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kodack

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    Bottle Rocketeer
  1. We are not NASA because we are not primarily administrators and engineers. How about a "we are not JPL" thread.
  2. It's a simple thing to check but make sure all of your thrusters are turned on. If even a single one is off it will cause you to flip out of control. You can also make sure that the thrusters are straight and haven't been tilted when you built it. As someone else suggested double check your COG in the building area and make sure it's dead center. One more thing, if you are using both sets of thrusters....don't. A rocket is most stable with thrusters at the back, pushing.
  3. I felt bad The face he made as he desperately tried to jetpack himself to a stop was priceless. A big frowny face turning into clenched teeth as the ground came up to introduce itself.
  4. I thought it was a space Kraken orbiting out by Duna looking for craft that are going way too fast and then devouring them.
  5. The devil is in the details. For instance when you need more lift you jump to giving it more wing. Why not replace the delta with a higher lift wing so you get more lift without more weight? When I'm not building large, beastly, over the top, vehicles my motto is less is more. Try to make every part serve more than one purpose. Instead of having a fuel tank, and a fuselage, combine them. Instead of adding more control surfaces to handle a shifting CG as tanks empty, reposition the tanks so the CG works for you. Instead of adding more jet engines to get it off the runway, consider changing your center of lift to help get the nose up. In extreme cases, consider a vertical takeoff. It's still SSTO and a spaceplane if it launches vertically so long as it can land horizontally.
  6. I think if it had taken off smoothly the video wouldn't have been as entertaining. I found this out in the second video when the perfect liftoff was quite boring, so I cut to some of the unfortunate casualties in my testing program. I still want to know why my Kerban got punted out of his cockpit at hypersonic speed after going EVA at 1:36.
  7. Undoubtedly. I tried a few different rocket engines in designing this and went with aerospikes as much for their average efficiency as their compact proportions which didn't put my CG too far aft. Pairs of rockets are the way to go imho. Pairs of jets can be problematic due to the tendency to get into unrecoverable flat spins when one engine cuts out from the other due to low oxygen. I am able to push longer and more reliably with a single jet engine, as a flameout has little impact on my mission, I just switch to aerospikes.
  8. Your SSTO has un-needed bulk and weight. With SSTO, weight and fuel economy (specific impulse) are your two worst enemies. In my craft I have 2 small rocket fuel tanks into aerospikes, and 1 mk1 fuselage giving fuel to a turbojet engine, and 3 ram air intakes. This is enough for 130km circular orbit with about 1/4 fuel left over. You will need to make the most of your jet assisted boost by making a very shallow climb so that you prioritize speed over altitude. You need that air hitting you fast so the ram air can do it's job and keep your engine going. You should be able to make it to 21,000 meters and 1400m/s speed at which point you engage the aerospikes to insert into LEO, before your apoapsis you do a stablization burn to insert yourself into orbit and at that point you can do an altitude burn to get up to 130km or so.
  9. Wasn't going for most fuel tanks or thrusters. I wanted a heavy lifter "mobile parking lot" with a large surface area for a mobile base. This was my first prototype. Out of curiosity though, knowing that I pushed the game to nearly game breaking levels, who put a larger rocket off the ground?
  10. What do you guys make of 1:36 in the second video. I thought I had survived it but the moment he stepped foot outside the capsule he got catapulted at incredible velocity out over the ocean. The only thing that makes any sense is that it's either a bug, or explosions can propel nearby objects to insane speeds.
  11. I'm back with part 2 of "The Big One". I optimized my strut arrangement to stiffen the chassis without adding too many more parts. The result is a very stable launch vehicle. However the extra parts pushed the total part number to over 1,100 which has slowed the framerate even further. This launch is 20 seconds thanks to speeding up the video by 16x, but that 20 seconds took over 20 minutes to play out in real time. The average framerate was far below 1 fps. I'm not sure what happened to our Kerbalnaut that turned him into a screaming and quite frightened projectile but it did not end well. Finally at the end of the video we have 1 sole survivor. The two explosions were earlier attempts at creating a stable launch vehicle.
  12. I wasn't sure what the actual measurements for fuel were in the game. I assumed that the "units" in the description screen were tons, so I multiplied by the number of fuel tanks. It seemed small but it was a napkin calculation. Love that rocket in your screenshot. What a beast! PS I have worked out the flex issues and been able to add a few more struts, while reducing my overall number of struts. I have just achieved a stable and flex free liftoff but the framerate took a major hit with the additional parts needed to stiffen it. I let it run for 20 minutes and got about 20 seconds of in game time. Average was less than 1 fps. I'm editing the video to put up. I also found a strange bug that can put an EVA pilot flying through the atmosphere from the ground at spectacular speed.
  13. This is my SSTO craft. Total time to orbit, about 15 minutes. It goes faster above 5km. Parts: Mk2 fuse, 3 ram air intakes, 2 aerospike engines, 2 rocket fuel tanks, 1 turbojet engine, 1 flt400 fuel tank, 3 landing gear, 2 delta wings, 1 avr8 winglet. Connect them in the configuration observed in the video. You will want to position the wings and Jet motors in such a way that your center of lift is slightly behind your center of gravity for maximum stability. *note* I chose to save weight and not use SAS. You may easily add one in between the ram air intake and the fuselage if you want an easier time of it. Instructions:Take off with the left and right ram air intakes closed on jet engine. Gain altitude to 10k as fast as you can, IE straight up. At 10k level off and gain max speed, climb steady to 15k, open ram intakes, make shallow ascent for maximum speed. Your goal is 21,000m 1380mp/s at which point you will engage the aerospikes to insert into 130KM orbit with 1/4 fuel left. Win. simplest I've been able to create.
  14. One more thing I forgot to mention, The game is not happy about loading, or simulating this craft. I've crashed to desktop on numerous occasions while working on it. It was a stroke of luck to be able to capture an actual flight.
  15. So in answer to some questions. 1. It started out at over 450 rockets but it became tedious to load or make changes to it. Plus it blew up on the launch pad as it was much larger than the pad itself. 2. The limits I'm encountering in the game have to do with the number of parts and not necessarily the number of rockets. Without struts to stiffen the chassis it won't lift off at all. However, in order to make it truly stable, I would have to strut every fuel tank, to every other fuel tank, which exponentially increases the part count. Im trying to get the most stable craft possible with the minimum number of struts in order to keep parts counts low. This was my first successful liftoff and it showed me that I need to at least re-strut the outside banks of rockets so they don't flap about. Given the extreme load times, and low frame rates of down to 0fps when experimenting, the work is understandably slow. The ultimate goal is to build a kind of flying parking lot which will act as a mobile launch center or landing pad, and land it somewhere else on the planet for use as an experimental test range. I want to construct buildings and use this beast to move them to their location. Several missions later and I should have a flat area with buildings large enough to stage from or land on.
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