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Geometrian

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Everything posted by Geometrian

  1. After a series of incredibly dumb failures exploring the Jool system in career mode (ranging from not executing landing burn soon enough, aerobraking too hard, running out of fuel, time warping fails . . .) I finally decided to get it right. I was at my first destination, Bop, and had lowered my orbit nice and low--so low that it required 1x time warp (I believe this is significant). However, it was in a perfectly reasonable, stable orbit. I had to orbit just a half orbit more, and figured I'd switch to the KSC and warp ahead. But when I looked in the planetarium, I couldn't find my beautiful spaceship. It had been eaten! --- I believe the relevant factor is the altitude. The orbit didn't intersect Bop (and the ship disappeared exactly when I loaded the KSC), but I had been switching around just fine at higher altitudes before.
  2. I have discovered something interesting: if you enable infinite fuel, jets work in space. They have around 1kN to 3kN thrust.
  3. The important thing here is that the jet is at full thottle. It's relatively simple to get low thrust just by setting everything lower (for example see the spoiler). I have clarified this in an edit.
  4. Challenge: Using only jet/turbojet power, what is the highest apogee from Kerbin you can get (stock parts and stock aerodynamics)? My current record . However, I'm kinda betting that it might be possible to get escape velocity by using more jets.Because of this, I'd like to split this challenge into two categories: Using only one jet/turbojet Using any number of jets/turbojets Your craft does not have to be an SSTO, but all power in each stage should derive from jets. Bonus: if escape velocity is indeed possible, can you get interplanetary travel using only jet propulsion? A one-way trip would be impressive enough, if only for the required precision alone--but maybe you can, for example, get to Laythe and back using only jet power?
  5. Challenge: achieve the lowest possible thrust from a turbojet without flameout (stock parts only and stock aerodynamics). Here's my record 3.9kN: Additional rules: Thrust must be computed on the upward part of the trajectory (+/- maybe a few seconds). This is because when reentering, thrust can be made arbitrarily low without flameout Your craft should use only the turbojet (or turbojets) to reach altitude and speed. This is mainly for a similar reason. Obviously, throttle must be full open.
  6. I've noticed that KSPInterstellar exaggerates the problem. Here's an attempted SSTO burning blue: I've noticed that in this case, the engines power off automatically. I believe this is KSPInterstellar's doing. The exact same aircraft without it doesn't overheat. Though, it doesn't get to orbit; for that you need this:
  7. Landing on Minmus with a jetpack is a . Get a ship in low orbit, then jump out and thrust backward. Minmus's low gravity (0.491 ms^-2) and relatively fast rotation (11h 13m 20s) mean that the relative velocity of landing on the surface isn't much. Getting back into orbit is easy if you time the rendezvous intelligently. I've contemplated going twice in one run.Landing on Ike, though . . . They said it was impossible. Technically, it is. Ike has well over twice stronger gravity (1.10 ms^-2) and a slower relative rotation (18h 11m 58s). The lowest energy stable orbit I got was 325m/s relative to the surface. Since a jetpack only has 600m/s dv and crashing a Kerbal at >50m/s to make up the difference doesn't sound survivable, well . . . This all occurred in my Duna mission, whereupon it was realized that fulfilling both contracts (Duna and Ike) at once wouldn't work with a one-time lander. After getting into orbit around Ike I got an idea: stop the ship. Just bring the ship to a dead stop over the surface, drop the kerbal out, and then accelerate back up to orbit. Switch to the falling kerbal and use the jetpack to break the fall. Land and do all the science. Getting back to the ship is much harder. You need to jetpack upward, and simultaneously stop the ship exactly so that the altitude, speed, and position all match. Stopping the ship means of course that as soon as you switch to the kerbal, the ship will start falling. In practice, though you can boost upward periodically to compensate, the timing tolerances are too tight to also control the kerbal to a rendezvous--and altitude loss is unavoidable. So, you'll get a hair-raising near-surface rendezvous, after which you immediately blast off back into orbit, just seconds before slamming into the ground. The difficulty here is managing the actions of two different vessels, one without a HUD to tell you where to go. I succeeded after several tries, although it could be easier with a different ship. Also, I lost all the science due to a bug
  8. Eh? Actually, since the thing rides close tolerances all the way up, it takes both a lot of skill and concentration to power the ascent, which, since the gravity turn doesn't happen in atmo, is briefer than a chemical rocket. Good question. I meant monopropellant-power only. It has lower specific impulse, which is why it's difficult. Compare the O-10 (290s) and the RV-105 (260s) best case versus e.g. Mainsail (320s) worst case. Generally the difference is more like 50%-100%, which starts hurting a lot for a SSTO.
  9. It could be either. The body need not completely occlude the other. For example, annular solar eclipses. At the scales dealt with on Earth, people tend to use "eclipse" for sun/earth/moon events and "transit" for sun/other-planet/Earth events. Speaking as someone who knew the difference IRL, but still screwed up, I think it's just that "Lunar Eclipse" makes sense as an event involving the moon, so it's the first thing people think of. "Solar eclipse" IMO is sortof an unfortunate name.
  10. Gack. Yes. I said "Munar Eclipse" to differentiate it from a "Minmusar Eclipse". It's not a problem on Earth since we only have one moon. I suppose such a culture would have to find new terminology. I think "Kerbolar eclipse of the Mun" is the best solution.
  11. I was just about to launch a 100% ion SSTO (which on further examination, actually wasn't). When dawn came, I got the most picturesque Munar eclipse ever:
  12. Nope. My install is entirely stock. Not even MechJeb. Put three Rockomax 24-77 engines spaced around a turbojet output, angled two "SHIFT+W"s inward. That makes a fairly stable example for a turbojet.It's also possible with a standard jet engine:
  13. After a SSTO was destroyed at a critical moment, I reproduced the problem: overheating. It turns out that overheating jet engines glow blue (which makes some kind of sense, but I didn't realize was implemented): I hadn't seen anyone notice this before, but I thought it was kindof pretty. The small rockets are angled toward the jet; the screenshot was taken a few milliseconds before the jet exploded.
  14. I had a goal of making a SSTO using only RCS thrusters. No rockets. No jets. No ion engines or sepratons for a boost even. I failed miserably, but today I decided to have another go. I succeeded, and the result is essentially just some on the larger RCS tanks stacked on top of each other. This seems to be semi-identical to the very few other success stories out there. Here's the .craft file, in case anyone's interested. Directions included. The title is a bit of an exaggeration; this one can get to over a 200K orbit, so it could do a 100K orbit and deorbit easily; early versions were not so lucky. Bob, you will be missed. Anyone make an actually elegant RCS SSTO?
  15. I present a not-particularly-pretty, but surprisingly functional SSTO cargo plane. It has a large bay for storage, several docking ports, RCS maneuvering, and a bunch of other neat and handy features. .craft Here's an album of it returning a 1.25m satellite from a previous program for salvage. Note that at no point does the satellite actually dock with the plane! Uses part clipping for the landing gear and rear engines. Entirely stock.
  16. Hi, I present the true story of deorbiting "Ionic Sputnik", an ion-powered probe that has "lost" all power. The trick is trying to save it, despite no parachutes, no rockets, and no way to grab it. The only thing available is an aging X-3 SSTO spaceplane and star pilot Bill Kerman . . . -G
  17. Your space station is very impressive, Rune! I tried to make a SSTO using only RCS, but it wasn't close to working. However, I noticed that the chassis I built had really interesting aerodynamic properties. It can glide essentially indefinitely, kinda hover in the air, turn very quickly, and is very stable. It's not very unique-looking, but it flies the best out of anything I've ever made. So, I swapped out the RCS tanks for a jet tank and immediately produced the following SSTO: Ascent is fairly standard, except because it is so light the jet can do almost all the work. I coaxed it to a top speed of 2211.1 m/s using the jet alone! This is enough to have its own periapsis. The orbital insertion was made through the RCS thrusters only. This is the .craft file, I think: .craft
  18. I had tried that strategy on a post above. The quote returns e.g.: <url>http://imgur.com/a/eUAtH</url> except with square brackets for the "url" tags, and "view source" returns e.g.: <iframe class="imgur-album" src="http://imgur.com/a/eUAtH/embed" frameborder="0" height="550" width="100%"></iframe> Yup. By airhogging, I assume you mean just using the jets to do most of the acceleration?Anyway, to get the Sunfish to orbit, you launch in the early morning, climb at about 45 degrees up (sharper is too slow). Start leveling off in middle atmo, and accelerate to about 1400m/s. Then, very slowly climb towards the upper atmosphere, and should should be able to accelerate to 1600 or 1700. The sun should be just about overhead. Angle 45 degrees upward with the dregs of the jet, and turn on the ion engines full blast. Also engage forward and upward RCS. Using all of this, you should just have enough to get the apogee to over 70,000m (I went for 71,000, I think). Be sure you save enough RCS/electricity to rotate back so the batteries can recharge. Once you reach apoapsis, burn forward. I ran out of power before the end, but the periapsis was 68,000m, which was easily corrected on the second orbit. Maneuvering in orbits is pretty easy though. I docked it with an X-3 (another SSTO) in 100,000m orbit (the X-3 had to do the RCS, though) intending to rendezvous a tug with both of them and pull them to a refueling station. It was too buggy for that, so I deorbited the tug, separated the X-3 and Sunfish, and brought both of them to the station under their own power (the tug idea was really just for fun). -G
  19. Hi, The part count on my OP is 56, I think. I added an octostrut and antenna on the front though (so now it's 58). I think actually it has a KW Rocketry nosecone, so it's not quite stock. I've been playing around with this a bit, and I now present the Sunfish, named for its shape: imgur.com/a/eUAtH Bleh; how do I embed an Imgur album? It is horrifically impractical. I had to use RCS just to get enough altitude, once the jet cut out--and don't even think about trying to liftoff when it's not morning. Even with 14 ion engines, it's underpowered (the thrust to weight ratio is bad, and adding more ion engines will actually make it worse). However, prettiness will not be denied . . . .craft
  20. Hi all, I present a SSTO that uses a single turbojet and two ion engines to reach orbit: It has a small docking port and RCS controls. I have found it quite easy to fly, and quite easy to reach a pretty high orbit (~120,000). It uses part clipping in a "fair" way: there's an RCS tank inside the empty space in the nosecone, and the front landing gear retracts into some empty space. The jet fuel tank is collocated with the fuselage for space concerns, but not all of it is necessary to reach orbit by a longshot, as the screenshot shows; just imagine only the side/bottom parts of the tank are filled .craft -G
  21. Challenge: On any body of your choice, set up the lowest orbit possible. The orbit must be stable for 300 seconds after the submitted image. For example, my attempt on Minmus (taken a regrettable few seconds after perihelion, where it was about 2/3 the height):
  22. The following is a dramatization of one of my first landings. Note that the language deliberately does not restrict it to KSP.
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