AeroGav

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About AeroGav

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  1. The main thing I learned between my first two crash landings and the second two that were without damage, was that you need to have the wings level with respect to the slope on the ground at touchdown. On my third landing attempt, the ground was sloping left to right so i had to bank 15 degrees to right to make both main gears touch down at same time. If the mains dont touch down together, then the ground contact sets up a rolling torque that's propertional to your vertical descent rate on touchdown and as you can see from the first one, it can be pretty severe. It's quite rare for things to go wrong once the wheels are solidly on the ground - i don't remember it happening, but a bounced landing, when you are still above flying speed, can get hairy.
  2. That's a nice GIF. The blue indicator is sorta reliable if all surfaces are at the same AoA (except for the fact it doesn't take account aero forces acting on non wing parts, which is why you need CorrectCoL) but you can get into trouble when adding incidence to wings. What you're effectively doing there is adding some nose up trim to the elevators. At zero AoA, CoL is ahead of CoM, and the plane will pitch up, but because the main wing is already starting out from a higher AoA than the elevators, it gains lift more slowly as the AoA increases. This causes CoL to move aft as AoA increases and the plane will tend to settle at its trimmed AoA. Again , CorrectCoL makes this easier to visualize, you can bring up a graph of stability vs AoA, you want stability to increase as AoA rises. These days I build my planes to fly "hands off" at a small positive AoA with no control input, so it doesn't just dive into the ground if you let go of the stick. ps. "Centre of PRessure" , "Centre of Lift" etc. people get tied in knots over these terms. We talk of "Lift" and "Drag" but isn't that a false dichotomy? In reality aerodynamic forces act on the structure, and we call the component acting in opposition to the direction of travel "Drag" and the forces that are perpendicular to the direction of travel "Lift", but really it's the same thing. Especially with respect to the way the physics engine simulates this stuff.
  3. Yeah she's just going to have to catch up on Netflix for a few years while another transfer window comes around. I was thinking of sending a probe core, claw, mk1 fuel tank with a spark upper stage and SRB lower. Given that this aircraft has a dry mass of about 13-14 tons, one mk1 fuel tank worth of fuel should get the whole thing back to Kerbin from Duna orbit?
  4. He's got huge canards on (i was going to name that vessel Dumbo because it looks like a flying elephant) and this is less of a problem for takeoff - they takeoff by lifting the nose up, so the fact gears are well aft of cg is not a big deal. Landing on rough terrain though it can pitch you forward when the main gears hit, on Duna that can cause a fatal tumble. If your pitch controls are via tail only, having gears aft of CG can prevent takeoff. They raise the nose by pushing the tail down, and if your main gears are underneath the elevons rather than at the CG, the elevons would have to push the gear below ground level to make the nose go up. Probably, you won't succeed at that. If you do, then you might find yourself having to pay for a new runway.
  5. They can be done but career mode with standard difficulty settings doesn't really reward re-use - it's mostly a grind to get the cash to max upgrade the science building. I've done a few airplane only career modes as a self imposed challenge, and i've also done custom difficulty where the "Funds Penalties" (ie. building upgrade cost) and "Funds Rewards" (cash payouts for contract completion) were both reduced by 1/3. This meant cost for vessel parts was actually a bigger expense than building upgrades, which made re-usable craft actually worth bothering with. My best Panther SSTO is this one , which can do return trips to the Mun, and could give you a return trip from the surface of Duna with a bit of in-orbit refuelling - https://kerbalx.com/AeroGav/Stretch-Ray However, it also has a NERV engine, which is hardly a low tech part. If you've only got Panthers and Terriers, I'd recommend something like this to deliver a Kerbin SOI exploration vehicle to orbit. https://kerbalx.com/AeroGav/Aero-Tug-1 (here it is hauling a science lab, but obviously you'd just replace that with an exploration vessel for payload) Once the exploration vessel is in orbit , dock panther/terrier spaceplanes with it to exchange crew/transfer science and refuel the thing for another trip to Mun and Minmus. You'll soon have enough science for NERV, and then you can really start going places. Share your craft file on here we can help diagnose it.
  6. I don't know why you'd need a rocket engine to take off, you can build a juno powered plane that circumnavigates kerbin that can take off under its own power. Most of what you are lifting here is rocket fuel for the rocket engine. The only reason to build something like this is if you're trying to make a spaceplane, suborbital plane or are using the rocket to boost you to altitudes over 17km. The limits of what you can take off with tends to be that when your plane is too heavy, the gear breaks before you get enough lift to take off. Having a rocket engine won't help with that, you'll just reach the speed where the landing gear comes apart quicker. However, a properly designed and flown aircraft does not need anywhere like that much fuel. If you're going long distance, remember to fly high and keep speed below 240m/s, AoA below 5 degrees. However there is also the issue of human patience... are you really going to spend 2 hours flying to the opposite side of kerbin for one measly contract?
  7. I guess I wanted to try limiting "drag losses" - stay out of transonic region - till we'd climbed a bit, and also i wanted to see a bit more of the landscape before leaving for good. But it probably would have been better to just gun it. I knew i wasn't coming home at that point anyway. Now, how would you go about rescuing Val from Duna orbit?
  8. With Mun gravity, it has over 1:1 TWR on just two nukes even when full of fuel. Obviously by the time you reach the Mun most of the fuel will be gone, also if you are able to reduce the number of rapiers (from 7 to ?????) when you will be lighter still.
  9. Hmm well for some reason this one turned out to be a bit unstable still, fully loaded. I wanted to try another engine config as the previous was sluggish accelerating That's the mk3 engine mount with 3 1.25m nodes, and one centrally placed 2.5m node. I use a 2.5m to 1.25m adapter on the middle node to give me four engine attach points, but i attach the engines one at a time and use RCS build aid and the offset tool to make them symmetrical It does accelerate well, due to the good low speed power of the panther. It also gets our CG even further forward, because we don't have the mk3 to 2.5m adapter pushing our engines back. But, the CoL is now too far aft with the CoM so far fwd, you can't pull more than 5 degrees of AoA it's so nose heavy. Also, loosing that fuel tankage at the back of the ship means we need to cut some from the front or CG shifts yet again as fuel burns off.
  10. This is what i did https://www.dropbox.com/s/cees80iu2dhi3dt/SSTO 5.craft?dl=0 Got rid of the four radial rapiers. The diamond shaped wing allows me to put the heavy nukes on the wing tips, a bit further forward. = less dry mass at the back I changed the forward rocket fuel tanks for a small liquid fuel one, and built a tail fin out of strakes that hold more liquid fuel = more of our fuel mass at the rear There is much less difference between empty and full. Of course, it is now much less powerful. The old one, with your cones on, was very simple to fly - take off , AoA 5 degrees, try not to melt, space ! With cargo it might really test your patience. Rear engine designs look much cooler imo, but only work on a mining/passenger ship where you got some heavy stuff you can put at the front that will still be there on landing. Really hard with cargo ships that have to fly back empty.
  11. You've done it correctly, you can offset the cones as far inside the engine as you want (so they can't be seen) or rotate them so the flat base is still visible like you have done. The important thing is that the node is closed , and that the collider that checks to see if the engine exhaust is occluded doesn't run into any obstructions. Because your cone ends before the exhaust stream starts, you still get thrust. I did some tests and found that pointy end facing forwards or backwards makes no difference, but sideways would be bad. So cone facing with 0 degrees aoa with respect to pro or retro. You can now maybe think about reducing the amount of engines. They are very heavy (2 tons) and reduce your delta v by increasing dry mass. Also, when i flew your ship, i got my AP out of the atmosphere with 4000 oxidizer still left over. Might want to reduce the oxidizer tankage a bit for some LF you can use for the interplanetary mission... one prob though, CorrectCoL shows your craft to be unstable when fuel tanks are empty. Too much engine mass at the back !
  12. That's awesome. I usually smash up the facilities on the way back, but you'd found a way to do it on departure !
  13. I just flew mine to Duna, but after landing in two biomes only had enough fuel to get back to Duna orbit. In career mode you'd want to find a way to refuel this aircraft in low kerbin orbit so you can go home again, as well as properly tour Duna. Junior clamp o tron on the nose, have two airplanes meet in orbit and transfer the fuel from one to the other? I love flying on Duna though, amazing views.
  14. Well, I got round to flying a Duna mission on mine. Beefed up the landing gear, added two Vernors, and 3 oscar Bs. Each landing used about 10 units of oxidizer. Some stunning vistas, but sadly we only had enough delta V to land at a couple places then fly to duna orbit. I used a 130km parking orbit on kerbin which isn't efficient ( direct burn from launch is best if you take a few tries to get launch timing right). But perhaps we're expecting too much from this level of tech to make a single stage round trip. What i would do, is find some way to refuel this plane so it can do Duna properly - it has enough oxidizer for 6 horizontal landings, with only a little extra fuel it could have done all that and come home. Easiest way is probably to put a junior clamp o tron on the nose and have two of these airplanes meet in low orbit, have one give its fuel to the other. Can always wear a small nose cone to cover the clamp o tron on the way up, to save drag and stop it melting, then decouple it. It can fly around on kerbin on dry power, so if you're ambitious you'd brim the tanks in orbit and send it to Laythe - could probably visit every island.
  15. Stock aero doesn't care much about shape, but it cares a lot about how parts are attached, so we really need you to link the craft file so we can examine it properly. Four rapiers is a lot for a small plane like that, and that's a huge amount of oxidizer too , so i'm worried there might be something in the way stuff is attached making excess drag. The golden rule - every stack must start and end with something streamlined (intake, cockpit , nose cone, or jet engine*) When two attach nodes meet, they must always be of the same diameter. eg. sticking a 1.25m engine on the back of a mk3 fuselage (3m node) bad ! use a proper mk3 to 1.25m adapter between them. Open nodes are bad too. The rapiers and nukes have attach nodes on the back end which you are not using, these cause drag because it is a 1.25m stack ending abruptly with no "cone". Stick 1.25m cones on the back of these engines then offset them forwards to clip inside the engine for minimum drag, this reduces the drag of engines with attach nodes like rapiers and (all rocket engines) down to that of jet engines that don't have one, eg. whiplash. Download this subassembly for example of streamlined mk3 mount https://kerbalx.com/AeroGav/Streamlined-6-Nuke-Mk3-engine-mount