AeroGav

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Everything posted by AeroGav

  1. Get friend zoned by Soolin. Then try my luck with Jenna. If Cally looses that 80s poodle perm, maybe I'll even creep around her for a bit. Then teleport over to the next Liberator ship and see how it goes with the clones of the above crew members. Repeat 9999 times.
  2. The tank i used in my screenshot above was in the middle of a stack, it had the shock cone at the front and a cockpit behind it. You could reduce the drag of the tank by mounting the wings at 5 degrees incidence angle and flying the fuselage on prograde, but that's not a fair comparison as you wont fly on prograde hold for much of the airbreathing part of the flight, you'll probably be at some negative fuselage aoa. More wings = less drag during the nerv part of the flight, less wings = less drag & faster acceleration on airbreathers since nervs are so heavy and underpowered, the main driver of my designs is how it flies in the hypersonic part of the flight. Getting through mach 1 is the next most important part, and you can improve this by fitting less wings than i normally do, but i don't like to do that because it makes the nerv part so much worse. You can still easily break mach 1 even with a flying wing design. That said, my designs are criticised for taking a long time to reach 1500 m/s in the speedrun, with less wings and drag, and flying lower where there is more intake air and thrust, i imagine your ssto can get to 1500 quickly, even on a single jet engine.
  3. ??? 0.44 drag on a big S strake, lift rating of 1 Last time i checked, all wing parts have same lift to drag ratio, so a pair of big S wings (lift rating 10 for the pair ) would be 4.40 kn drag at the speed , altitude and angle of attack in that screenshot. Equivalent to 3.18 mk1 tanks, not 7. Given how heavy NERVs are, I'm inclined to make all my fuel tanks Big S parts to make this part of the ascent easier (get out of the lower atmosphere faster, once you pitch up from the speed run). This does slow down the air breathing part of the climb, when you can't just fly higher because your engines need air to breathe. On the other hand it makes landing speeds so slow you're guaranteed to survive no matter where where you land and enables some of the dumb stunts i've done (mountain lake to minmus challenge on the Puffin, or takeoff/land from the VAB roof while fully fuelled)
  4. Don't trust the red arrows, they are not to scale. Use ALT+f12 > physics > aerodynamics and tick the "show aero data in action menus" checkbox. I did a quick test - Those strakes on the back of the main wing have 0.44 drag, if you used 4 of them to have same capacity as the fuselage tank , you'd get 1.76 drag, which is slightly higher than the mk1 tank. To an extent, you can compensate for this by busting mach 1 at a higher altitude, since the larger wings enable you to fly at low angle of attack in thinner air, but beyond a certain point thinner air makes engine thrust fall away faster than drag, so yes, you get better airbreathing performance with small wings. However, when you are on NERV power, the lift from the larger wings quickly takes you up in to the thinner air above 30km, where fuselage drag and heat are greatly reduced. I find myself applying nose down input at 20km for the speedrun but once i've lit the nukes and pitch for optimum lift/drag, it zooms upstairs , levels off and starts to gain speed quickly.
  5. No, mk2 has about 2 and a half to three times of a mk1 part of the same length. This is terrible for fuel tanks as they contain no more fuel than a mk1 part of the same length. For passengers, they are not so bad as you get twice as many kerbals per module, but the kerbals to drag ratio is still worse, especially given that you'll now need mk2 to mk1 adapters at front and back of stack, which contain oxidizer tanks you are not using.
  6. probably because of the wing incidence angle allows flying on prograde lock, so the engine parts and the empty nodes are now at zero angle of attack, reducing their drag, allowing you to get away with not having them. I'd still keep them personally, it's not like you're going to notice the dry mass reduction with the weight of all those nervs on such a vessel
  7. Intakes don't work properly if facing backwards in fact - as you get faster, they normally bring in more air, but facing the wrong way, they intake less which is bad news as that's just when engine demand starts to go up. I do normally still put cones on the back of all my engines because busting mach 1 is the hardest part, the less jet engines you need for that, the more delta v or payload fraction you can bring as those things are heavy. However, the difference in drag between aerodynamic nose cone vs shock cone are very small compared with the drag the mk3 fuselage parts are creating. This is the area you should focus on in my opinion. Ways to get the fuselage drag down 1. add incidence to the lifting surfaces, as IronMaiden has done, so the craft will fly on prograde. 5 degrees is optimal angle of attack for lifting surfaces at supersonic/hypersonic speed - which coincidentally is what happens when you hold SHIFT-S during part attachment. 2. try not to use any fuselage fuel tanks. Seriously , liquid fuellers don't need them. If you swap all your wing parts over for big S ones (including your vertical stabilizer), you probably have enough capacity to get to orbit without them. Check out my Andromeda freighter, which can put an Orange tank in orbit. https://kerbalx.com/AeroGav/Andromeda In practice, you will probably still need some kind of fuselage "trim tank" to get the CoM where you want it to be, or to make sure it doesn't shift around as the fuel burns off. But , it might not need to be a full mk3 one. Maybe just a mk1 lf tank up front, behind the intake cone? 3. That mk3 "Space Shuttle" engine mounting plate can be very draggy if you don't use it right. Your craft notes say it was based off my "Lusitania" ship.. hopefully you copied the attachment method that thing used ? Remember folks, it has a center 2.5m part attachment node in the middle of the three "vector engine" mounts, and you get an eye watering flat plate drag penalty if you don't put something on this. I usually fit a 2.5m tri-adapter on there, for three more mk1 sized engines. I clip that adapter inside so it looks less like the airplane is suffering a prolapse, then offset the engines horizontally so it looks like they are attached to the sides of the rear fuselage. I can't download your ship as I don't have "making history" x-pac. Two other changes i'd probably make if it were mine - i'd swap half the rapier for panther, this arrangement gives slightly more thrust for busting mach 1, weighs 2 tons less, at the cost of a negligible decrease in top speed in level flight, airbreathing mode. There's not much in it though. I'd probably want some other cockpit arrangement, for "quality of life" if nothing else. That mk3 cockpit gets so hot as it is at the front. The nose cones etc on its front node don't shield much of it from heating as they are much smaller diameter part. You could fit some kind of mk1 or mk2 inline cockpit, via a series of mk3 to whatever size adapters (would do double duty as your trim tank). Or put a mk1 inline cockpit at the front of the cargo bay, and offset it upwards so only the bubble canopy pokes out the top. That way you can still fly it from the in cockpit view, but the cockpit is still shielded from the drag and heat. This is the method i used in "Monstrosity 225L"
  8. Also, the air mattress has a plastic skin. Plastic is made of carbon and hydrogen, both of which are very rare on the moon.
  9. I've often wondered what a lunar habitat might be like if it started growing itself with in situ harvested resources. Lunar soil and rock appears to consist mostly of metal oxides and silicates. So, probably one of the very first things a colony with aspirations of becoming self supporting can do, is start excavating additional habitable volume for itself, and constructing bricks and furniture items out of carved stone. In 16% gravity, they would not be particularly bothersome to handle. In terms of processed/man made materials, smelting the regolith to separate the metals from oxygen (which is also useful..) is centuries old tech. However, the moon appears to have very little in the way of lighter elements such as carbon, hydrogen or nitrogen, these only being found in ice deposits in permanently shaded craters. On such a base then, everything possible would be constructed of stone, metal , glass or porcelain, these being relatively cheap due to the materials being locally available. On the other hand, plastics, wood, and textiles, the cheapest available materials on Earth, would be luxury items on the moon, having to be imported at great expense. So your bed frame would be stone or metal. The mattress would be sprung, and the pillows stuffed with wire wool rather than foam or feathers. Only the outermost cover would be textile. Perhaps only wealthy colonists would use sheets or duvets. Your living room might be quite spacious, carved into a cliff face, with quite generous glass windows looking out over the moonscape. Again, if you're wealthy, you'll have an armchair with a textile outer cover.. otherwise make do with stone or metal. A kiln probably isn't difficult, so expect to have plenty of porcelain dining ware. The real big ticket luxury item is however your entertainment system. A PC can do the job of games console, tv, radio, and workstation, and the bulkiest , heaviest components like the case and heatsinks, cooling fans, could be made locally. PCBs are medium tech and can be refurbished on site with surprisingly modest equipment in case of most failures, but actual manufacture of the PCBs is harder, and the integrated circuits they contain would have to come from earth. Fortunately they are tiny and light. It is still likely that new motherboards/graphics cards would ship from Earth. PCs have an advantage in being modular, but perhaps small form factor (Mini ITX ?) would save shipping cost. All of this pales by comparison with whatever you've got to use for the display however. There seems no way around this - large LCD panels are hard to manufacture yet are also heavy, fragile and bulky. Your monitor or TV is probably worth more than the rest of your apartment put together !
  10. OPT parts have horrible drag, worse than mk2. I think the authors of the mod calculated drag based on volume of the fuselage section, so as they have more internal volume than mk2 drag is scaled up accordingly. This seems to be how squad calculated drag on the stock parts - mk2 parts have more volume than mk1, so they gave them more drag. Except that in real life, that wing body blending reduces drag at transonic/supersonic speed (at the cost of higher weight), and in real life, the wing/body blending can be used to store a lot of extra fuel, whereas in game, mk2 parts contain no more fuel than mk1 of the same length. There is a wonderful mod called Kerbal Wind Tunnel that will tell you if your design can break the sound barrier without even leaving the SPH. It also shows top speed at each altitude, so you can work out the optimal altitude to attempt to get supersonic at.
  11. I'd say its all about lift drag ratio. You want to get the best exchange rate possible, that means maintain the nose 5 degrees above wherever the prograde marker is pointing. When you deviate a couple of degrees off this 5 degree angle of attack your lift to drag ratio goes to hell. Looks like you're able to make this work by getting into a 30 degree zoom climb after reaching 1200m/s at 10km when the Whiplash is still making a lot of power - by the time your upward momentum has run out, you've gained enough horizontal orbital velocity. My designs are intended for a level flight speedrun at 17km, then start the nukes, and once the jet power is dying away about 1350 or so, ease the nose up so it's 5 degrees above prograde and keep it there. If your lift drag ratio is good enough it should work. To do that in the above craft i'd want 3 times the wing area and switch to an inline mk1 cockpit. Pointy cockpits get much hotter, and with smaller wings relative to your weight, your craft goes lower in the atmosphere for any given speed when means more friction heating.
  12. This craft of mine was built for the mountain lake landing challenge. https://kerbalx.com/AeroGav/Puffin Seaplanes are tricky, change one thing and there is no guarantee the craft will lift off the water again. It can comfortably land on Minmus starting from a standing start on Kerbin, and i used the cheat menu to put in orbit of Laythe and verify that after de-orbit burn, it can land on and take off from the ocean with nearly full tanks, and then fly to Laythe orbit with 2500 dV left once in orbit. So if you'd rather not mod this airplane, build something with a Claw that can refuel it in Kerbin orbit, for the trip to Jool, and then put another low grav IRSU lander in jool system to gas up for the return leg... the irsu lander could touchdown on a low grav world like pol or bop. The IRSU lander can be tiny because this thing doesn't take much gas. Something like 10T of liquid fuel to completely fill it. Doesn't use oxidizer, except for the ventral vernier thruster.
  13. I ended up overshooting and climbing too high on my initial burn, reaching an AP of 65km at 1900 m/s - this thing makes a lot of lift ! So i cut the engines and let it coast down on prograde. Restarted engines at 50km, things start getting hot below 40km, end up pulling several Gs from lift at 37km to level off. Overheat bars are shrinking again so i start pitching down, trying to delay my broaching 50km as long as i could. If going above 70km before the record attempt is against the spirit of the challenge, i feel like i could use some high thrust LFO engine for the final fling, when its no longer possible to stop the ship climbing and you just want to get as much velocity as you can before you bust 50k
  14. I don't have time tonight to design anything specifically for the challenge, but I wanted to see what a recent airplane of mine would do. I give you the Korten Fledermaus flying wing - https://kerbalx.com/AeroGav/korten-fledermaus Still had plenty of fuel left but those Type B nose cones like to melt. They are fairly important, they keep the NERVs attached to the wing. Doesn't accelerate much once these pop.
  15. I don't think you're the first person to say my designs take too long to reach orbit, so i had a go at making a more powerful version. I must admit, I really like cruising through the upper atmosphere, because it's the only time you get to see it (too high for airplanes, too low for satellites) so that's why i build them like i do. I have a savegame from the point where my spaceplane is ready to stage in the NERV engines so i can skip straight to this part of the flight. Having reached orbit with as much delta V as possible, i then usually revert or just leave the guys floating up there forever, and go design another spaceplane. Even though i got the delta V to go some place, i don't particularly enjoy that part of the game - plotting manuver nodes and waiting around. Anyway, instead of trying to do it with as little as possible (one Whiplash, two LVN), this has twice as many jet engines and one extra LV-N. On my first attempt I got to MECO in ten minutes, second time i screwed up and climbed too steep, had to dive down again for the speedrun , which is why the screenshot shows MECO at 11 minutes. That's about half the time of the original design. Although the launch mass is higher due to the extra engines, it doesn't use much, or any, more fuel to get into orbit. Once again, this is a RETROGRADE orbit. Going East West like a sane person would leave a lot more delta v, save time and not get so hot. https://kerbalx.com/AeroGav/Snoopy-SSTO In terms of the NERV or not to NERV debate, I agree that at this particular tech level it makes less sense especially if you're only going to low orbit in an east-west direction. NERVs really shine when you're doing Panther / NERV because the top speed of the Panther is low and the rocket mode burn to get to orbit is a long one. This tech level is important i think because whilst NERV take a few science points, they can be done on a level 2 R&D building, whereas the Whiplash/Aerospike node is tier 8 and needs the Max level R&D. Getting the cash for that upgrade is the longest grind in career mode ! Paradoxically, NERVs also work well at higher tech level when you've got BIg S wings to hold all your fuel in. This gives a liquid fuel only design a big advantage in drag reduction over something that needs large LFO tanks. For example, check out my flying wing - https://kerbalx.com/AeroGav/korten-fledermaus I think this is more your kind of ship MK, about 7 minutes to MECO - still plenty of Delta V left too !
  16. Trouble is if mass goes up, you get more downforce via gravity but surely the amount of force needed to get it moving, make it stop and make it turn go up by just as much ? Though of course i'm assuming kerbal physics work like real physics which is a big if ! THe OP's video just looks like those small rovemate tyres are made of wood. Either that he's gone into friction override and set all four wheels to zero. (Maybe the low weight confuses the Auto friction control preset) turn the back wheels to max friction and give the fronts a lower value, see how that goes.
  17. I did win a payload mass fraction challenge with a nuclear engine, liquid fuel only ship. However the things you have to optimise in a nuclear ssto are completely different to a high twr rocket one . The nuclear ssto has a much lower fuel fraction , needs high lift and low drag. The rocket ssto needs high fuel fraction and low dry mass. So long as it can take off and get supersonic the rocket one doesn't have to worry about lift or drag too much, it quickly blasts out of the atmosphere. The retrograde orbit and the amount of payload - crew cabin for 6 seats and a cargo bay - make this a fairly demanding job for an ssto at this tech level. Tough to do it without building an enormous craft whose fuel tanks/engines dwarf the actual payload.
  18. I have built many liquid fuel only SSTOs, the problem with yours is that it has far too much fuselage drag and far too little lift (wing area). With Whiplash engines i prefer to get my speedrun about 17km in level flight. After that raise the nose gently so it's pointing just 5 degrees above prograde after starting the nukes. With nukes you always have low TWR because they are heavy and weak. Your craft can still gain energy so long as the goodness of your lift to drag ratio exceeds the badness of your TWR, to use simple language. Optimum lift drag ratio in high speed flight is when the nose is 5 degrees above prograde, so that is what you should aim for once the nukes are on. In KSP about 80% of the drag is from fuselage parts. The ideal for a liquid, nuclear spaceplane is to put all your fuel in Big S wing parts, but as that tech is not available to you, I'd say go with mk1 liquid fuel tanks instead. Mk2 parts look nice and have good heat tolerance, but they make twice as much drag as mk1 parts with the same fuel capacity. They only really make sense for kerbal containing bits, since they give twice as many seats per part which offsets the higher drag. And for the love of god, give it more wing area. Like four or five times as much. I put this together really quickly, trying to base it off your design as much as poss. https://www.dropbox.com/s/qpnu93jw84yhhgz/snouty.craft?dl=0 This ran out of fuel just before circularising ! So i redesigned it with 2 more mk1 liquid tanks. Whilst i also converted the crew bits to mk1 size, it may not have been the best move on account of how hot they all got. https://www.dropbox.com/s/01t94h8kja37fp8/snouty2.craft?dl=0 We made it though
  19. I'm not much good at rovers, but it generally looks like an oversteer problem, as in the same thing that affects auto racing. Airplane landing gears in KSP suffer that too. You need to go into friction control override and make sure the front wheels have less grip than the rear, so they loose traction first. That stops the back end drifting out. The other thing seems to be that those wheels are giving you too little friction overall for the mass of the vehicle, under Duna gravity. It slides sideways for ages without stopping like it is on sheet ice. You might need beefier wheels. Building a fast and safe rover is very difficult in this game however, so i'm not sure how good a rover can be.
  20. I studied a bit of biochemistry a while back, so from that angle : Heat - human metabolism is only about 20% efficient converting the chemical energy into mechanical work. The other 80% ends up as heat. So, when i'm on my bike I can do a 1000 watt sprint (just under one and a half horsepower) for a few seconds. During that time I'm generating 4000w of heat. My aerobically sustainable output is 220W. That's a mere 900w of space heater boiling my blood. Fat is our most energy dense fuel source, and gram for gram it stores almost as much energy as petrol/diesel products. Unfortunately our bodies have trouble burning it quickly. Much over 100w and and the energy starts to come from Carbohydrate instead. Why is this ? Well, it probably doesn't help that fat is not water soluble, and our metabolic reactions are things that happen to stuff thats dissolved in our body fluids, for the most part. Second, carbohydrates are made into fats by stripping off their oxygen molecules. Carbohydrates have a roughly equal number of oxygen , hydrogen and carbon atoms in them. But oxygen is in the air all around you, so get rid of them to improve the density of your fuel. Except that oxygen atoms have a stronger affinity for electrons that carbon and hydrogen, resulting in that end of the molecule becoming "polarised" with a slight negative charge. This makes it easier for enzymes to latch onto and react with them, and allows them to dissolve in water. Third reason, we're not a migratory species. So what about carbohydrates as a fuel source ? Well, they only give 4 calories per gram unlike fat which does 9 calories. In practice, they are even less dense, because they are hygroscopic (attract water). Your body only stores about a kilogram of carbohydrate (enough to last about 90 minutes) but that kilogram attracts 3 or more kg of water weight. Still more energy dense than batteries though. So, our super human could be engineered to not store energy in the form of fat at all, and store all of their excess calories as glycogen. Or we could somehow invent a way to make fat burn as fast as glycogen, then happy days. The other thing you could do is jack up our body temperature. This will make heat dissipation more efficient, and should also increase the rate of the chemical reactions in our body. However you'd have to redesign all our enzymes and proteins to not break down in the heat. There's no such thing as a free lunch either. Enzymes that are more stable at higher temps tend to suck at lower ones. These super soldiers would have to maintain this higher body temperature permanently or else suffer hypothermia. Nature already does this - birds have a higher body temperature than mammals. So to summarise - super soldier with no fat storage, all excess calories stored as glycogen, and higher body temperature would do much better than a normal human if asked to run as far as possible in 24 hours with a heavy backpack. However, owing to their less efficient energy storage, and higher basal metabolic rate to maintain the higher core temp, they'd do terrible at surviving a famine.
  21. Anybody made one? I'm ok with the SSTO part, but have never really made a flying wing. This is about as close as i ever got, but it still has some naughty vertical surfaces. Gotta have that yaw stability. Also, think it got hit rather badly with the ugly stick. It shifts though. Looks to have quite a bit of delta V (as you'd expect, given there's no payload beyond Jeb) https://kerbalx.com/AeroGav/korten-fledermaus
  22. You've done a decent job putting the engines amidships so it should stay balanced. Like that you're using Big S wings as tailplanes to keep part count down. The big key to making something so huge is coming up with a layout that doesn't cause it to break apart through an overstressed joint. As for the "what's the point" ? Argument, you could say the same about my largest creation. It's pretty small compared with that thing (we could call its payload 120 tons if we allow 0.5 tons per kerbal) but still fairly ludicrous. Why would you ever need to transport 225 Kerbals to orbit in one go ? Coming back to the game after some time out, the surprising thing is how nice it flies (compared to some of my recent experimental creations as i relearn the game). Yeah you can snap the wings off pulling more than 4g (like an airliner) but it tracks really straight.https://kerbalx.com/AeroGav/Monstrosity-225L
  23. I haven't played Kerbal for a year, so this is a bit tricky. Anyway, this is probably the tiniest liquid fuel only entry you're going to get. 8 tons, two junos, one nerv, 540 units of liquid fuel is all we need. Bill even gets a proper capsule ! https://www.dropbox.com/s/fegeqs11z7p8f0c/jUNOVATOR3.craft?dl=0
  24. Press ALT F12 in flight to bring up the console menu, go to physics, aero section, then tick the box to show aero data in action menus. The mk2 body parts have less than a 10th of the lift of a wing part and more than 10x the drag. It's not right but i guess they can't buff it because it could break existing crafts. Note that all this drag up front does actually torque the nose up, particularly at high angles of attack. This is why you are having to use "huge wings at the back". The stock centre of lift indicator does not take into account aero forces from nonwing parts properly, so for a lot of aircraft with a long neck and an AFT CoM, it can be way wrong. There is a mod called CorrectCoL which gives a more accurate indication - on the last airplane i worked on, the stock indicator showed the blue ball well behind the yellow CoM marker, they were only touching by their edges. Switch to CorrectCoL and it turns out CoL and CoM were in the same place.