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Jod

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Everything posted by Jod

  1. Yes. And then correct the speed slightly to get capture. Usually 50-100 delta v is enough if you do it 1 orbit in advance, the maneuver node is handy at that point. *Not Kerbin. Kerbol. The Sun. Though I've never went to Jool in this way. Mostly Eve. And 1 trip to Duna where I crashed into some mountains during reentry.
  2. Put. The aerospike. In. The FRONT. If you've tried everything else - it is most definitely Drag. Drag center is shifted too much by a massive 1.5 t aerospike with a low drag coefficient 0.1. You need the aerospike in front of your center of mass. I've done several aerospike craft and unless I put aerospikes in the front - they all flip at high speeds on these altitudes. Here are some pics to show possible designs. Also consider using ram air intakes, arranging them symmetrically and moving them to the back.
  3. I've eyeballed Eve and Duna if you could call it that. I just eject myself to prograde/perigrade, set my periapsis/apoapsis to touch the planets orbit and wait for the planet/myself to catch up as if it is a rendezvous. Takes a while, but eventually when I am close enough I set a maneuver node and correct my speed slightly at the point where my orbit touches the planets so that in the next rotation i would get capture. I mean, it's kerbals. They can wait a couple of years in space.
  4. By "strapping" I meant attaching them to the cargo bay Sr clampotron of the WIP freighter transport. And I usually like adding a lot of different size docking ports if I'm not squeezing delta v out of that particular craft. The station looks like this btw: The stripy parts - not decouplers, they are all Sr. clampotrons and one ASAS. I usually do the gravity turn at 25 000m, the atmosphere is too thick below that. The station core is usually really heavy, if you are not using jet engines then you will definitely need mainsails and orange tanks.
  5. Umm... I could be wrong, but if you are around Gilly then it is probably easier to just leave Eve SOI and transfer while you are in Kerbol orbit, not to burn your way to the planet for an assist. Seem like counter-productive maneuvers to me.
  6. A very small and light lander is the only thing that can get through Eve atmosphere up to sub-orbit. I don't care if I'll have to build the USS Enterprise and burn mainsails to catch it.
  7. I patched my first station together from random scrap I was strapping to my WIP freighter that I tried to consistently get into orbit at the time. One equator full of debris later - about 5% of fuel/RCS/docking port modules actually made it into 150 km orbit and docked. The freighter also started behaving properly after, like, Mark VIII or something.
  8. Ok, so I guess it is possible then. I will keep trying.
  9. I'm asking this because I'm still considering an Eve single stage lift-off mission. Math says I have enough delta-v to get into sub-orbit but not enough to circularize. I don't throw away any stages in my playthrough but using tugs is ok.
  10. Has anyone done this? The idea is to get a craft into sub-orbit(as in, high enough that it is in space but not fast enough to stay in orbit), then dock a tug to it and push it into a stable orbit. I am guessing it would require an extremely precise and fast rendezvous and docking operation, how hard exactly is that?
  11. I have taken a probe up to 90 000m with some fuel to spare and posted pics in post 47 of this topic. A seat can easily be added for transporting kerbals. http://forum.kerbalspaceprogram.com/showthread.php/34221-Eve-SSTO-possibility?p=440941&viewfull=1#post440941 It is indeed a trivial task to launch a rocket SSTO to Kerbin orbit. But it takes only 4000-4500 delta v, less than half of what you'd need on Eve. As for the fuel mass - yeah, as I've said you will need at least 5/6 of your craft mass to be fuel even if your average Isp is around 500. Aerospikes alone won't cut it by any means.(dry/full ratio of 1/9 which is impossible with current fuel tanks provided you don't drop them) Also - I've just managed to leave Kerbin SOI with that thing: Edit: tried 1 aerospike-1 LV-N combination, turned out it actually is more efficient, gave me around 6000 delta-v easily. Could probably squeeze an extra 1000 dv out of it. Still not enough though.
  12. Tried both configurations, 24-77 give slightly more delta v than aerospikes because their weight is smaller, improving the full/dry mass ratio. Still not enough for Eve, though I'm a horrible pilot. Maybe an ace could pull something off.
  13. I see only one problem: 1. 2 m/s^2 maximum possible acceleration even when in space. It's like watching paint dry. In slow motion. As for infiniglide - yeah... I am currently considering the whole aerodynamics in KSP as a one huge bug. I'm thinking of just dropping the whole winged craft idea for Eve. You just can't compensate for fuel mass with lift because drag eats every last bit of your delta v that way. Even on Kerbin I find that vertical ascent saves huge amounts of fuel. So far - the best configuration I came up with is an LV-N with Rockomax 24-77 boosters that are used to blast through the thicker atmosphere. And that is not even close to 8500 delta v at 1.7 TWR, more like 6000 delta v provided good piloting. I will try to squeeze more out of it but it seems i will need a second stage eventually as i just don't have the required Isp to keep all my mass with me.
  14. Your speed in orbit creates centrifugal force that counteracts gravity, more speed = more centrifugal force that pushes you into higher orbit. Hence no increasing velocity and staying at the same height. That is the simple explanation that does not involve vectors. If anyone is interested how it really works in vector form then there is only one force - gravity, that constantly changes the velocity vector even in circular orbit because rotation is in fact a change in x/y/z components of the velocity vector. By increasing your velocity using thrust, the same change from gravity force accounts for a lesser angle change because your velocity vector is now larger, hence you get a more elliptic orbit because it takes more time for gravity to rotate your velocity vector. The only other way to keep your position stationary besides GSO is constantly burning fuel, basically hovering above the point you want. Orbits are freefall, you can't just throw a ball and expect it to obey your will mid-flight, physics don't work that way.
  15. Well, it is possible with mods, there is a challenge for that. This topic is more about Stock parts. The Rockomax 24-77 + ion engine combo is a bust. It is possible to make Kerbin orbit but ion engines have no effect whatsoever during ascent and even circularization due to empty fuel tank mass they have to tow. I used 24-77 specifically because their weight is very very low so all I had to deal with was empty fuel tanks. Along the distance of 1/4 of the equator the ion engine failed to increase delta v sufficiently. Also tried the aerospike + 2 ion engines combination, same result. Liquid engines require a lot of fuel tanks that even when depleted hinder ion engine thrust. I will check the math to see if creating a pure ion-powered glider is possible. I think I saw one of those on the wiki, though I'm not sure if it can reach the needed speeds before getting to the dark side of the planet(or driving the pilot to insanity). Something tells me that getting sunlight would be the least of the problems.
  16. That is why standard procedures require to start leveling the craft as early as 40 000m. I'm talking about circularizing an orbit that covers at least 1/4th of the equator. Massive crafts are out of the question though, ion engines simply won't move them fast enough. Something in the range of 6-10 tons when all fuel is depleted can theoretically gain some good delta v from ions, anything heavier will not accelerate fast enough and lose orbit. And I'm talking really small. Like, Rockomax 24-77 small. I'm going to test a 2 Rockomax 24-77 + 1 ion engine setup soon. So far, 1 LV-N + 4 Rockomax 24-77 are quite a bit more efficient than 1 aerospike, provided 24-77 are not used all the time but only when needed. Here are some screens of my test flights: Made it into Kerbin orbit with some fuel to spare on an LV-N with four 24-77 boosters. The fuel left was enough to push apoapsis up to 500 000m. Taking off with all boosters enabled. Half of the fuel is consumed in the first 4000m. Also - I found out that aircraft landing gear weighs 0 kg for some reason. So all my efforts at attaching rover wheels were in fact making the TWR worse, will revert to aircraft landing gear soon. Taking an SSTO without jet engines into Kerbin orbit should be a challenge or something... With winners trying their craft on Eve. Anyone wants to start one?
  17. Try moving the aerospike to the front of the plane and air intakes to the back(do you close the intakes when you turn off the jet engines?), that helped me get my first stable SSTO, might work in your case too.
  18. I'm not saying Ion engines are not worth using. I'm saying I can't get to a height where they can be useful. If I will miraculously come up with a design that can get me to at least 80 000 m on Eve I will totally use 2-4 Ion engines to circularize since all fuel will probably be used up at that point even with LV-Ns.
  19. I tried that on Kerbin. Unfortunately, there is a huge power gap between even LV-Ns and ions and unless you have more than 8 ion engines, the contribution while in atmosphere will be less than 100 delta v for a lot of weight which could've otherwise been fuel. Using more than 8 ion engines is even less productive due to their mass. So far - the only part of ascent where ion engines have proven themselves to be useful is the last few hundred delta v when you circularize your orbit. Maybe a thousand. That's still 1500 dv short of a feasible SSTO.
  20. A lot of questions about this recently. If it's a jet plane - you probably placed a lot of air intakes in the front. Move them as far back as possible, at high speeds Drag is the most common reason for instability. New players get stuck with this a lot since there is no marker or indication that Drag has its own center which depends on air intake placement.
  21. It's a medium-sized cargo carrier actually. I use it for assembling stations and stuff in Kerbin orbit. I was going to make a larger version for Laythe trips but just can't stop using this thing. I mean, it even wiggles its advanced canard "antennae" when ASAS is on...
  22. I aerobraked with my periapsis at 75 000m, was enough to keep me in Eve SOI. After that a couple of passes at 78 000m helped reduce the orbit. The wiki says 72 500m, so I guess around 73 000m will be good enough.
  23. Thank you. Yeah... 6000 delta v is the best I got from my TWR 1.0-1.7 SSTO designs without using jet engines for that pesky ascent through the thick parts of the atmosphere. Will keep trying though.
  24. I happen to have a good list of all the things that can go wrong with an SSTO in the Tutorials section. http://forum.kerbalspaceprogram.com/showthread.php/33681-Jods-list-of-aerodynamics-issues In short - you will need to balance 4 centers instead of the usual 2. Mass, Lift, Drag and Thrust. +There is fuel tank balancing. -Thrust is the easiest and should be aligned to be exactly on the same horizontal line as mass just like for any other spacecraft. -Lift is more or less easy, the Center of Lift should be somewhere close to Center of Mass, usually on the same horizontal line, and it is easy to check its balance when taking off the runway - if you nose up and loop it is too far front, if you dive then it is too far back. -Drag is absurdly vague, there is no marker for where it is, but keep things symmetrical and place more low drag(0.1) parts in front and more high drag(0.3) parts in the back and you should be fine. Most common high drag parts are air intakes, most common low drag parts are aerospikes. -Fuel tanks should be around the center of mass or symmetrically distributed along the craft so that when they are empty Center of Mass would not shift, preferably at all. Also as a side-note - if you use jet engines use ram air intakes, the radial ones don't work well for some reason.
  25. Same thing happened to my orbital tug a while ago. I still have to tug around that little rockomax fuel tank module because nothing I do seems to unjam the damn Sr. clampotron. Good thing I had RCS ports on it, otherwise the tug would be uncontrollable. I can push the Undock button all day but nothing happens. It happened when I rammed the 2 Sr. clampotrons at 0.3 m/s. Since then I approach carefully and nothing else jammed yet.
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