Wanderfound

Something a little different: Craft file at https://www.dropbox.com/s/bki39ohbj7vr40i/Kerbodyne%20Jetlift.craft?dl=0

FAR rocketry at the smaller end of the scale: Craft file at https://www.dropbox.com/s/bki39ohbj7vr40i/Kerbodyne%20Jetlift.craft?dl=0

Kerbodyne Jetlift. Craft file at https://www.dropbox.com/s/bki39ohbj7vr40i/Kerbodyne%20Jetlift.craft?dl=0 - - - Updated - - - My favourite arch...

With airbrakes, basically just keep them open until you start to feel them negatively affecting the stability of the ship, then close them. Keeping them balanced and set well behind CoM will help (although the further from CoM, the more they restrict your ability to manoeuvre). Are you using proper airbrakes, or just flaps/spoilers, or both? You want your control authority set so that the plane will always do as you tell it, but won't flip out of control when you apply full stick. Ideally, full stick should take the plane close to its g and stability limits, then stably hold it there. Finding the exact settings for that is a matter of fiddly trial and error. Dynamic Deflection helps (it allows you to have effective deflections in thin air without them being overpowered in thick air), but so do the assorted stability-inducing build tricks. Position of lifting surfaces, control surface settings, etc. Stalling is only an issue at low speed; once you're comfortably supersonic, you can get away with huge AoA so long as you remain stable. Forward surfaces (canards etc) stall more easily than rear surfaces. There are two responses to this: set the max deflection on forward surfaces lower than the rear ones, and/or use negative AoA settings on the forward surfaces. This will also improve stability at high AoA, but if overdone and not balanced against powerful rear surfaces, may make it harder to keep the nose up when you want to. You need to mess around with the settings to get a feel for them. Build a basic mid-wing plane with canards and a tailplane. Set it up with various patterns: deflections high rear / low forward and vice versa, positive AoA vs negative etc. Take them for short test flights and see what happens. Run a static analysis at a speed that requires a decent AoA for level flight; maybe Mach 3 at 20,000m. Watch the control surfaces as you do so; the AoA settings will kick in and move the surfaces to match the level flight AoA. This should help you get an understanding of what they're doing. You can also test spoilers and flaps like this.

Highly recommended. Makes high-speed manoeuvring much safer.

Are you using Dynamic Deflection?

To avoid wobbles, don't push, pull: :

Most heat transfer is by conduction; the nacelles have a lot of engines attached to them, and the only conductive escape for that heat is forward to the LF tank. Adding some small fins to the nacelle as radiators may help. It also helps to lose the ascent heat before reentry: do a few orbits to enjoy the view before you come back down. Did you keep your airbrakes open once the air thickened up? If not, why? Usually I just rely on the Kerbal Flight Data temperature warnings. If it's yellow I try to climb gently, if its red I try to climb sharply. And then I don't come back down until the reported temperature is decreasing, and try to come down at a rate such that it stays out of the red. Once you have vertical control, you have temperature control. If it gets too hot, just fly higher. Most of my "overshot KSC" incidents are due to unexpectedly needing to stay at altitude for cooling purposes.

Also workable: fins that act as fins on the way up, but flip sideways (max-deflection spoilers, fins placed in pairs so the deflections oppose) to act as airbrakes on the way down. That usually requires a nose-first reentry, but an inline cockpit fronted with a heatshield/decoupler/nosecone (nosecone for ascent, heatshield for descent) works well for that.

Mass at the bottom, drag at the top. A few high-up goo pods often work well as reentry fins. But: why bring it back at all? Go EVA, collect the data, reenter with just the pod.

Take it higher; climb to 18,000m or so then put it into a shallow dive. Level off once you've gained speed, and climb as slow as the heat limits can take from there.

As per usual. What's the problem? The Kangaroo ​does require Kerbal Joint Reinforcement, though.

I'm hoping for an F1 circuit and a dirt track with banked corners and jumps. Hafta wait and see, though.

A demonstration of a nosespike at work:

Revised version of the single engine ship; will happily and stably hold 15g all day long. The twin engine beastie doesn't handle perfectly at low speed (over-controlled, tends to pitch wobble) but is almost as good as the single-engine one in supersonic turns. With both, the main problem is in running wide (as much a matter of piloting judgement as anything else, but reducing wing loading should also help) and exploding through speed-induced overheating (about Mach 3 for both). No idea of how to improve the latter, though. Craft file at https://www.dropbox.com/s/us7yewbdp5y7nmd/Kerboracer%20MG.craft?dl=0

Sorry about the buttshots; it's hard to manage 15g at 100m in anything other than chase view. Here's the single-engine raceplane (craft file at https://www.dropbox.com/s/r4jdh62ipy9czdk/Kerboracer.craft?dl=0): And this is the twin-engine version (craft file at https://www.dropbox.com/s/fx3q0f3vhw70wbt/Zoomie.craft?dl=0): At the moment, the single-engine ship is the faster of the two on the track; it turns a little tighter, and has enough punch to hit Mach 3 at the end of the long straights (and more speed is useless, as it'll explode from overheating at around Mach 3.1...). The twin-engine version probably has more potential, but it requires more care to fly; it's easy to overshoot a turn. - - - Updated - - - Another rocketry example: gimbal is king. Craft file at https://www.dropbox.com/s/fmis3ep4bu48uu8/Krokoduck.craft?dl=0

Might come in handy: Craft file at https://www.dropbox.com/s/9vptzzhq8knsoaj/Kerbodyne%20Hiflyer.craft?dl=0

That sort of tailless no-canard delta often has pitch trouble; your only pitch controls are the elevons up back, they're close to CoM and there's a lot of nose to lift. But you can usually make them work by cranking up the maximum deflection on the elevators. If you've already maxed out the elevator deflection and still can't lift the nose, then you either need to add canards or shift the wings forwards a bit. If you spend some time fine-tuning the tail drag, you can probably cut a fair bit off it. Shift the vertical stabiliser back and forward by the smallest possible amounts; find its lowest drag position. Then do the same with the Thuds, the wings, the intakes and any other widgets you have in the region. Then do it all again because any changes you made late in the process will disturb the positions set early in the process... You can see where the big wiggle in the yellow line is, and how it relates to the peak of the cross-section curve. Smooth out the curves in the green line and the yellow line will flatten out. Pulling your wings forwards a bit might help with both your drag and your pitch problems.

I noticed it while building; the effect is there even with parts attached. The debug voxels look okay, but the area rule curves say otherwise, with or without a part attached behind.

The drag profiles of the cockpits appear to be a bit off; the green line from the FAR analysis in the pictures below is supposed to be tracing the cross-sectional area of the cockpit. It implies that the cockpits are vanishing about halfway along their visual length (except for the K-10, which appears to be totally absent from the wind). The "gap" that this leaves in the cross section causes huge transonic drag, right at the nose of the ship. Flip city.

I'd be inclined to do it with three classes defined by engine: basic jet only, turbojet only, anything goes. The limiting factors are mostly heat tolerance and cornering ability, so a big multi-engine ship doesn't have much advantage over a smaller nimbler one. The ability to melt your cockpit half a second earlier just isn't that useful... I'm only speaking from a FAR point of view, though. You should probably find a stock flyer to check the course in standard aero before setting anything in stone.

Or this: Craft file at https://www.dropbox.com/s/1m53ww9y81bh5qm/Krokoduck%20SP.craft?dl=0

I've got a new toy for the racetrack: Craft file at https://www.dropbox.com/s/fx3q0f3vhw70wbt/Zoomie.craft?dl=0 (all stock parts, Kerbpaint paintjob optional, designed for use with Dynamic Deflection) I use it on these racetracks: How do I make it faster? The problem isn't raw speed; even a single turbojet plane can rapidly accelerate to cockpit-melting speed at 200m. The problem is getting around the track more quickly. Acceleration helps, but we've already got ample power and a fairly slick airframe (wave drag of 0.57 from a 3.8 cross section on the twin-engine ship). It's mostly about cornering; how do I get the tightest, fastest turns? The single-engine one can safely hold the g-meter pegged at anything up to Mach 2; the twin-engine delta is tending to peak at 10g or so, but I can probably increase that by upping the deflection on the canards a bit. Even with the g-meter pegged, the corners on the track tend to hold me to a little above Mach 1 if I don't want to run wide, with bursts of Mach 2-3 at the ends of the straights. What else? I'm open to all suggestions, no matter how left-field. Airbrake-driven handbrake turns have been tried, but tend to lead to rapid explosive disassembly when deployed at Mach 2 in thick air. I'm open to rocketry, but keep in mind that ships will reliably overheat shortly after hitting Mach 3 at this altitude (the gates must be passed below 200m).

The turn arrows look good; nice job. Have you tried Black Krag Reverse yet? It seems to be the hardest of the four routes. BTW, I've got a new toy for the racetrack: Craft file at https://www.dropbox.com/s/fx3q0f3vhw70wbt/Zoomie.craft?dl=0 All stock parts, Kerbpaint paintjob optional.

A new one: Craft file at https://www.dropbox.com/s/5qzix822rswwlqo/Kerbobee.craft?dl=0