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OhioBob

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  1. OhioBob
    Is the following case sensitive? Try it without the all caps. @Kopernicus:AFTER[KOPERNICUS] https://github.com/Kopernicus/Kopernicus/releases/
  2. OhioBob
    To complete the three launches more quickly, it would actual the beneficial to boost the satellites into even higher orbits. The more slowly the satellites orbit, the less time it takes for Kerbin to pull 90 degrees ahead. If the satellites had orbital periods of, say, 900 days (a little beyond Duna's orbit), then the time between launches is, 90 / ( 360 / 426.09 - 360 / 900) ) = 202.3 days The transfer time for each satellite will be longer, but the overall deployment time should be less because there is less wait time between launches.
  3. OhioBob
    Transfer time isn't important in determining the time between launches, but it does factor in to how long the entire process will take. What's important for determining time between launches is the angular velocities of Kerbin and the satellites in their final orbit. Kerbin's orbital period is 426.09 days, and let's say the satellites have an orbital period of 604 days. The angular velocities are, Kerbin: 360 / 426.09 = 0.8448919 degrees/day Satellite: 360 / 604 = 0.5960265 degrees/day Each day Kerbin will move farther ahead of the satellite by an angle equal to the difference in the angular velocities, i.e. 0.8448919 - 0.5960265 = 0.2488654 degrees/day. So for the next launch to occur, Kerbin needs to gain 90 degrees on the previously launched satellite. That takes a period of time equal to, 90 / 0.2488654 = 361.64 days. The total time to complete is the time between launches plus the transfer time of the last satellite, 361.64 * 3 + 256 = 1,341 days.
  4. OhioBob
    You're right, launching them 1/4 of an orbit apart doesn't work. I think they need to be launched about 362 days apart. If we assume we're placing the satellites in an orbit halfway between Kerbin and Duna, and we're using a Hohmann transfer to get them there, then the transfer takes 256 days and the final orbital period is 604 days. If the first launch occurs with Kerbin at 0 degrees longitude, then when the first satellite arrives in position, it will be at a longitude of 180o and Kerbin will have raced ahead to 216o. In order to create the 90o separation between the satellites, we need to wait another 106 days before launching the second. In another 106 days, 362 days since the first launch, Kerbin will be at 306o longitude, and the first satellite will be at 243o. If we launch now, the second satellite will be in position 256 days latter. At that time the first satellite will be at 36o longitude, and the second will be at 126o, i.e. 90 degrees apart. That means the whole process will take over 3 years to complete.
  5. OhioBob
    He said he wants to place them between Kerbin and Duna, so we're looking at a solar orbital period of about 600 days.
  6. OhioBob
    ASLgravity modifies the acceleration of gravity at the surface. So having it set to 1 means that all the bodies have the same surface gravity that they do in the stock game, i.e. Kerbin's surface gravity remains 1 g.
  7. OhioBob
    That makes more sense anyway. In real life we can't change a planet, so we just recalibrate the instrument. Personally, I wouldn't want to make a change of the scan heights as an official part of GPP, but that's not solely up to me. The heights are what they are and that's what everyone who uses ScanSat is use to. Changing it might just freak people out. If there are a couple planets that can't be scanned, I'm not bothered by it. The scan heights are known and the atmosphere heights are known, so it's up to the player to put one and one together and release you can't do that.
  8. OhioBob
    Well, you're out of luck then. I don't want to change the atmospheres just for that one instrument. If you can't get close enough to do a scan, then so be it. It's not going to work at Nero or Sarnus either.
  9. OhioBob
    I forget, what the optimal altitude for a biome scanner?
  10. OhioBob
    Let me correct myself. I know that gas giant can be scanned. What I really meant to ask is what is the usefulness of it? Since there is no surface, what data is there that can be obtained by doing a scan?
  11. OhioBob
    Can you scan a gas giant? I didn't even know that was possible.
  12. OhioBob
    The datum by which elevation is measured is a perfect sphere, but the planet itself can have quite a bit of irregularity. But I assume it was the datum to which you were referring. In real life a celestial body's datum is often a spheroid.
  13. OhioBob
    When you have a group of satellites working together like that in a coordinated way, I've just typically heard it referred to as a satellite constellation. The type of orbit that those satellites are in can be a variety of things. For instance, it's possible that the satellites could be in "synchronous orbits", but that's because they are synced to the rotation of the planet, not because they are synced to each other.
  14. OhioBob
    That's probably what I'd do. Just make it four separate launches, each separate by 1/4th of a year. (edit) This won't work - see follow-up discussion. By the way, I don't think "synchronous orbit" is the correct term for what you're describing. A synchronous orbit is one in which the orbital period of the satellite is synchronized with the rotation period of the planet.
  15. OhioBob
    Nothing like that presently exists. You could use Gordon's Tellumo home world config, and then modify Tellumo's properties to make it easier.
  16. OhioBob
    @Gordon Fecyk wrote a config that makes Tellumo the home world, and I wrote configs to modify the engines for Tellumo. You can try it out if you want.
  17. OhioBob
    You have to be careful with the Renamer, but other than that you should be good. If your previous installation did not include the Renamer, then continue your current game without it. After installing 1.5.88, delete the folder GPP_Renamer.
  18. OhioBob
    I don't know where this question belongs, but I thought the Kopernicus guys might know the answer. ScienceValues are assigned in a planet's cfg file, but what about Kerbal experience points? I've never seen anything like that in the Kittopia dumps. Is there some way to specify how many experience points are granted for achievements like orbiting a body or planting a flag? And if not, does anybody know how it's currently done? Obviously the stock bodies already have point values assigned (see here), but what about new bodies added using Kopernicus?
  19. OhioBob
    I problem I see with drop tanks is that decouplers and nosecones in KSP and ridiculously overpriced. I haven't done the math, but I wouldn't be surprised if in some cases it might actually be cheaper to lug the empty tank along with you and just pay for some extra fuel.
  20. OhioBob
    The only other disadvantage that I can think of with this type of arrangement is that the center engine burns from liftoff all the way to orbit. The engine can be adapted to perform best under only one of those conditions - sea level or vacuum. We're most likely to use one of the booster engines designed for best performance at or near sea level. Therefore when we get to near vacuum conditions, we're using an engine that will deliver a lower specific impulse than we would typically like to have. That's going to cost some delta-v. However, I think some of the other advantages of this type of launch vehicle, i.e. all engines being used all the time (no dead weight), makes it worth using. The advantage of a vertically stacked two-stage design is that the engines can be optimized for the particular environment in which they'll operated, providing better overall specific impulse.
  21. OhioBob
    One problem with this, which you allude to, is that the time between favorable launch window will be extreme. When departing from Kerbin you'll have launch windows to each of the outer planets about once every year. This is because Kerbin is orbiting really quickly in comparison to the outer planets, so it catches up with them in a relatively short amount of time. Proper phase angle alignments occur frequently. Jool on the other hand is a slow orbiting planet, so it takes a long time to catch up the outer planets. Proper phase angle alignments will occur very infrequently. The time between launch windows can be measured by the synodic period. The synodic period between Jool and each of the OPM planets is about, Sarnus - 19 years Urlum - 13 years Neidon - 12 years Plock - 12 years By the way, GPP is in the process of releasing an update. If you plan to download it, make sure you get version 1.5.88.
  22. OhioBob
    Another technique that works well but is not as complex to set up is onion staging. In onion staging all the engines run off the propellant in the outboard stages first. When that propellant is gone, the outboard tanks and engines are jettisoned, and the rocket continues running on the center engine with a full fuel tank. This works really well when you set it up with three identical stages side-by-side. It looks similar to the Delta IV Heavy but with fuel lines feeding from the outer tanks to the inner tank.
  23. OhioBob
    The configs files give maxThrust and atmosphereCurve. AtmosphereCurve gives the specific impulse, and maxThrust is the thrust in a vacuum. The fuel flow rate at the 100% throttle setting is computed from maxThrust and the vacuum Isp. At other pressures the thrust is computed from the fuel flow rate (adjusted according to throttle setting) and the Isp obtained from atmosphereCurve.
  24. OhioBob
    Isp is obtained from atmosphereCurve. Here's and example from the Mainsail: atmosphereCurve { key = 0 310 key = 1 285 key = 9 0.001 } The first number is the atmospheric pressure (in atmospheres), and the second is the Isp. So the Mainsail's vacuum Isp is 310, at 1 atm it is 285, and it goes to nearly zero at 9 atm.
  25. OhioBob
    For getting to orbit I use a very simple rule of thumb that works nicely. Using two liquid fuel stages, the second stage (upper stage) should contain a mass of propellant equal to the mass of the payload, where the "payload" is everything that sits on top of the second stage (including fairings, decouplers, etc.). And the first stage (lower stage) should contain a mass of propellant twice the mass of the payload, or twice the mass of propellant in the upper stage. Any additional stages, such as required for an ejection burn, are designed as part of the payload. Requirements for those can vary widely depending on the mission.
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