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Everything posted by Stochasty

  1. Finally got a halfway decent spaceplane into orbit. Here's a few trips: First trip, a simple test flight to orbit and back: http://imgur.com/a/yXHb6 Next trip, a quick pitstop on Minmus: http://imgur.com/a/uRJke Next up, the Mun! http://imgur.com/a/TYpch And finally, Duna http://imgur.com/a/IL86u Barely. Needed an 8 m/s burn on the trip home to drop periapsis into the atmosphere... and I almost didn't have enough. Less than 3 m/s left in the tank at the end.
  2. Dead? What nonsense is this? Not even close to dead; just not easy as pie anymore.
  3. Decided to start playing again now that 1.0 is out, and... wow! Changes! Looks like spaceplanes are hard again. The design I took to Moho won't even make orbit. Airhogging seems to be out as well; adding intakes reduces top speed, due to increased drag. The new jet engine thrust profile is going to take some getting used to; haven't managed to get a craft above 1300 m/s on airbreathers yet.
  4. Nose up posture on the runway + single front gear = wheelbarrow. What's happening is that, as you gain speed, your rear landing gear are lifting off of the ground, leaving your plane balanced on the single front gear. Not good. The solution is to change your posture to be either level or slightly nose down on the runway.
  5. The smallest positive integer greater than any finite number that can be represented using a computable algorithm with fewer than ten thousand symbols.
  6. What you are missing from a theoretical standpoint is that both metaphor's Moho voyage and the MESSENGER mission were using gravity assists in combination with deep space maneuvers. This is a case that I didn't cover in my tutorial (I was more interested in looking at what could be done from a pure gravity assist standpoint). Basically, the way these missions work is like this: suppose I'm in an orbit, where Moho marks my periapsis. I can use a flyby of Moho to drop my periapsis to inside Moho's orbit (simultaneously lowering my apoapsis). Then, on the next orbit, I can make a deep space maneuver at apoapsis to raise my periapsis back up to the level of Moho's orbit. By doing so, I will have lowered my effective closing velocity at my next Moho encounter by more (often much more) than the delta-V I spent during the deep space maneuver. With precision and timing, you can set things up so that, at each stage of this process, you end up in a resonant orbit and repeatedly encounter your target, slowly matching orbits with each pass; however, at some point, depending on the mass of the target body, the savings from the Oberth effect will outweigh the savings from the gravity assist process and you will be better off finishing the capture with a single burn. This same process (in reverse) works going outwards, as well - I used this trick during the return phase of my Moho SSTO mission.
  7. Foosball. And I agree, the foosball entries were a clever idea. Team 3 got my vote for the forum side, barely. Team 6 suffered from the fact that I watched the videos in numerical order, and also from the fact that I had a conflict of interest.
  8. Not that I don't understand this criticism, but building orbits is every bit as difficult as building spaceships. That said, I disagree that this was a building competition; it was an art competition. We were (tentatively) planning to do something completely different until we learned about the one screenshot limit. At any rate, congrats to all of the other teams. T'were some nice trophies on display. I especially liked forum Team 4; that's an impressive display of building skill.
  9. It's been a while since I've messed around with KSP, but I've been looking for an excuse to play again. This sounds fun; guess I'll throw my name into the hat for teams. I imagine my resume speaks for itself.
  10. "Just." It's called rocket science for a reason; if these things were easy to do we'd be doing them in real life rather than video games. That said, if you think this game isn't for you then that's your prerogative. However, I recommend that you stick with it at least for a while; KSP has a steep learning curve, but the thrill of finally making it to another planet is well worth the struggle. Edit: Really? In that case, something is going wrong. It takes less than 1,000 m/s delta-V to break free from Kerbin's SoI once you are in orbit. Describe to us what you are doing and we may be able to help.
  11. If you have enough delta-V, then you have enough fuel. In rocketry, the two are (for all practical purposes) synonymous. Delta-V refers to change in velocity - it is a measure of how much you can change the velocity of your craft. Note that this does not mean one burn (although it can); it means the total amount of change in velocity that your ship can manage throughout the entire voyage - in essence, it is your budget for your flight. If (according to the maps) you have enough delta-v for your voyage, and yet you are still running out of fuel, then the problem is not that you need more fuel. It's that you need a better (more efficient) flight plan. Getting to and from other planets is hard, but it has far more to do with when you leave and how you travel than it does with how much fuel you have. Almost any craft that is capable of a Mun landing and return can return from Duna - the delta-V requirements are almost identical - but you have to have the right flight plan to do it. The delta-v numbers given by the maps represent best-case scenarios for transfers made during the optimal transfer windows. If you aren't flying during one of those windows, then it can take much, much more fuel (prohibitively much, if you are flying at exactly the wrong time). Nine times out of ten, careful flying trumps exhaustive building in this game. Make sure that the phase angle between Kerbin and Duna is correct before you leave, and make sure you have the right ejection angle when you go - if you do that, then you'll most likely find that the ship you have is already capable of doing the job. (If the terms phase angle and ejection angle don't mean anything to you, then I recommend that you look up a tutorial on interplanetary flight; it's not all that hard once you understand what to do, but it's not intuitive.)
  12. TWR is only an important consideration when you are taking off or landing. For those events, you need to ensure that your TWR is greater than 1 (and that you have enough delta-v to get to orbit). However, once you are in orbit, TWR is no longer important and the only thing you need to worry about is delta-v. For low TWR craft, it will sometimes be necessary to split an ejection burn into multiple parts across multiple orbits, slowly raising your apoapsis each pass then going around until you get back to periapsis for the next burn. However, if you have the patience to do this, then even ion engines are sufficient once you get to orbit.
  13. You can do a flyby of anywhere using nukes, too. Better yet, you can do a flyby, land, and return using nukes on every target except Tylo and Eve, and ions don't help with either of those. So there is no reason whatsoever to use ion engines on an SSTO as the game currently stands; they are unnecessary. Which was my point to begin with.
  14. QED. You want to build multi-stage, and use ions for the transfer? Sure, they're great, if you can tolerate long burns. But if that's what you want to do, why are you talking about it in a thread devoted to the capabilities of single stage craft? I was quite explicit in my above post: ion engines are unnecessary for single stage craft.
  15. There are no targets that you can get to with ion engines that you cannot get to without ion engines. While ion engines give you increased delta-V for the transfer portion of your trip, they are useless (i.e., dead weight) during takeoff and landing. That dead weight is not trivial, and the efficiency loss during landing and takeoff can (and, for most targets in the Kerbal system, does) out weigh the efficiency gains of using ion engines for the transfer.
  16. Ion drives are unnecessary for SSTO spaceplanes. You can make it to and from every target except Eve and Tylo using a nuke, and replacing the nuke with ions won't help for either of those. Eve cannot be done single stage, and Tylo requires stage-and-a-half (undocking a lander from the plane to take down to Tylo's surface, like what Mesklin did with his Dedal craft). None of these trips are new, so they probably shouldn't count as official submissions, but to give you an idea of what is possible with SSTO craft here are the trips that I've made: The Mun, twice. Eve orbit, followed by Gilly and Minmus. Duna and Ike. Dres. Laythe and Vall (simultaneous missions using two craft). Eeloo. Moho.
  17. I'm working on a Cupcake-style VTOL heavy lifter, but I have discovered that I am no where near the caliber of pilot that Cupcake is, and that controlling a VTOL with a keyboard and mouse is bloody hard. If I can just get the modules to dock I should have no trouble at all getting to orbit; the first five meters are harder than the last hundred thousand.
  18. A single stage trip from Kerbin to Tylo and back is not possible using stock parts. The TWR requirements for landing on Tylo and returning to orbit, in conjunction with the delta-v requirements for the trip, leave too little payload to mount the air breathing engines and jet fuel required to get into orbit.
  19. You are right that the air breathing engines add a lot of weight that you have to carry with you. However, the air breathing engines also allow you to make orbit using almost no fuel at all; that's what I'm exploiting for the Moho flight. For all practical purposes, I make it to orbit with that craft fully fueled, so adding a booster would gain me nothing. The reason Tylo might be doable with a booster is that I could build an SSTO that did not use jet engines. While that design would be much less efficient getting to LKO, if I built it correctly it would be more efficient for operations in space and at Tylo.
  20. Am I required to actually use a booster, or can I just fly the missions as an SSTO? Because there's only one target that might be doable using a booster that's not doable using an SSTO without the booster: Tylo. And I've been everywhere else already. Regarding your scoring: Eve landing is relatively easy, and Eve takeoff is impossible (for a single stage craft). Flyby of Moho and Eeloo are about the same, but orbit of Moho is much, much harder. And you should probably including returning to Kerbin in your scoring. As for my submission, here is my SSTO to Moho: Total score: Eve flyby, Moho flyby, orbit, landing, and takeoff; 70+100+25+70+35 = 300
  21. I'm a sympathizer with Hawking's notion that apparent horizons are the key geometric objects and that event horizons are unphysical; however, it should be noted, now and for the foreseeable future, that all proclamations coming from quantum gravity physicists are speculation - and speculation only a half step above nonsense at that. The problem with quantum gravity is that there is a vast dearth of observations and far too many physicists with nothing better to do than sit around making up new pet theories. This includes me.
  22. Not that I've come across. I do it by working my way backwards: start with the final window, and then look for transfers that arrive during that window to determine when you need to leave the previous target. Also, try to match the insertion delta-v from the arriving trajectory with the ejection delta-v of the outgoing transfer, otherwise you will need to make a burn during the flyby. It's a pain, though, and more trial and error than anything else. The best I've managed to work out for planning an itinerary was the Kerbin-Mun-escape-Kerbin-Eve-Kerbin trajectory I used for the walk through at the end of my assist tutorial, and I managed that only because I new I could pull off part of it ahead of time. (Also, it wasn't a perfect chain, but involved a 4:3 Kerbin resonant orbit after the Mun encounter, and a 1.5-solar-orbit transfer to Eve (that is, I circled Kerbol 1.5 times waiting on the Eve encounter.)
  23. Eve ascent takes between two and three times the delta-v that Kerbin ascent requires, and Eve has 1.7 times the gravity as well. So, in the spirit of making a test that is too hard (ie., over engineering), try the following: build a craft that is capable of taking off from Kerbin, reaching orbit, and then landing three times while never using more than 60% throttle. This isn't by any means a perfect test, but it will give you an idea of the requirements without the need to edit your .cfg files.
  24. If I were to try to improve my craft, I'd keep the two jets and scale up to about ~30 tons takeoff weight; I can probably manage ~8.5 km/s dV on orbit if I do it right (Mesklin's design manages 8.2 km/s on 31 tons liftoff weight, and uses a pod rather than a seat). You are right, numerobis, about being able to shave additional dry weight by changing to deluxe winglets. I wasn't really trying to be optimal when I first made the design; the original motivation was a discussion with tavert about doing a double Mun run, so I was just scaling up and improving an old design of mine back from the 0.18 days. I'd build her differently if I were to try again. Regarding rocket-SSTO to Eeloo: I've had a lot of practice with the Kerbin-Jool-Eeloo run between the trip linked above and my work on the gravity assist tutorial, and the best I've managed to date was insertion into low Eeloo orbit for just under 2.5 km/s. Down and up on Eeloo will run another 1.2 km/s, and it takes 300 to get back to Jool (and back to Kerbin for free from there). So, a perfect trip using that route will run you ~4 km/s; in the ballpark for a rocket SSTO, but only just. There are additional tricks you can use to shave off up to another 1 km/s, though. One way would be to use multiple Kerbin encounters and a series of deep space maneuvers in route to Jool (metaphor had a good pattern for getting there in his single launch Grand Tour post, and told me he saved around 500 m/s over a direct transfer). Another is to go Kerbin-Eve-Kerbin to get a boost. The problem with either of these methods is timing your arrival at Jool so that you hit the window to get to Eeloo (it's a long window - several weeks leeway on either side - but it happens infrequently, and doesn't often line up with an efficient transfer from Kerbin).
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