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How to get to the Mun? Rocket Help too!


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I can get into orbit. My designs have failed so miserably..... yeah. I never took any screenshots, and had to re-download KSP with the new update because I was getting an error. =/ If someone could tell me how to build a mun rocket, I would use that the first time I try. After that, I would make my own.

G

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Just coming to .16 from the demo it took me MANY a trial to make a proper Mun/Minmus landing craft + return vehicle, but I haven\'t had a successful landing because I can\'t get rid of my horizontal velocity so when I land I bounce/fall over, but as far as getting there, obviously a one man Kerbal rocket is easiest (mine is for three), which would you like?

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Just coming to .16 from the demo it took me MANY a trial to make a proper Mun/Minmus landing craft + return vehicle, but I haven\'t had a successful landing because I can\'t get rid of my horizontal velocity so when I land I bounce/fall over, but as far as getting there, obviously a one man Kerbal rocket is easiest (mine is for three), which would you like?

RCS will help with that. Admittedly, less so with the new heavy parts, but if you use lots of thruster blocks to make it effective, it is a lot easier to fire directional RCS than it is to pitch over and use the main engine (I\'m assuming because you said \'bounce\' rather than \'violently explode\' that you don\'t have hundreds and hundreds of m/s to kill).

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RCS will help with that. Admittedly, less so with the new heavy parts, but if you use lots of thruster blocks to make it effective, it is a lot easier to fire directional RCS than it is to pitch over and use the main engine (I\'m assuming because you said \'bounce\' rather than \'violently explode\' that you don\'t have hundreds and hundreds of m/s to kill).

Its way easier to cancel your horizontal velocity with your engine as you burn retrograde to slow down for landing. RCS doesn\'t always burn off horizontal velocity as quick as you\'d like. It also requires you to figure out which direction you need to translate in. Here, I threw together a quick demonstration for you. Excuse the mistakes please, this was a seat of my pants video.

-Ziff

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Its way easier to cancel your horizontal velocity with your engine as you burn retrograde to slow down for landing. RCS doesn\'t always burn off horizontal velocity as quick as you\'d like. It also requires you to figure out which direction you need to translate in. Here, I threw together a quick demonstration for you. Excuse the mistakes please, this was a seat of my pants video.

-Ziff

General rule of translating to burn off horizontal velocity: Exactly the same as the controls for making your ship point in a different direction, but reversed (I and K are 'correct' but J and L are reversed, the exact opposite of WASD) and you can\'t roll. Is that really too complex for anyone?

And yeah, the engine does it faster, but you can translate while pointing in any direction.

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If you really want a short bit of coaching the tutorials are good. But here\'s my best go at a short description of how I approach it.

First build a lander. For first attempts make it small and light, that way it\'s easier to change velocity though they can be very sensitive on the controls. Try the smallest cockpit for one kerbalnaut, add one or more parachutes, then a decoupler, then an ASAS and say one large 'small' fuel tank and the smallest engine. For refinement add an RCS tank and say 3 thruster blocks. Add 3 of the larger legs (heavier but much more resilient, the small can be used but tend to break if you have any transverse velocity). That\'s the lander; might be a bit short of fuel to return, you may try a second small tank, experiment.

Next you need the motive stages, and this is often a case of trying a certain configuration and modifying. For first goes keep it simple. I\'d go for two stages here for simplicity, with one to launch and 1 to push you into orbit and to Mun. The second stage is, say a couple of BIG tanks and a big engine, attach with a small decoupler (I reckon these are more stable, but YMMV). When experimenting if you need stability add fins and struts for support, just be sensible. I\'d add fins for the early part of the descent too. First stage, try the same as the second plus, say, 3-4 of the larger solid fuel boosters, plus fins. Attach with small or large radial decouples, I like the small as they seem to detach better, but that may be just me.

Pay careful attention to your staging; have the first stage and the solid fuels in the bottom, then a decoupler stage to drop the solid fuels, then group the first stage decoupler with the next stage so you just drop the stage and keep going.

You may need more push, you could try a small third stage above the second, but experiment, you can often add solid fuels for just a bit more but try not to get too complex.

As you go up, start to head North at any time from 8,000 metres up, might be best to wait until 12K or 16K, but I\'d say definitely by 30-35K where you can be over by 45 degrees. This reduces the 'gravity drag' and reduces fuel burn. Wait until you have an apoapsis of, say 80K (suit yourself on this, can be as low as 70 or as high as 100-120 to 240 if you have plenty of fuel). Stop burning and coast until you are at the apoapsis ( 10 or so secs out to give yourself a little margin) and be ready at close to a horizontal burn, a little up and adjust down as you go, try to keep close to the apoapsis until you get a periapsis and burn until that\'s above the atmosphere. Your now in a stable orbit around the equator or close to it.

To get to Mun, slow way is to go to your periapsis and burn towards the round green circle on the control ball or whatever you call it. That will extend your orbit on the opposite side of Kerbin, push it out until it intersects the Mun\'s orbit, and warp time until you pick up an intersection with Mun. Faster way is to go into the rocket view, orient yourself until you are pointing at the green circle in your orbit and change the view to look forward at the Kerbin horizon. Wait until Mun rises and immediately burn at full thrust. You should intersect with Mun the moment you orbit crosses Mun\'s.

I\'d then warp until you are over by Mun and right next to the perhaps is with Mun, then decelerate until you get an orbit. Adjust your orbit by burning retrograde as appropriate, into a reasonably circular orbit. Try to get the orbit so it crosses one of the large craters, they\'re pretty smooth to land in.

Next to get to the surface, the\'s lots of ways. I like to choose a spot, then wait until I\'m say 10-20 degrees short of being over the top of it, then decelerate hard until your orbit intersects Mun, and keep burning until your intersection is about where you want to go. Remember that it may move further as you brake when you descend depending on how much lateral movement you retain.

Now I often switch to the spacecraft view and warp until, say, 50K or so, burn to reduce speed to under, say, 50-60 m/s, then switch off and drop to say, 20, repeat, etc. you can have fewer longer burns, or if confident just one final burn, experiment ! At say 4-5 K up you want to be pretty much dropping vertically, I like to keep the speed down here to 50 max but there\'s no hard and fast rules, just be sure to have enough time to slow down or, kersplattle ! Lower the landing legs at, say, 4K, and guide it down. If you keep aimed at the green circle with the cross you will remove all lateral velocity but it is hard as your speed drops to below 5-6 m/s to stay stable, as above, work on it. You can use RCS if you have it, it isn\'t essential. At the end try to get to around 2 m/s for the last 20 metres, it\'s a judgement call and you\'ll get better as you practice

In my install the surface of Mun is at A minimum of around 720-750 metres, often around 850, and that\'s in the craters. Can be up to 2K outside or more, hard to be sure but watch the terrain change.

That\'s it, you should be down. Next crank up the throttle and exit if you have the fuel. Aim at one of the pink items on the trackball to get an equatorial orbit. Get into low Mun orbit, burn to accelerate backwards, exit Mun orbit then got to your Kerbin apoapsis and burn retrograde until your orbit intersect Kerbin. Go home.

Phew, that\'s much longer than I thought. Sorry admins if it is too long.

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General rule of translating to burn off horizontal velocity: Exactly the same as the controls for making your ship point in a different direction, but reversed (I and K are 'correct' but J and L are reversed, the exact opposite of WASD) and you can\'t roll. Is that really too complex for anyone?

And yeah, the engine does it faster, but you can translate while pointing in any direction.

True. I guess it\'s a matter of preference. I would rather save the weight on my landers, because they tend to be small and easily controlled. Obviously if you have a large lander and pick up any horizontal velocity when you\'re only several hundred meters above the surface, RCS will save your butt. Also, RCS is going to be a big player when docking arrives. Gonna be real hard to dock without RCS. ;D

-Ziff

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In my opinion, it\'s all about efficiency. A perfect design will fail if your trajectories are wasteful. But a marginal design can go far with proper maneuvering, like having the wind at your back. So, if you\'re willing to read and learn, your trips will be much more successful.

Four of my favorite threads deal with efficiency in various phases of a flight:

• Closette\'s 'Altitude Mini-challenge' (the Goddard Problem thread);

• Tarmenius\' 'Optimal Ascent' challenge (about Gravity Turns);

• Tarmenius\' 'Optimal Landing' challenge (results at the bottom of the first post);

• Tarmenius\' 'Optimal MOI' challenge (the best way to approach from MCC1).

It\'s a lot of reading, so I\'ve set the links to good posts in each thread. Once you put these concepts into practice, they are powerful. 8)

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