Jason Patterson

Something that will help maximize your final velocity is trying to impact a mountaintop rather than at sea level. There aren't any truly enormous mountains on Kerbin, but even an extra kilometer or two of altitude will decrease drag significantly.

If you burn straight upward then you are fighting the force of gravity the entire time - your engine's thrust is being opposed by it and a fraction is simply canceled out. By burning horizontally you can add velocity without fighting gravity at all. On Kerbin you have to get above the atmosphere, so you can't simply burn horizontally straight off of the launch pad, but on the Mun (or other small bodies with no atmosphere) this sort of approach is viable. Check out gravity drag for more information. The most efficient escape profile is to make a gravity turn exactly as you would when getting to orbit, but keep burning until you have escaped. If you need to escape in a particular direction (very likely) then a very slightly less efficient method is to launch into a low altitude orbit (70-80km) and then finish your escape from that orbit. With a good ascent profile this is only a bit less efficient than a direct ascent, and it is far easier to get right.

The delta-v for a given amount of fuel being moved by a particular number and set of engines is going to be a constant. If you were to install 4 LV-N's in the pattern that sal_vager showed, and provided them with the same amount of fuel as 4 LV-N's installed on 4 separate (smaller) tanks, it would go just as much. Perhaps you meant that 4 LV-N's vs 1 LV-N would get less delta-v from a given amount of fuel. In that case you would be correct, but not for the reason that you list. The only reason that it would get less delta-v is that it would have more non-fuel mass. Burning the fuel faster (or through four engines, however you want to think about it) would have no effect. The same amount of fuel mass will be expended at the same relative velocity in either case, so the same change in momentum (and thereby change in velocity) will occur. There are only three things that determine delta-v - fuel mass, non-fuel mass, and Isp of the engine(s). You'll have a much easier time steering your ships with two sets of RCS blocks, one set fore and one aft.

As Eric S said, it's rotPower that is involved in controlled turning of a vehicle. SAS only stops rotation, it does not (and cannot) help start rotation. Your probe module is the reason your turning is slow. You can increase turning power by adding additional probe modules (or an empty crew module) to the vessel, or use physics warp (alt-.) or wait patiently for the existing setup to do its job. It really shouldn't be terribly slow, even with the kind of mass you've got. SAS - When activated it works to stop rotation by applying a countertorque to the ship. ASAS - Uses any and all ship's systems (vectored engines, control surfaces, command module torque) to maintain a fixed attitude. It will return the ship to that attitude if the ship turns away. If it is used on a vessel without any system capable of causing a torque (don't know how that would be possible, but let's pretend) then it will do absolutely nothing. Avionics - Identical to ASAS except that instead of a fixed attitude, avionics works to maintain the vessel's current attitude. If it is perturbed from that to a new orientation, avionics will maintain the new orientation.

As my darling wife says when we're stuck behind someone going half the speed limit, "C'mon! It's the tall pedal!" Glad you got it sorted out.

Nah, the ports on the fuel tank are fine. Is there a strut stuck to the face of the coupling? If not, I would guess that it's a matter of junk on the sides of the fuel tanks bumping together to keep the faces from connecting properly. You've got a lot of rcs blocks and lights and stuff in the area. You can try to put the docking port on a truss in order to have it project away from the side of the tank. If you do this, do not use a cubic octagonal or octagonal strut. They're non-physics parts and when they're connected to docking ports, they'll cause all sorts of mayhem at docking (like tearing-your-entire-station-apart level mayhem.) Just to be sure, when the two faces are touching, they are doing so such that the faces are parallel to one another and their positions are lined up as well (in the same orientation that they will be when they finally do mate, that is)? When you're docking bulky items, that's far more important than when you dock something smaller. It's possible, if unlikely, that you've found a bug. I don't think we've had anyone posting about docking problems specific to this part that didn't wind up being a size mismatch, an obstructed docking port, or a technique issue.

Nope, the best you can do is pick them up and replace them, rotationally as sal suggested and their positions by zooming very close in.

If you're burning continuously to get to LKO, particularly if you're burning below the horizon, then you're expending extra fuel. Of course there will be a balance where this approach beats a too steep launch, but if you're burning downward at any point in the launch, then you're canceling out delta-v that you spent in order to get up to that altitude in the first place. With a clean gravity turn you should be able to hit a reasonable LKO apoapsis at 90% or more of the velocity you need in order to circularize at that altitude, and most of the time I make it into space with a periapsis. If that's not the case, then you should try making your turn earlier or more abruptly (which will also reduce your gravity drag.) Again, the exact balance between the two approaches depends entirely on the specifics of the launch, but generally speaking it's better to coast along a fairly flat trajectory rather than burning up too much early and then burning down to correct it later.

Fuel tanks (and other more or less passive parts) haven't been shown in staging since 0.16. If that is your concern, you can add drop tanks back into staging using a modified part that I wrote called the Drop Tank Fuel Gauge. If instead you're saying that fuel tanks just aren't functioning, and that you don't care whether they show up in staging, then you can try my impromptu trouble shooting decision tree for engines. (I just know that by the time I get this whole silly mess written out there will be a person saying, "Press spacebar," and that will solve the problem. I'm also fully anticipating a messed up decision tree... ) 1. Do you have an actual fuel tank installed on your vehicle (a part with a tool tip that includes liquidfuel)? If so, go to 2. Otherwise go to 6. 2. Are you using a rocket engine? If so, go to 3, otherwise go to 4. 3. Did you install a fuel tank with both liquid fuel and oxidizer? Check the tooltip to find out. If so, go to 7. If not, go to 6. 4. Do you have air intakes on your vehicle? If so, go to 7, if not, go to 5. 5. Install air intakes on your ship. 6. Install the correct fuel tank immediately adjacent to your engine in the VAB. 7. Launch your ship. 8. Check your staging. Is there an engine in the last (highest numbered) stage? If not go to 9, otherwise, go to 10. 9. Your staging is out of order. You need to drag and drop items in the staging bar in the VAB to rearrange things so that your first engines (and launch clamps, if you're using them) are in the last stage. 10. Press spacebar. If the engine does not activate (turn green with a fuel bar, empty or otherwise) go to 11, otherwise go to 16. 11. Is your rocket resting on the engine? If so, go to 12, otherwise, go to 13. 12. The weight of the rocket has broken off your engine. Try using launch stabilizers (structural tab) to hold the rocket above the launch pad. 13. Is your vessel functional in any other way? If not, go to 14, otherwise go to 30. 14. Is your vehicle controlled by a probe and it has lost power, or is it crewed and you removed the crew member from the command module? If so, go to 15, otherwise go to 30. 15. You need to supply power to a probe command module or have a crewed command module on a vessel in order to control it. 16. Does the engine show a full fuel bar? If so, go to 17, otherwise, go to 21. 17. Press the left shift key to increase your throttle. Does the engine activate (make noise/smoke even if the rocket doesn't go up)? If so, go to 18, otherwise go to 21. 18. Does the ship go up? If not, go to 19. 19. You may have too small an engine, or perhaps the wrong engine is activating in staging, or perhaps there is a part obstructing the engine's output. 20. Right click on the engine that you think should be active at this point. Is there a button that says Shutdown (or something similar)? If not, go to 9, otherwise go to 19. 21. Is the rocket resting on the engine? If so, go to 12, otherwise go to 22. 22. Is there a fuel tank directly connected to the engine? If not, go to 23, otherwise go to 30. 23. Is there a fuel line connection between the fuel tank and the engine? If so, go to 24, otherwise go to 27. 24. Is the fuel line actually attached to the fuel tank at one end and the engine at the other? If not, go to 25, otherwise go to 26. 25. Install the fuel line correctly in the VAB. Its ends much touch both the fuel tank and the engine, starting with the fuel tank and ending at the engine. 26. Is your fuel line backward? If so, go to 25, otherwise go to 30. 27. Is there a fuel crossflow part connecting the fuel tank to the engine? If so, go to 28, if not go to 29. 28. Fuel crossflow parts can be unpredictable in their behavior, particularly if you have multiple fuel crossflow parts connected to one another. There isn't a lot you can do to direct the fuel through them properly, but you can try installing a fuel line to cross the fuel tank/engine gap. Try posting a picture and/or craft file for further advice. 29. You either have a problem that goes beyond the scope of this troubleshooting tree or you missed a step. Retry it if you're feeling patient, otherwise go to 30. 30. That's really weird. You could try rebuilding the ship and see if that helps. Post a picture and/or craft file on here for further advice. You may have found a bug in the game. ETA: Fixed a numbering mistake and added some material to check for fuel tank inconsistencies. Feel free to let me know how it is broken at this point...

You might have better luck posting a picture of the craft and/or the craft file itself. It's hard to give general advice about specific problems.

At 30km, you generally want to be going substantially faster than 1200-1500 m/s. If you're limited to that speed at 30km, then I would suggest trying to cut some mass, which will also help your maneuverability. At that altitude you're barely in the atmosphere anymore, so your control surfaces won't work very well. Vectoring engines are helpful, but really, control pod torque should be enough to change the attitude of your plane. Are you turning off avionics at that point? If not, you should try doing so, since it will dampen any changes you try to make. Is your rocket engine(s) off axis vertically? If the thrust vector for the rockets doesn't go through the center of mass, then it's going to cause a torque toward the opposite side, which might be what's keeping you from going up.

Not even a little. It was expensive, scope limiting, and expensive. Good riddance. ETA: By scope limiting, I mean that during the entirety of the Shuttle program, the US was satisfied with never sending people much more than 100 miles up because we had people in space pretty much constantly, scraping the top of the atmosphere.

Getting to Duna takes about 75 days, then you'll have to wait for (I can't remember how long) for the launch window to get back. The return trip takes another 74 days. These are for Hohmann transfers, but if you want to use more delta-v, you can shorten the time significantly.

Yeah, it's more of a problem with getting a Moho or Dres encounter. It's a reasonably good approach for shrinking a close approach, in any case, particularly with maneuverable ships.

This. If you find that the maneuver node widget controls aren't sensitive enough (so that making any adjustment just messes things up more) then you can try test burns to figure out what you need to do to fix things. You're probably less than 100 m/s off course right now, so a small change can put you right in no time. To do this: 1. Turn your ship to face east (90 degrees, 0 pitch) and make the gentlest burn you can. If your separation with Duna increases, stop and face west instead (270 degrees, 0 pitch.) Make a very gentle burn until the separation distance stops shrinking. 2. Repeat the same process with north (0 degrees, 0 pitch) and/or south (180 degrees, 0 pitch.) 3. Repeat the same process with up (90 degrees pitch) and down (-90 pitch.) 4. Go back to step 1 and repeat as needed. This process is not the most efficient way to do it, but it works, and with a small burn like this, it's not going to waste much fuel over a single burn.

Indeed, struts work just fine. Similarly, you can place a pair of docking clamps so that their attachment faces are in the correct position to dock and they will connect as soon as the vessel loads. It requires some careful positioning, but it's not too hard to get right.

Not so much. From the highest altitudes it's not substantially less than 8000 m/s to orbit. From sea level it's something like 11,000 m/s. Eve is awful.

A return trip from Duna is the lowest delta-v interplanetary mission you can do; it's a great place to start. The biggest challenge for most KSP players is getting the idea that minimal designs are almost always best, and that's the case here. If you've built a ship that can get to Duna, you've almost surely got one that can get back home. Things to keep in mind: - Every kilo you can shave off of upper stages winds up saving 7-10 times more mass from the stage below (and that total mass saved saves another 7-10 times as much from lower stages and so on.) So keep your return stage as minimal as humanly possible if you're having trouble getting your vehicle into orbit. If you're reasonably good at launches and getting from place to place in the solar system, then you can get from Duna's surface to Kerbin's with a vehicle that masses 4 tons. (Command Pod Mk1 - parachute - ASAS module - FL-T400 fuel tank - LV-909 engine - ladder - LT-2 landing struts x 3. Go with LT-1 legs if you are good with landings, but the difference is small for the additional ruggedness that LT-2 gives.) Add an interplanetary transfer stage to this by attaching a pair of FL-T400 fuel tanks on radial decouplers with fuel lines. Done cleanly, you'd have ~1500m/s to get to Duna, ~900 m/s for slowing down at Duna (to assist your parachute and keep it from ripping off), ~1300 m/s to get back into orbit around Duna, and ~1300 m/s to get back to Kerbin. There is slop in all of this, and if you aerobrake properly at Duna, you could move the 900 m/s to any other part of the deal. Total mass for a vehicle to get from LKO to Duna's surface and back - 8.6 tons. I'm reasonably sure that you can get that into orbit. (This could definitely be shaved down further, for all of the minimalists who are thinking, "Oh yeah, well I did it in 4 tons!" This is a reasonable design with a fair amount of excess delta-v.) Note: If you want to add some wiggle room to the mission, change the fuel tank for the return vehicle to an FL-T800. That will add a couple of tons to the vehicle, but it also gives you another 600 m/s to play with. If you do this, you could also use an X200-8 fuel tank, which will give the same fuel load with a broader base, but it will look weird. - Good staging adds small but significant amounts of delta-v to virtually any design. If you aren't using asparagus staging, you should seriously consider doing so. Some people don't like the look and refuse to do it, but it's impossible to beat in the current version of the game. - Because Duna's atmosphere is thin, you want to try to land at the lowest altitude possible to maximize drag on your landing. Even with that, your landing can be pretty hairy. Be sure to add struts from your command module to the parachute, because it's going to deploy when you're going 400 m/s or faster, most likely. Also add struts from the command module to the ASAS and between the fuel tank and ASAS, because they really like to break at that point. I like the large, dark brown feature that crosses the equator for a landing site. It's flat and at the datum altitude, so landings are relatively easy. - Duna's atmosphere is so thin that your launch profile will be closer to launching from a vacuum planet than from Kerbin. You can start turning immediately, and go completely horizontal by the time you get to 5-10km. This will save you a substantial amount of delta-v from gravity drag. ETA: I forgot to mention that you will want to set up your parachute to activate via an action group. You can deploy it the first time using staging, but the second time, once you've repacked it at Duna, can't be done in staging, so you need the action group or you're going to make a hole in the ground on your return (though a powered landing on returning to Kerbin is a real possibility, believe it or not.) ETA some more: Another possibility is switching to an LV-N engine for the lander. I don't think it's a great choice here, however, since it will require you to build out the landing legs and add an additional ladder, plus the engine itself is much more massive than the LV-909. Swapping the engines out and making necessary changes to the landing gear and such got me something like 1000 m/s extra delta-v but it requires about 3 tons more mass and looks clunky. For a longer range trip, like a Moho or Dres return vehicle, it would be a much more viable option.

How is the ship getting to the point of not being right side up? Ideally you want to come in sideways with a low periapsis. That allows the little atmosphere that Duna has to slow you down as much as it can. Your velocity will become more vertical as the atmosphere slows you and gravity's downward pull dominates. Follow the retrograde velocity marker on your navball and deploy your chutes or fire your rockets to continue slowing as you approach the ground. You'll finish on a vertical descent (pointed upward, that is) and you can engage ASAS to lock in that orientation as you land. You often need small amounts of off axis thrust to correct for mistakes in your vessel's alignment, but you shouldn't need to get more than 5-10 degrees off of vertical once you're on that last part of the descent. If you have a large vessel with a small command module (or worse, a large vessel with a probe module) then the gyros in the command module might be too weak to rotate your ship quickly. It's also possible that you've got something wrong in your design that is causing the ship to be flipped over - it's hard telling without pictures and/or a .craft file. One common problem is that parachutes mounted below the vessel's center of mass can cause it to flip over when they deploy, and except for very small vehicles it's nearly impossible to recover to an upright orientation.

If you're playing the Steam version of the game, you'll upgrade through Steam when the next update becomes available. The patcher never really worked properly, so it was discontinued, and non-Steam accounts upgrade through the KSP Store (Log in, profile, scroll all the way to the bottom for download links.) There is a new patcher in the works, and of course the devs are working on 0.20, but there hasn't been a lot of visible progress due to various craziness. Hopefully we'll get some eye candy with the Tuesday update. Also no, I don't have problems with rockets lagging at any particular altitude.

Every stock part is buoyant by default. The way that water works currently is that parts are tested for collisions with the surface of the water only when they pass through it. Any part completely above or below the water's surface will survive even at high speed, and parts that are partially submerged can also survive, as long as they stay partially submerged (never sink entirely or emerge entirely.) The easiest parts to use for floats are wings, turned so that the long edge is parallel to the water. As far as flipping, it works exactly as you would expect. A broad, long base for your boat will result in a more stable design.

Not the curse of the unnecessary K's! Nooooooo! What's wrong with calling it a synchronous orbit and avoiding all of the alphabet soup excessive use of K foolishness?

Also, ouch. I realize that it doesn't actually matter, but my post count just went from well over 1,000 down to ~50, and all of my rep is gone. :-( I am no longer on a distinguished road.

My account is still here, but even though I have way more than 5 posts on the forum (according to a search) my posts are still being approved by moderators. Gotta love technology. My sympathies to whoever reads this and has to click OK before going on to the next one in line.

Has this been going on for some time, or is it a recent problem? Spaceport got bogged down/reset as well.