ineon

Taxi back to the runway? It would take a bit longer, but you would do it.

Seems absolutely fine to me . I had considered different engines in lieu of control surfaces, but I went with attempting to control CoM instead.

Please feel free to do better - it is a challenge after all. And in the rules: so you don't need to land exactly on the runway

If you have done much plane building you will know that planes usually have 5 sets of control surfaces: 2 sets of ailerons, 2 elevators/canards and 1 rudder. It is possible to combine the elevators and ailerons into elevons, and so use 3 sets of control surfaces (2 elevons and 1 rudder). Your challenge today is to reduce that further. The challenge Design and fly a plane from the KSC runway to the island runway with as few control surfaces as possible. End your flight on the runway of the island and show the flight time. In addition to few control you must also not use gimbaling, RCS or reaction wheels as this would make the challenge far too easy (and not nearly explodey enough). Post pictures of the flight and landing. The challenge is split into 3 levels: Who needs yaw control anyway? level - using just 2 control surfaces Who's steering this thing? level - using only 1 control surface Asymmetric thrust master! level - using 0 control surfaces The winner of each section is the pilot with the fastest time. The rules You must have 0, 1 or 2 control surfaces on your plane (or vehicle - I assume that you will build a plane, but any other type is fine) Planes can be manned or automated You must actually fly - no driving to the water and then sailing there! Although you can taxi around You may include components that contain reaction wheels, but you must disable them (post a pic of them disabled) You may also include components that have gimbal, but again you must disable them (and post a pic) No cheaty cheating! (e.g. hyperedit, etc...) You must start off flying directly East (i.e. no pointing your plane directly the island and trying to get the right ballistic trajectory) Your plane must arrive in one piece Mods Infernal robotics + regular wings = control surfaces, so I am going to ban IR. No mods that change aerodynamics - let's keep this a level playing field No mods that add wing parts If mechjeb can fly your plane then well done to you - so go ahead I might disallow some more mods if they look too cheaty Who needs yaw control anyway? leader board Who's steering this things? leader board @ineon - 3:22 Asymmetric thrust master! leaderboard @funk - 3:10 @zolotiyeruki - 17:04 Notable mention to @Nich - first to get close to the the island runway without any control surfaces. My try Here is my submission demonstrating that it is actually possible. I am doing the Who's steering this thing? level with a single control surface on the tail providing some pitch. Roll is achieved by moving ore between 2 tanks on the wings. Time 3 minutes 22 seconds.

Wooo, I'm in space. Thanks everyone for your help. I think the problem was that the bottoms of the engines were clipping into each other. I did also remove the fins from the boosters and rotate the boosters around the centre tank by 45 degrees so that the main tank has fins on the N, S, E & W sides and the boosters were on NE, NW, SE & SW sides. I'm sure this didn't hurt. I did a small test with the slanted nose cones. It looks like the boosters do go in the direction that the nose points, but the force is so miniscule that it is nothing compared to sepratrons.

Hi EVA_Reentry, Good job, it is clear that you have put a lot of effort in. Can I offer some constructive criticism? You are nearly posting this in the right place. There is a sub-forum within the Questions and Tutorials section dedicated to just tutorials. Formatting: You spent a lot of effort on the content, so don't forget to spend a little effort on making the content look nice. Titles and subtitles (or bold, or underline, or ... but keep elegant) make it easier to find what you are looking for. To me, it was a little hard to read because it looked a little like a wall of text. A few small pictures might also be helpful too, e.g. "This is what the CoM marker looks like". I think you have focused on breadth over depth. To me, a really good tutorial to focuses on one specific detail rather than try to cram everything in. For example in the seaplane section you have just said "Struts!" and nothing more about them. Are they good or bad? How should I use them? These are good things to put into a tutorial (e.g. like you have done in the "What is gimbal?" section). There are hundreds of tutorials in the tutorials section (and elsewhere on the interwebs). How is yours going to stand out? I hope those are helpful bits of advice.

Wow everyone thanks for the feedback . I don't think I'll have a chance to try anything out until Tuesday, but I'll comment on some of what is above. Regarding decoupler placement, I think the decoupler is a far up as it can be. I have seen others suggest this as good advice and tried to generally follow it. But as @FancyMouse points out I've got 2 separatrons shop the decoupler force is minimal. What I didn't show in the imgur album is the one time that I got to space - when I staged the other set of engines at about 60km - the main thing that they did was spin rather than be pushed further out. Regarding placing them lower down and further out, I will definitely give that a go. Regarding nose cones, I changed to sloping because my intuition is that it should push them out - the nose cone pushes air into the middle and the (equal and opposite) reaction pushes the tank out. Is that not the case? And what is wrong with the intuition? I'll also try rotating them around. @rhomphaia which was did the rockets turn in you experiment - towards the direction that of the slope or away? Finally regarding the wings, it appears my intuition is at odds with the community here again. I would have thought that the CoM and Cod are both in the moved outwards by the tail (compared to just the tank on its own), but that the trail would move the drag more than the mass, and this would induce a rotation outwards. What am I missing? Thanks once again everyone.

Can I have some help with a spacecraft please? I would like it to not explode during launch. The Imgur album below is from me hammering the f1 key during doing the first staging. The tanks spin into the main body and things get a little explody. I don't know what the arrows all represent in the aero overlay, but I assume that the cyan arrows going inwards (from about image 3) from the staged tanks are the problems. Obviously I have tried attaching sepratrons which are not able to overcome the inward force (they do point the right way - just triple checked). I am using the nose-cone that slants outwards hoping that it would push the tanks out. It is also nothing to do with SAS, the rocket is (surprisingly) aerodynamically stable and the SAS is turned off. One thing that I noticed is that the one time I tried staging the other 2 tanks first, they still rolled inwards, but they did not destroy the rest of the ship and I was able to go to space that day. Although that might have been due to many other factors. I am not using any mods that affect the physics. p.s. Please pay no attention to the altitude, speed and angle and what that implies about my gravity turn

Not a direct answer to your question, but... I always set up a maneuver node when using Ion Engines and get MechJeb to execute it. Depending on how long the burn is, I might go off and do something else while it is going.

One important thing that I always try before sending a space plane to space is seeing how it acts as a plane. I will empty all the rocket fuel out (anything that contains LF&O) and and empty 90% of the remaining LF. At that point I want to simulate landing it from space to stop me wasting my time by orbiting something that will not re-enter. I'll try a couple of things: Does it turn? How slowly can it go without dropping out of the sky? Can I land it? And can I reliably point it at the runway? As many will tell you designing (and flying) a space plane is hard, and without a picture it might be hard to tell you exactly what is wrong. However, here are some general thoughts: Have you angled the attack of wings up by a few degrees? This gives the plane a small amount of natural lift. How far are the control surfaces from the centre of mass? If the dry CoM is near the front, then elevator (on the tail) will provide you with the best control. If it is at the back then canards (at the front) will give you better control. More wings!!! (although you might have already mentioned you tried this) Have you tried running your engines at 10-25% to give you a little more speed? Landing slowly is important, but the approach doesn't need to be so slow. You've not got airbrakes on have you? Probably obvious, but I thought that I would ask.

Hence my question. It is the gravity for Kerbin - why does it appear in the dV equation for when you are on Minmus (or anywhere else)?

The calculation is dv = ln(MStart / MEnd) * ISP * 9.81 But why is that 9.81 in there? I assume that it is the acceleration due to gravity on Kerbin and Earth (or it could just be a 1-in-100 coincidence). Is the calculation different on Jool (or Mars?) where the acceleration due to gravity is completely different? Is there a reason that the specific impulse isn't just quoted as 9.81 times higher and then we just drop the "* 9.81" from the equation?

Oh, I certainly hear ya on the OCD, brother. And if it's for aesthetic reasons, fine. Just wanted to make sure you knew that you don't have to for physics reasons. My interpretation is that the physicsless components are just a visual representation of something that you would just put inside the ship - probably the cockpit. In reality you would have a tiny port which is closed most of the time for a small thermometer sensor to pop out of. The rest of the thermometer (the bit that stores the measurement etc.) would be inside - i.e. real life clipped into the body. Something like the Gravoli sensor would not need for anything to reach outside. This allows my OCDness to put them on the outside of the craft.

There is an 'outstanding issue' that a craft does not check whether it collides with itself. I believe that this is the case for all parts. This can be especially annoying when you have just attached a sub-module on a wobbly docking port and attempt to launch it.

Ok, so that was probably a bit of an overstatement to say that absolutely everybody uses canards all the time, but it still got me wondering... I had never heard of canards before playing KSP. I might have seen a plane with canards IRL, but I don't recall it if I have. Most planes that I see do not have have them (although this might be a biased sample as the majority of planes are passenger airlines, and have a very specific purpose and therefore a very specific design). If I were to draw a 'typical' plane then it would have wings and a tail with elevators, and I might even be able to stretch to a delta-wing with elevons. I'm not saying that they don't exist IRL, but they are just a lot less common (to me) So why is it this way? Probably about 30% of atmoplanes and spaceplances I see on this forum have canards. (Why) are canards better for KSP than in real life? Or to turn the question around, why don't we see as many planes IRL with canards?

Another importantly overlooked one is time*. If you have time pressure on your Kerballing time (work, school, family, boy/girlfriend, ...) then having a highly time efficient launch/transfer/landing can mean more time for other contracts ( = more money). *Although not relevant in sandbox mode.

Were you in a very low orbit? It could be that by changing your direction by just a few m/s that you were changing from an orbital trajectory to a sub-orbital trajectory. I think that when you are orbiting then down is towards the south pole, whereas when you are sub-orbital down is towards the ground. Even if this is the case, then I agree that it still seems fairly poor usability to have all the directions flip.

I only ever reduce the gimbal if I am following the prograde, but the rocket is really shaking. No idea if it really helps, but it stops it shaking as much, and Scott Manley did it...

This is fairly common advise on the forum, but I'll say it anyway in case you have not seen it: what happens to the CoM marker if you start to empty out the fuel? Does it move nearer to the CoL? If it shifts about too much depending on fuel level then you could have a plane that flies fine one moment and then flips out the next when you burn some more fuel. Also be aware that the centre of lift and the centre of drag are not the same thing. CoD is what causes you to flip. Unfortunately CoD changes even more in flight, and there isn't a nice simple marker that you can apply in the SPH.

There might be one "perfect storm" scenario: I very occasionally find that a quicksave I load has a kerbal falling through the ground, or a ship mid explosion. When that happens I am glad that I have another save usually very recently. You might run into the situation where the game crashes and the persistent save is useless for some reason. But I think that is so unlikely that it is probably not worth bothering about.

Hmmm... If I am only doing crew rotations, then you are right, and I can get rid of all that drag from RCS thrusters. I completely forgot about that. Well remembered.

I am optimising a spaceplane that I successfully got to orbit, docked and de-orbited. It flies really nicely, has great manoeuvrability, can land really gently but could do with a bit of work getting it to dock nicely. It has 2 Mk1 Inline Cockpits, and I think that I want to change it for a Mk1 Crew Cabin. I am going to use it for crew rotations - no cargo. Detailed analysis if you really want it: The advantages that I see are that it does not require a pilot to be one of the crew that is rotating, as well as being marginally lighter and cheaper (20Kerbucks saved - woo) and the other specs are about the same. I could also use it for tourists too. Having a cargo bay has the small advantage that I can put other radially attached parts in there too to avoid drag (mechjeb is the main one). The big disadvantage is that if I loose power then I am completely dead in the water space, whereas if I had a command module I could at least manoeuvre using RCS or control surfaces, or fire the engine when I am pointing in approximately in the right direction. Another small disadvantage is that there are 3 things in the plane instead of 2, this makes it slightly longer and has more places for it going spaghetti on me (it does have enough lift to tear itself apart at mach3 under 10km altitude). I guess that I have a few more options in placing components wrt getting the CoM in the right place, but equally more complexity. Any more advantages or disadvantages that I have missed?

Correct, but... If I have 2 contracts: Put a satellite with a docking port, thermometer and can generate power in a 75kmx75km orbit Put a satellite with a docking port, goo canister and can generate power in a 80kmx80km orbit then I can launch a satellite with docking port, thermometer and goo canister into a 75km orbit and move it to fulfil the second contract provided I accepted both contracts before launch.

Posting screenshots: http://forum.kerbalspaceprogram.com/index.php?/topic/128907-how-do-you-post-pictures/#comment-2342176

You say that with a high degree of certainty. Can I ask how you are so sure?