do a direct landing and return with a small craft, at least for your first Mun mission. It minimizes the number of things that can go wrong. :)

And definitely keep asking questions. We wouldn't be here if we didn't like talking about this kind of stuff!

Edited by RoboRay
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Here's a picture.

Where's the top half of the rocket?

The biggest tanks in your game should only be attached when you're well down the staging list. Attaching them in stage 2 is massively inefficient because of the massive amount of dry weight and will cause no end of fuel and stability problems.

For a basic mun mission you shouldn't be touching the larger diameter tanks at all, it's perfectly reasonable to do a 3 man mun mission with a handful of engines and just 1.25m tanks. Just start small, When you've got 400L of fuel left you should be pushing 200kg of fuel tanks, not 5 tons worth.

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Uh-huh.......yep................that's a nice space station core you've got there.

For your first Mun missions, RoboRay's design is what you want to shoot for. If you want to go fancy with it, replace the center fuel tank with an FT-200, put three or four more FT-200s on the sides and hook fuel lines from the outrigger tanks to the center tank. Put your lander legs on the outriggers. This shortens the overall length of your lander and widens the base, which really helps when you're making Mun landings.

Oh, and OKTO/4 PB-NUKS if you want to make a couple of unmanned practice missions first.

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Agreed... a wider base makes landings a lot easier, especially when you haven't managed to zero out your horizontal drift. I was just trying to see how small I could possibly make a craft capable of that mission. :) Using the smallest tanks in the tripod arrangement around the core would give you plenty of reserve fuel, as my design is close to the margins on delta-v requirements (I think I had 60m/sec remaining when I jettisoned the lander). I doubt the launch-vehicle requirements would change much.

If you put the outrigger tanks on small radial decouplers, you can dump them after you take off from the Mun and they are empty, saving you a little more fuel on the way home.

Edited by RoboRay
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as some said before you try to do way to much at once. The most important thing is to read into the manouvers you need to do and how to fly to save DeltaV. Start to learn how to do a gravity-turn, how to get to the moon using manouvernodes, how to burn to land on the moon from an orbit and probably most important how to return from moon to Kerbin (thats a point wich i screwed up so often i can't even count because i just didn't know how to do it the right way) Most parts and fuel of your rocket are only for achiving an orbit around Kerbin. Once you got that done it's just a matter of how much deltaV is left and if you can make use of it.

And another important point: Try not to use to much Engines and Fueltanks. I started with the same mistake but you realy don't need so much fuel and those engines. Once you are in space it's not a matter of thrust but efficiency. one engine in orbit is more than enough.

Here are some shoots I made for you:

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A Simple design. No asperagus stage, just 1 Fuelline in the first stage. This thing is still a bit overkill for a munlanding but it has more room for error.

cvoTkTv.png

this is the ship after I got it into an orbit of 110km arround Kerbin. It has more than enough fuel to go to mun and minimus. The stages are:

current stage: a normal and a small fueltank with one Lv-909 Engine.

Lander: a normal tank with an Lv-909 Engine, ASAS and a decoupler under the capsule wich has a parachute on top. (+3Landinglegs)

9dMO9vN.png

uVR4vER.png

at a circular orbit around mun (50km), i still got more than enough fuel left. If you use the first stage under the lander to deorbit you can Land with allmost full fuel on the lander. You could probably visit minimus with that:

l6qAYgQ.jpg

So it realy comes down to maneuver and design of your craft. If you use to much fueltanks and engines it has the opposite effect of what you want to achieve so try to keep it small

Keep trying until you succeed my friend and have a nice day ;)

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Agreed... a wider base makes landings a lot easier, especially when you haven't managed to zero out your horizontal drift. I was just trying to see how small I could possibly make a craft capable of that mission. :) Using the smallest tanks in the tripod arrangement around the core would give you plenty of reserve fuel, as my design is close to the margins on delta-v requirements (I think I had 60m/sec remaining when I jettisoned the lander). I doubt the launch-vehicle requirements would change much.

If you put the outrigger tanks on small radial decouplers, you can dump them after you take off from the Mun and they are empty, saving you a little more fuel on the way home.

With the flat 2.5 meter tanks and thee small 1.25 meter tanks you get an very wide base. With the three man pod and a 909 you get over 3000 m/s dV enough to take you from LKO to Mun and back.

two orange tanks over mainsail and three large solid boosters take you to almost to LKO.

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