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    Sr. Spacecraft Engineer
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    Orbiting... something. Bill, are the scanners working yet?

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  1. The docking port and claw attachment off the center of spin (assuming the blue arms are the traveling arms) will slightly offset Center of Mass because it's not matched on the other side. With CoM slightly off, and SAS not countering, you will get imbalance eventually, particularly with a good sized fuel tank there. To add additional minor influences, on another axis there's something hanging off the large engine's gas tank that looks like a tiny cylinder of something with a docking port on the end. KSP and rounding errors being what they are, if you're not perfect, don't spin.
  2. There's a couple of indicators you can use as you take off. First, if you've got the default skybox, there's a band of stars about level with the orbital plane. Use that as a guide for equatorial aim for prograde/retrograde. Also, you want to turn the camera so Minmus is just barely on screen, use spacebar to orient that way, then thrust forward. It's not exact but it gets you close to pro/retro. For the above, thrusting prograde basically means get a bit off the ground and then run horizontal with most of your propellant to achieve orbit with just your EVA pack. From there, you figure out your rendezvous. Don't try to rendezvous directly from ground, you'll want to do it from orbit, like any other rendezvous, just with a lot less clutter like SAS, thrust controls, etc... XD It's totally doable, but a direct intercept with your ship in orbit means that you go straight up to try to catch it, then suddenly you have to get ~180 m/s sideways speed. It's much, much easier to achieve orbit and then rendezvous.
  3. Rounding errors, offset CoM, part #'s, clipping being erratic... Lots of stuff. Pics please. Also, side note, once it goes 'on rails' when you switch away from it, the spinning will stop. Also if you time warp.
  4. This guy needs his own research center somewhere FAR FAR away. Perhaps on a low solar orbit without notification that it's a decaying one! That's just in case his experiments reach sentience or grey goo status or something. Need to be careful.
  5. It's a bugfix for some really odd things happening to orbits that was brought into play in 1.1.3. I've yet to see a solid answer to why it's toggleable other than a 'lack of hubris on the part of the devs', in case it created other problems. There's no real decay in KSP, everything's on rails when you're not driving it.
  6. So, the question is answered, but I'd like to add a note. Traveling to Minmus and the *ahem* Butterfly dribble effect is something that will heavily influence any interplanetary transfers you'll do. Mun's great as a first target. Minmus actually teaches the little bits and pieces that end up getting exponentially multiplied for interplanetary transfers. That last 10 dV is murder!
  7. Is there a good link you know of for an introduction to vis-viva equation? I've never heard the term before and would like to get acquainted.
  8. Drag from shape, convenience of a big round cylinder to stick things to with not much other purpose, fits the 2.5m rockets nicely.
  9. As of KSP 1.2.2, epic bases are not gone: This was entirely built with landing legs and a rover moving parts around and connecting them up. I have no float or kraken issues with it, but I also have no autostrutting going on.
  10. There are pros to bringing along multiple copies of the same experiment, even on a simple flyby (but only two). If you don't have a scientist on board who can grab the data and reset the experiment (Materials Bay and Goo) bringing along one for both high and low space flight can let you get a larger science recovery then doing both in the same biome. For example, the Goo Bay gets 10 units of science per experiment (leaving out biome multipliers here). Maximum value per biome is 13. Transmission efficiency is 30%. So, to expand on what Bewing said above, transmitting 30% of 10 (3 units) and then resetting the experiment with a scientist and recovering it will max out that biome in a single pass, bringing you up to 13 units. Mat Bay is similar. However, if you don't have a scientist to reset the experiment, you'll need two goos to get the full 13 units of science from the biome. Better, though, would be to use those two goos to get 10 from high, and 10 from low, and get 20 total science from the trip, instead of 13. To get full science without a scientist to reset, you'd need 4 goo canisters, 2 for each biome, for a total of 26. Usually not worth the weight.
  11. What about sticking the claw onto the carrier deck, then piloting the plane over to the claw, then lowering the landing gear on the plane to get the armed claw to grab it? No random parts on your plane, and your aircraft carrier will now look like a giant space monster if you arm them all at once!
  12. I typically put my apo on the correct orbit, periapsis as low as possible, then guesstimate with KAC when I should come back and care for circularization.
  13. TWR increases as you burn fuel and lower weight. Think of it as if you tossed a fuel tank overboard... your TWR is already better even if you're not going as far. dV isn't actually a function of thrust over time, momentum change is. dV is a measure of how much you can change overall, I misspoke above, apologies, I got caught up in the TWR vs. dV discussion in my head. Most likely the time is based on burn times, but what burn time I can't tell you (full burn, current throttle, all stages, etc), as I don't use MJ. The part that truly matters for burn time is early in your 'weight' you'll need to burn longer to achieve some amount of dV instead of later, when you're lighter and your TWR is improved.
  14. I can't speak to MechJeb, but I can help you out with Delta-V (dV for short). First off, the equations and the like I'll be referencing can most easily be found here, though there are plenty of others if you google ksp delta v calculation: http://wiki.kerbalspaceprogram.com/wiki/Tutorial:Advanced_Rocket_Design dV is a function of thrust over time. It's a Delta to your velocity (or vector, depending on thought), thus V. This isn't directly equated to a burn time, as you can burn at different rates for less, or more, change per second. However, there is a max-throttle burn time and/or a at current throttle burn time, which is the time number you're seeing above. Which one it is in MJ, I'm not sure. Now, dV is calculated by your wet mass, your dry mass, and the ISP (think gas milage when starting to ease your mind around the idea) of the engine(s) involved, using the gravity of the world the ISP was rated on as a constant to determine Exhaust Velocity. It's a log equation also known as Tsiolkovsky equation to figure out how much vector you can change on your current ship as a factor of the fuel you'll burn going from wet (heaviest, worst mpg) to dry (lightest, best mpg). For our purposes, it's a plug and play function, we just need a calculator. Divide the wet mass of your ship by the dry mass (Example: 10t craft with 6t of fuel), so 10/6. Use the ln function (Natural Log) on your calculator against the result of that. Then multiply it by the ISP listed in game (we'll use 320 for the vacuum ISP for the moment) and then by 9.81, the gravity constant of where the ISP was rated from. So, 10/6 =~ 1.667. ln(1.667) = .5108. * 320 * 9.81 = 1603.58. So, roughly 1,603.58 m/s of dV. This means you can adjust your velocity by that much with that fuel and engine. So if you had an orbital speed of around 1,603 m/s, you could burn off all your fuel and fall like a brick, or use a little over half of that to transfer burn to Mun (which costs ~850). Finally, the # that's getting you during your circularization burn (achieving apoapsis and raising periapsis to NOT fall back into the atmosphere) is the TWR, or Thrust to Weight Ratio. This is done via the kN (KiloNeutons) rating on the engines you're burning. Typically a 6,000+ dV is done with Nukes, and these are notorious for not having TWR worthy of fast maneuvers. They're almost specifically used once in orbit and often over multiple burns at periapsis to get your apoapsis to the required height. The math for TWR is also relatively simple once you have all the #'s to plug into the equation, and that DOES change as you burn fuel, you'll have a higher TWR the lighter the craft overall is. I suggest you check out this wiki page for more information on understanding TWR: http://wiki.kerbalspaceprogram.com/wiki/Thrust-to-weight_ratio
  15. 50-100k for a first stage? What are you launching?! That's... expensive. Like, huge space station expensive.
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