pincushionman

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About pincushionman

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  1. pincushionman

    Please, PLEASE explain what Delta V is SIMPLY

    Now, @The_Cat_In_Space, we know you wanted a short, simple answer, but the reality, like everything else in rocket science, there's actually a lot going on. The previous posters have already given good descriptions of what it means in terms of describing what a rocket can do, but I'm going to go at it from the other direction - describing what your rocket is attempting to do. Orbits are paths of constant total energy within a gravity field. We know that energy is a function of mass and position (potential energy) or mass and velocity (kinetic energy). However, because the mass of an object doesn't change throughout an orbit, and because of how gravity works, the mass terms actually "fall out" of the orbital math and we're left with position and velocity being the only important variables. When we describe orbits in KSP, we usually use orbial elements to do that job, since they're easier to digest. But an orbit is equally a set of positions and the velocity vectors at each point. And we don't need the whole set - it is sufficient to use only a single location and the associated velocity vector to uniquely describe an orbit. KSP, in fact, does have to use this formulation - in order to do patched conics, you find your xyz position and xyz velocity vectors at the SOI boundary, transform them into the new reference frame, and then derive the new orbital elements from that information. And if you're doing N-body physics, you don't have true orbits, you only have position and velocity. All right, this is getting long, but stay with me here. So when we compare two different orbits, we need to compare both the position vector and the velocity vector for each. However, when we're trying to describe a maneuver, we're not describing any two old orbits - we're describing intersecting ones. We're moving from one orbit to another where the position is the same in each orbit. Since the positions are the same, the only difference between the orbits is their respective velocity vectors. And the math you need to do those comparisons isn't calculus, you only need arithmetic. In terms of describing these maneuvers, delta-V (change in velocity) is exactly that - the vector difference between the two velocity vectors. Note that I didn't say speed, but I emphasized vector and velocity, because that's important. Most maneuvers are of the increase/decrease speed variety, but if you've ever done a pure plane change, you'll notice your starting and ending speeds are the same. The velocity change is due entirely to direction change. We normally assume that pointing your vessel in the correct direction is a free action. And to make things more confusing, this has absolutely nothing to do with the fact that you'll be moving at different speeds at different times during an orbit (fast at periapsis, slow at apoapsis). That's a whole different thing. So the delta-V of a manuever is the cost of doing that maneuver - how much do I need to be able to change my speed and direction to get to that new path. The delta-V of your rocket (described by the other posters) is a measure of how-much-maneuver-can-my-rocket-do-before-I'm-out-of-gas.
  2. pincushionman

    Monoprop Oberth Assist: Good idea?

    If you already have the monoprop onboard AND you have enough time to make your burns AND you make sure you retain enough for your other maneuvering needs, there is no downside to it. Un-burned…un-shot…un-disassociated? Un-used monopropellant is dead weight. A mixed LFO/MP burn is less efficient than an LFO-only burn of the same tonnage of fuel. However, you’ll have two things going in your favor. First, you will shed more mass during the burn, so all subsequent burns will be more efficient. Second, you’ll have more thrust, so the maneuver will take less time, meaning you’re closer to the theoretical instant maneuver and you’ll lose less to cosine loses. Of course, the efficiency thing is most true if the monoprop is used first, while the thrust part is only true if you burn both fuels sumultaneously. How much will it help? That we can’t tell unless you give us more info on your craft. You’re transporting a load of fuel, which is a heavy payload. Unless you way over-budgeted your MP, I’m guessing your MP is actually a small fraction of your mass, so the actual efficiency gain will be minimal. Likewise, unless your LFO engines are small (less than, say, 200 kN of thrust), the extra thrust isn’t going to be all that helpful, either. But you’ve already got it there, so you might as well use it. If, on the other hand, you haven’t launched yet, you’d be better off putting in a smaller MP tank to begin with.
  3. pincushionman

    Accelating a Planet

    Not exaclty the question, but Kurde…Kiuzedg…Kurzgemahhozit…these guys touched on the “would it change the Earth’s orbit” question in this video. Didn’t go into any of the details the preceding posters touched on, though.
  4. pincushionman

    Construction Grouping

    Regardless of whether you use merge, subassembly, or build in situ, you may need to re-think how your wings are built. Attaching wing sections to the fuselage ahead of/behind existing wing parts will continue to make “strips” of wing parts like you do now. If, however, you choose one wing part to be the “wing root”, so to speak, you can build a whole wing like a tree branch, adding more wing parts to existing ones (which may mean parts are put on “sideways”), able to pick it up and move it as a unit as long as you remember which root part to grab. This will, however, change the distribution of forces within the wing. Instead of a number of wing strips each cantilevered off the fuselage, you’ll now have the entire wing force being beamed through the network of wing parts back to the root, which may introduce deflections and moments that are significantly different than what you’re used to. In the past, this has required (for large wings) extensive use of struts to re-distribute the forces back to the fuselage components along the entire chord. Someone with better recent plane-building experience will need to weigh in on how autostrut and rigid connection change things (that is, I could be full of … from being out of the plane-building game).
  5. pincushionman

    How to see Kerbals through windows on Console

    Are you talking about the interior views from the Kerbals’ perspectives, or are you talking about seeing into the pods from the outside?
  6. pincushionman

    How to set up fire alarm panel

    Before dismissing the thought of professionally-installed or -monitored systems, check with your insurance. Not only is it their business to be able to make reccomendations on such things, it may result in a reduction in premiums, especially if this would fall under an existing business/farm policy.
  7. pincushionman

    R&D Building Biomes bug?

    There is a map on Reddit of the minibiomes, but it only shows the locations on the fully-upgraded KSC…and certain biomes are available at certain levels. Does anyone know of a better set of maps that has all upgrade levels?
  8. pincushionman

    Unity Analytics and the GDPR

    There used to be a popup about that. But it’s been so long since I’ve seen it I don’t remember what it was or exactly what kind of data it was asking about.
  9. pincushionman

    Plane keeps veering

    Are you in the VAB? Because something is not right with the aero center - and that could be hiding additional problems.
  10. pincushionman

    Steam Summer Sale 2018

    I’m looking at Shovel Knight and Hollow Knight, myself. I would consider Making History as well…but I’m waiting for the whole GPDR/analytics/Red Shell thing to be addressed first.
  11. pincushionman

    Mun slingshots.

    The reason most people don’t do it is threefold (and the first two…folds have been mentioned already): 1) The precision needed to use it effectively makes it difficult for most players. 2) The ammount of dV saved is marginal compared to said effort, with the exception of Jool-system gravity braking. Jool assists would be more useful (as we use Jupiter in real life), except there aren’t any more outer planets to go to using it. 3) Most importantly, it’s astonishingly easy to over-dV your ships in KSP, and outside of self-imposed low-dV challenges, there’s little incentive to do otherwise.
  12. pincushionman

    Theories on Mystery Goo?

    It’s not entirely clear, but while the exposed kraken is seen entering a Science Jr., the “hazardous material” may in fact be Goo.
  13. It’s not possible to use that information outside of data-mining the game state. But if there were an option to have the celestial axes drawn on the focused body - or better yet, a grid - the data would immediately become relevant and useful.
  14. Not sure what you’re trying to accomplish with the MIRV configuration, but if it’s “get multiple Kerbals to space and back simultaneously for level-up/contracts” you’d be better off keeping all three pods connected. Or better yet, use one command pod and a crew cabin. Only one craft, so no physics-range problems - note that if you do a more-horizontal flight as suggested, your draggier capsules will go out of range and be destroyed. I myself use such a craft in my save.
  15. pincushionman

    Symmetric placement not really symmetric?

    Slightly unsymmetric stiffness has been a longstanding bug in the game. The two wings deform differently under load (twist and bend), causing the difference in lift and a roll (usually to the left in my experience, but that’s not a certain thing). It’s also the source of the imfamous “why does my plane veer to the left on the runway?” behavior. Stiffer structure (struts, autostrut, KJR) helps, but you can’t get rid of it completely.