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sevenperforce

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Everything posted by sevenperforce

  1. I don't think they'd be able to get it into lunar orbit, even if that were true.
  2. While I'm a fan of the spirit of the challenge, it's really not a good idea to offer bonus points if entrants over-design their vehicles to match something that is a problem with your own entry.
  3. Brachistochrone trajectory. Yes, that. Thanks ! The point is that trajectory problems are nearly infinite - you can't tell the trajectory just by knowing the start and end positions, but you can easily do the reverse. A Hohmann transfer is one end of the spectrum; a brachistochrone is the other end. The Hohmann transfer is the lowest-energy transfer which always exists; the brachistochrone is the fastest transfer possible. A Hohmann transfer is not necessarily the cheapest transfer in all cases. Depending on the orbits you are transitioning between, it may be possible to do a cheaper (though much longer) bi-elliptic transfer. However, bi-elliptic transfers are not possible for all possible origins and destinations, and they are not discrete, whereas there is only one solution to the Hohmann problem for any given system. A brachistochrone requires a minimum TWR to be viable; if you have very high specific impulse but low thrust, you end up in a spiral rather than a proper brachistochrone.
  4. Docking ports must move 5 meters apart before they can redock. Unless you quicksave and quickload, which resets the redock.
  5. Keep in mind: the longer the injection burn, the longer the insertion burn.
  6. I built stock landing legs using a pair of stock hinges and made them lock with Clamp-o-Tron Jrs. Once released, they drop down and a pair of docking ports catches and locks them. The actual ground contact is a closed landing gear piece, and there are wing pieces around them to give them shape. The deployment must be right before touchdown or drag keeps them from dropping (as it should be). Unfortunately I've had hinge problems in 1.4 so I should probably rebuild them from scratch.
  7. And, now that we successfully made it to orbit, here's the rest of the mission flown in KSP:
  8. I have not heard an S1 entry burn callout. That's typical when there is no boostback burn.
  9. Mach 1! On topic, here's the preflight for my mockup of this mission: MECO! "Right now the first stage is performing an experimental landing maneuver."
  10. CRS-14 This will be my first Dragon mission, so I had to go ahead and build the Dragon 1 from scratch. There's not actually any interior space, since there's no way of getting anything out. But it doesn't look half bad...
  11. The space junk removal experiment is stored internally and will be deployed through the Japanese module, but it is also carrying an experimental cryogenic propellant transfer module in its trunk!
  12. https://aviation.stackexchange.com/questions/22880/can-you-become-a-pilot-with-an-asperger-syndrome-diagnosis-in-europe
  13. This booster will be expended to test high-energy entry and low-margin landings.
  14. Transmutation, technically. Neutron capture turns protium into deuterium and deuterium into tritium. The odds of any protium atom experiencing multiple neutron capture events while being pushed through a NERVA core are vanishingly low, but since it's technically possible, the exhaust is classified as potentially radioactive.
  15. Tiagong-1 was basically a Svedska module, right?
  16. Clearly they bought the DLC; that's a thrust plate.
  17. New Russian ICBM: Let's see here. Powder-charge-launched. Hypergolic, by exhaust plume color. Likely a two-stage, given the shock diamonds of the underexpanded engine. Single engine, too, so probably a GG or ORSC cycle. RD-275M, maybe? Ridiculously dangerous.
  18. Methalox is a good choice for Mars because you can eventually make your own methane on Mars. Hydrolox is a good choice for the Moon because water ice is about the only thing you can hope to get. A good solution for the Moon...particularly because it's quite nearby...is to leverage hydrolox's ridiculously good isp to get single-stage orbit-to-surface-to-orbit cyclers, shipping hydrolox tankers from Earth to refuel for now, and enabling surface ISRU refuel later on down the road.
  19. I'm not so sure. It sounds like the above says that SpaceX already had its license for today's launch, and one of the "conditions on their capability" was shutting down the feed past SECO-1. Very stupid.
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