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Great! Sorry if I was harsh. Truth be told, mechjeb taught me how to gravity turn more efficiently.

He meant as in an 'eastward' or prograde orbit, where you\'re traveling towards a 90 degree heading all the time in your orbit. Retrograde or 'westward' orbits have you traveling towards 270 degrees. Which type of 45 degrees do you mean? Do you mean intervals on the horizon or 45 degrees towards space/ground. After you establish an orbit for your gravity turn, you never really need to point towards anything other than N/S/E/W (0, 180, 90, 270 respectively on the gyroscope), unless you\'re trying to move or shape an orbit that\'s gone wonky for one reason or another (usually due to bad or awkward rocket design that throws you off, or a bad trans-Munar burn). You never really need to use the in-between headings unless something goes wrong or you\'re adjusting your ascent/descent to a body.

So, using some of the advice here - monodirectional RCS, no SAS or ASAS, setting the same altitude in both fields - I ended up with an apoapsis of 103km and a periapsis of 23km. The target was 71km. The rocket had plenty of power and fuel, no loose stages, and any parts that might inferere removed. It was a manned satellite with Z02 tanks, Solar Power Generators and a small half-size fuel tank + quarter-size thruster, carried by seven full-size liquid fuel thrusters under 21 full-size liquid fuel tanks; six of the seven columns fed into the seventh and were discarded once the remaining fuel was down to three tanks. There were no observable abnormalities, but somehow the Gravity Turn phase keeps on ending up so very wrong. So, for the sake of experimentation, I just took one of those heavy jet cockpits, slapped a MechJeb unit, three tanks and a thruster onto it, put some SRBs below the whole cigar, and sent that thing up. 75km was the target. The resulting orbit was 74.8km on average, with 500m variations on apoapsis and periapsis. Inclination? Around 0,11 degrees. All of this prompted me to let loose a rather unfathomable curse. So what is it that makes the first rocket go back down like a homesick dog, while the little cigarillo (despite having its boosters explode from overheating) does the most accurate orbit I\'ve ever seen? PS: The smaller rocket even managed to do a perfect landing on its thruster without falling over. And there\'s 3/4 of the last tank left, too!

You can use MechJeb to get there automatically, and then analyze how it gets your rocket in orbit. But the basics are: - Climb vertically until 10-12km - Begin gravity turn (slowly) and try to get a pitch of 0° before 60km (the atmosphere is so thin at this altitude, that it isn\'t worth pitching up anymore, plus you still have vertical velocity from launch) - Burn heading East (for a 0° inclination) until your Apoapsis reaches 120 km, then let your rocket get there - Start burning shortly before reaching Ap to get your Pe to the same altitude E: Ninja\'d

... or, you could always download or mod yourself and do one little engine with enormous push. I mean Duck, honestly... doesn\'t it seem to you that these mods are beginning to defeat the purpose? How about a heavy lifter with default tanks/engines? So, to answer the OP: This is what i narrowed down my vehicles to, trying to keep a reasonable budget and only use the minimum needed: A stock parts munar heavy(ish) lifter would be a 3-stager with boosters as a 4th stage. As the worst part of the lift is the first couple of minutes, at the start you should fire 6 non-thrustvectoring engines with the force of 200 - those are boosters, they each have 3 tanks on top, control surfaces on sides (1 each) and will detach when they run dry. Also at the start fire the 3 thrustvectoring in the central column, which should have 3 tanks for each engine. Detach the boosters (should happen during the gravity turn), then the central column (3 tv engines and the tanks). The next stage is the same as previous central column - 3 tv engines, 9 tanks. This one will probably stay in an annoying orbit. Next stage is payload - with its own small engine and 3 tanks of fuel, rcs and 8 rcs blocks ( 4 top, 4 bottom), an asas and a mechjeb. I have to admit, I have not tried this design (hopefully today). What I do though, is use a slightly lighter version of this design for keostationary launches (which are about halfway to the Mun) with final stage of over 10 tons. I only use 1 tank on top of each booster (but as we all know it can hold up to 3 effectively), and only 2 tanks on the last stage. In my case that\'s enough, with an added advantage that the second stage also returns to Kerbin and does not litter my space : ) EDIT: Oops, looks like I described my previous design. Sorry. Skip the middle stage altogether, you shouldn\'t need it. Just 6 boosters, central column and payload ship on top of that. And if you do add the middle stage, this should be enough to launch a whole house up there. I\'ll give it a try soon : )

I suggest not making plane corrections mid-flight, but watch your navball at launch and point slightly (6°) below the 90° (East) mark you launch to the Mun with when you do your gravity turn. It is more fuel efficient and simpler.

Go to the map view and bring up the navball there so you can control the ship from the map. Then during launch, do your gravity turn normally but watch your apoapsis on the map view; cut your engine when apoapsis reaches the altitude you want. At that point, wait until you get to apoapsis and start your circularization burn facing prograde a few seconds before you reach it. If the apoapsis starts to run away from you, stop the burn, warp to catch up to apoapsis, and burn again. Repeat until the orbit is as circular as you desire. Remember to look at the map view religiously, it tells you everything you really need to know about your orbit.

Did you mean to say that the gravity turn is optimal only when there is an atmosphere?

Sounds to me like you\'re running out of fuel before you can reach your goals. That might be due to your craft design being too small for the trip, or it might be due to inefficiencies in your trajectory. (If you get the ascent speed and gravity turn optimized, that leaves a lot of fuel for the rest of your trip.) Check out those tutorial videos. Those are helpful to find other mistakes that might be slowing you down. I prefer Kosmo-not\'s guide.

When something I\'ve built refuses to stabilize but tumbles uncontrollably, it\'s usually because two parts are overlapped. If the thing doesn\'t explode immediately, it instead stretches and bounces around, resulting in massive torque forces. For example, I built a launcher for the cart mod, but didn\'t notice the wheels can move into some fuel tanks. This problem didn\'t show up until halfway through the gravity turn, when suddenly the wheels were bouncing around 100m on either side of the ship. (Not good for the cart suspension!) This movement made the ship tumble more and more until I ejected the colliding parts, but then it was ok. edit: On a second look at your ISS, I think I see some modules connected into a square formation. I\'m not sure if this is a problem in KSP, but some physics programs (i.e. Phun) will freak out over circular connections. Little oscillations repeat around the loop and slowly amplify without limit, causing things like wiggles, explosions, and perpetual motion machines: .

But getting there is half the fun! Thanks for taking a look. Yes, I just focused on the descent phase because it\'s easier to analyze, and for most people does not involve staging at this time so the mass stays ~ constant. Approaching directly or from an elliptical orbit - not covered, and if you\'re after a particular landing spot you\'ll need a gravity turn and some optimal control theory to get the most fuel-efficient approach. Speaking of which, here\'s an interesting demonstration of that (in 1-dimension, but still a tough problem) on the Mathematica site: http://demonstrations.wolfram.com/MoonLandingSimulation/ At least the equation above gives one a ballpark delta-v to land as a function of altitude, for those who choose to enter orbit first with their landing stage and look for a nice spot. Something which I rarely do myself, but now I know that lower is better if I can get there with my trans-munar stage first. Oh, and playing around briefly with the KSP Orbit Mechanic Java tool (settings: Mun, Hohmann transfer) I don\'t see a big difference in delta-v from a large initial orbit (300km altitude) to say a 5km vs a 10km altitude final orbit. Both add an additional ~ 200 m/s delta-v. Of course almost no-one enters the Mun\'s Sphere of Influence with a circular orbit but these figures are a rough guide.

Glad you found this thread, Kosmo, because the credit for data-taking and inspiration for this is all due to you. I think a scale height of 4850+/-150m is an acceptable result we can all agree on? You could get better drag data above 30 km by dropping the command module from way above the atmosphere - that way you\'ll be slamming into the upper layers much faster, which will increase the drag force and its effect on acceleration. But above 30 km no-one really cares, since most people have made their gravity turn by then and the terminal speed becomes comparable to the orbital speed up there. (In fact that is why one should be orienting the nose to build up orbital velocity and not so much to push through the atmosphere by then. We all knew it, but your data proves it!). I\'d like to see (and I\'m not asking you, although it would be a huge favor) similar data for something with larger mass total maximum_drag factor, e.g. a command pod + empty LFE. I\'m just not convinced that the maximum_drag factors are simply additive in the model as claimed elsewhere. If they were, then one would expect a greater difference in the falling speeds of big vs. small objects - with terminal speed proportional to sqrt(total drag factor) - which I am just not seeing in practice. Since objects fall faster than their terminal speeds in an exponential atmosphere the only way to measure the actual drag on them is by calculating their accelerations, as you did.

I\'ve been seeing a lot of videos lately where people are taking off and doing a gravity turn the opposite way I\'ve been normally doing them. Maybe I\'m under the wrong impression, but isn\'t the solid red line on the navball south? Isn\'t it easier to drop to the east rather than west?