capi3101

Finally back home after an extended stay at my in-laws, with their vastly superior KSP-playing box. Trying to think about what all was accomplished... The Vulture flight to refuel Munport was a relative success; she delivered her payload, flew back to New Horizons to offload her excess fuel and then landed successfully at the KSC Runway. The actual landing was rough - one I probably wouldn't have been able to pull out on my home box, but was able to do at my in-laws. The mission did leave New Horizons a bit short on fuel so I launched another Vulture mission to refuel the station. Turned out to be a good thing I did that... See, because shortly after the Vulture arrived at Mun, my Mun Buggy finally arrived at the Minmusport space station. Jeb and the crew of Free Bird 7, docked to the station at the time, transferred to the Buggy for a ground science excursion and flag-planting mission. That went off without a hitch; the Buggy returned to Minmusport, the science collected was processed in the lab (bringing the station's data buffer to full) and then loaded aboard Free Bird for the journey back to Kerbin. Owing to the presence of Lagercie and Albert (a pair of tourists) aboard Minmusport in need of transport back to Kerbin, Kacella was left on the station with Diissa and Bob (who were running the science lab). Thus prepared, Free Bird made the trek back to Kerbin. Free Bird's aerobreaking went well, but she ran out of gas after making a stable circularization burn around Kerbin while aligning planes for docking at New Horizons (I've long ago decided to keep Free Bird in space until I can get the opportunity to swap out the craft's landing gears for ones that are more substantial, so the crew was headed back there to swap for an updated Raven 7 design for the re-entry). Fortunately, I had that Vulture up to resupply the station; change of mission - the Vulture was sent to re-supply Free Bird instead. The resupply went well and Free Bird finally made it back to New Horizons, transferred the crew and science to the waiting Raven, and landed successfully back at KSC. Made a tonne of bux for the varying missions - two of the returning Free Bird crew were Minmus rescue contracts worth about √450,000 between them (plus they came back after having orbited Kerbin and planted flags on Minmus - two new crewmen automatically at two stars upon their return). The money and science earned allowed me to finally unlock Mk3 parts and upgrade the R&D facility to Level 3, while leaving me with around √650000. Another √800k will give me a fully upgraded KSC facility... Meanwhile, that Vulture is still in orbit - she burned up her remaining fuel trying to deorbit. Forgot to re-set its control point to its probe core after docking. So, facepalm there. Also was able to combine a Kerbin rescue and tourist contract for √60k between them; the landing didn't go smoothly. Insufficient chutes and landing in the mountains west of KSC. Lost most of the craft, so the profit margin was not as high as I'd hoped for those two missions. Still, √10k is better than nothing. I've still got a crew en route to Minmus due to arrive soon for flag planting; they'll haul everybody still at Minmus back home with them. Got plans to send three crew members to Mun to plant flags as well; I've got a new tourist contract to Minmus at this point, and long term plans to send most of the KSC staff on a trip into Kerbol's orbit to get them their respective three-star ratings. I'm thinking of updating the Vulture design for that one; it really is a pretty solid design overall.

Apologies for an "is it plugged-in" type of response; the graph data and stats default to blank before you "mash go" for the first time. Have you actually pushed the button on the graphs page that says "Sweep AoA" or "Sweep Mach", and/or have you pushed the button on the derivatives page that says "Calculate Derivatives"? If not, try that first. Then if you still have problems, come back and say so.

Got a chance to play KSP last night on my mother-in-law's computer, whose specs are vastly superior to my own box at home. Came to the conclusion that most of the problems I now have with flying planes in KSP is the direct result of my sucky box; landed on the Island runway and flew back to KSP successfully, with the only part breaking off being a Commontron 16 I was using as an airspike on the front of my plane - and that only happened because I accidentally rammed the thing into the side of a hangar wall while fiddling around prior to the flight back. KSP really looks nice on a box that can run it - switching back here in a few days is going to be hard... Came to the determination that I needed to permanently scrap the Condor 7 design. Also sent a Vulture 7 on a mission to refuel the Munport space station; refueling the craft at New Horizons took most of the station's available fuel reserve, so using Vultures to resupply Munport may not be a viable option. Definitely need to get mining operations set up on Mun as soon as I possibly can. Meantime, I've got Minmus operations due to start in nine hours.

My designs tend to go either Whiplash/rocket or RAPIER; I don't generally put both on the same plane. 13 tonnes per engine if you go with RAPIERs, 15 tonnes per Whiplash. For the rocket phase, I'd recommend you plan for 1800 m/s of delta-V; that should be sufficient to get you into orbit, let you fiddle around a bit (say if you wanted to send the plane on to some kind of orbital rendezvous), and de-orbit. If you don't want to add fuel, go for a higher efficiency engine; Thuds work okay. I've also had luck with Aerospikes if you can handle their lack of gimbal. Your ascent profile is sound, and the mods I would suggest have already been suggested to you - RCS Build Aid to let you see how your CoM is going to shift in flight (thereby letting you know if your plane is going to become more stable or more maneuverable as you go), and Intake Build Aid to easily side-step a known bug in how Intake Air is distributed to air-breathing engines thereby vastly improving their performance. If you only got one of these two, go with RCS Build Aid; it's really the KER of spaceplanes. Of course, there's always the option of updating your aero model from stock to FAR. That's a whole other experience there, but FAR does give you a whole slew of data about your planes - the challenge being learning how to interpret that data, find potential problems and correct them. Trying to think if there's any other mods I use for planes...I do use B9 Procedural Wings just because I like being able to make precise tweaks to my plane parts, but I wouldn't consider it an essential mod.

Well, I like having a place to start. Most of the time, my design process for the fin goes like this: 1) Carefully determine what I think the area of the fin should be. 2) Carefully determine the length of the root and the span based on that area and the shape I want it to have. 3) Build the tail to those carefully determined specifications. 4) Throw out the whole damn thing because it looks like dreck and exchange it for some random thing that may or may not work on the first go. 3/2, eh? I can probably handle that...

What is a good aspect ratio for the vertical stabilizer, anyways? (Yes, I know - it. depends. on. the. craft. Just in general, though, what do you guys typically shoot for?)

True - you can increase the area by making either the root length or the height longer. Poor choice of words on my part in my prior post.

Needed things to do while I awaited the arrival of a Mun Buggy lander at Minmusport. After checking my personnel logs, I determined that three of the remaining four ground crew at KSC needed to practice flag planting on Minmus. All four personnel - Berris, Ludine, Pepe and Valberta - were loaded into the newly redesigned Raven 7a design and sent up to the New Horizons space station, where Straight Flush was still berthed. Ludine was given formal command of Straight Flush for the journey to Minmusport accompanied by Valberta and Pepe, with Berris (the craft's former commander) having already earned her two-star designation joining Bill at New Horizons for training for their upcoming journey into Kerbolar orbit. The flight of the Raven was completely uneventful; the replacement of the landing gear for larger gears did eliminate the threat of tail strike, a problem that the earlier design exhibited on several occasions. In anticipation of the return journeys of Straight Flush and Free Bird (Jeb's craft already at Minmusport), I also launched a fully loaded fuel module en route to Minmusport. Due to differences in trajectories, the fuel module should arrive a full two days ahead of Straight Flush. Meantime, all these shenanigans have killed the time I needed to fill in - the Mun Buggy is now eleven hours from its Minmus encounter. Plan is to dock the module at Minmusport, transfer most of the remaining fuel from the transfer stage to Free Bird, then send the Buggy down with a full crew of six (Jeb, Miglas, Burlong, Kacella, Malfurt and Diissa) to Minmus's surface, leaving Lagercie (a tourist - whose itinerary did not include a landing on Minmus) on the station for the duration of the excursion. Upon its return, an evaluation of Free Bird's fuel status will be made; if the craft can make it back to Kerbin, it'll depart at that point. If not, it'll await the arrival of the fuel module. Jeb will be returning with Miglas, Burlong, Lagercie, Kacella and Malfurt; Diissa will remain to assist Bob in Minmusport's research lab until after Straight Flush arrives and carries out its surface excursion. At that point, all remaining personnel at Minmus will be returned to Kerbin - and all of them should have their two-star certifications at that point. Going to be fun trying to load - what, fifteen Kerbals or so? - into a single craft for a short trip into Kerbolar orbit. I don't have Mk3 parts yet. That's probably something I should try to rectify with the upcoming Mun Buggy excursions...

Could be a combination of your planes and how you're attempting to fly them. T-Pilot395 is absolutely correct though - when you're in the air, the majority of your turning should be done with a combination of bank and pitch (aileron and elevator), not primarily with the rudder. True regardless of what aero model you're using. Can we see a screenie of what you're trying to fly?

Last night I investigated the possibility of using Free Bird 7, which was docked at the Minmusport space station with a bunch of folks awaiting the arrival of a re-usable lander capable of hauling them all down to the surface, to conduct a recently obtained rescue operation contract. Miglas's shipwreck was placed in a 7 kilometer orbit around Minmus, easily within reach of the ship/station, which were parked in a 50 kilometer orbit. Jeb swooped down, picked up Miglas (another Engineer to train) and brought him back to the surface. Miglas now joins the group that will be heading down to the surface here in a few days once the lander arrives. I also fiddled around with the idea of a KIS/KAS rover. Right now I don't have rover wheels, so those plans are delayed for the time being. Tried to come up with something to kill time between now and when that lander arrives; I was thinking of a Vulture flight to Mun to resupply the station there. Not sure if that'd be worth it or not - might get there and then have to use the very fuel I'd delivered to come home...

Do you have any RCS ports aft? If you do, I'm not seeing them. In any case, your ports are too close to the axis of rotation to generate a great deal of torque. I'd suggest a set of linear ports (the ones that only fire out in one direction) out on the wingtips, one on the dorsal and one on the ventral. Those oughta help with your roll issues. Stowing a big ASAS module or two in your cargo bay will also help to generate some torque. If you don't have it, I'd suggest getting ahold of the RCS Build Aid mod. It's useful for RCS issues in general - and for spaceplanes, the dry center of mass indicator is also a very nice feature (lets you see how much and in what direction your CoM will shift as fuel drains, thus allowing you to predict stability issues later on in your flights). I'd also recommend that when it comes to spaceplanes you should stick to linear ports (or even Vernors if you've got something particularly massive), and that you rely on pod torque for attitudinal control primarily - use RCS for translation unless you just can't turn your craft on pod torque alone (and if this is the case, it's another place where the usefulness of RCS Build Aid should be obvious).

The old rule of thumb used to be a lift coefficient of one per tonne of plane (i.e. a pair of delta wings, with a lift coefficient of two each, would safely lift four tonnes). These days I couldn't tell you with the stock model; I fly FAR and use a series of formulas to determine the size and shape of my wings (based on desired wing loading and aspect ratio). A pair of standard-sized delta wings might cut it for your design, though I have never measured the area of the stock parts so I couldn't say one way or the other. Merandix's tip of "crashing at the lip of the runway is a good indication you have too little" is actually fairly sound advice... EDIT: Hell. I'll take a stab at it anyway. So I usually shoot for a wing loading of 0.3 (about the same as a Eurofighter Typhoon) and an aspect ratio of 2:1 (roughly the same as the SR-71, Concorde and Shuttle). The formula for wing loading is L = M/A, where L is the wing loading, M is the mass of the craft and A is the wing area. Solve for A: A = M/L. Plug in values: 33 t/ 0.3 t/m^2 = 110 m^2. The formua for aspect ratio is R = B^2/A, where R is the aspect ratio, B is the span and A is the wing area. Solve for B: B = sqrt(RA). Plug in values: B = sqrt(2*110) = 14.83 m. Semispan = span / 2, so your wing semispan should be 7.42 meters, give or take. For your root length, I go with the definition of the area of a trapezoid: A = 0.5 * [r+t] * s, where A is the area, r is the root length, t is the tip length and s is the semispan. Now, we have the wing area, but that's the total wing area; for each individual wing, we want half that area, so you've got 0.5A = 0.5 * [r+t] * s. The 0.5s cancel each other out: A = [r+t]*s, and then you solve for r+t: [r+t] = A/s = 110 / 7.42 = 14.825 meters. You put the root length at half the total length of your plane, and whatever's left goes to the tip. If the tip length turns out to be longer than the root length, you need to lengthen your plane. If the tip length is zero or less, you're building a pure delta. In between those two cases your plane is a cropped delta. But like I said, I don't have knowledge of the stock parts, so I couldn't tell you what combination of parts would give you these figures. The formulas work; I can tell you that much - anything that flies in FAR should fly in stock just fine.

General rule of thumb I go with for the vertical stabilizer is to have its area somewhere between 10-12% of the total main wing area, with its root length roughly 25% the length of the main wing root (or, if I'm building a craft with a tail-plane, I want the fin to be roughly half the total area of the tail). If the configuration of a single stabilizer with those numbers gives me a fin length greater than the height of the plane (wheels down), I split it into twin tails. Take that advice for what it's worth - I usually build SSTO cargo planes, not fighters. And conversely, one that's not tall enough will give you yaw instability at high speeds (and as a result your plane will want to fly backwards). Lost a good many of my early FAR craft on account of insufficient fin...

Didn't do a whole lot this weekend; I've still got a Mun Buggy taking its sweet time getting out to Minmus, so I figured I'd take care of some pud contracts closer to home. Had a TR-2V test in orbit contract that paid √50k, so I built a little SSTO sounding rocket (the Derpnaught 7h) to do the job. Aside from it wanting to fly backwards once the engine was turned off, all went well with that mission and I was able to retrieve it for a nice little profit. Also had a Nerv test in Minmus orbit; since I'd recovered some science from when Berris had brought back her last group from Mun, I went ahead and unlocked the Nerv engine so I wouldn't have to keep a hold of that contract anymore (still keeping a hold of one for an Aerospike test on Kerbin just so I've got access to the part) and sent up a cheap little probe to go take care of that. It's now en route to Minmus and should arrive in two weeks or so. After turning down a tourist contract (was okay except that one of the tourists wanted a sun-dive; I've already got one of those in progress and I'm not confident of its chances of success), I got a contract to perform pressure test on Kerbin. The waypoints were in the vicinity of KSC and as a whole the contract paid something close to √120k, so I went for it. Designed the Pressure Cooker 7 and off I went. Plane's handling was okay; had some issues with pitch control in the trans-sonic but that's not unusual for a tail-less delta and canard configuration. Whole flight took about forty minutes RL and I retrieved the plane intact - total lost revenue for the craft was fuel, a mere √300 for a really nice profit margin. Picked up another Minmus rescue contract; since I've already got folks there (Jeb and Free Bird 7 are parked at Minmusport at the moment), I'll need to see if I can squeeze in a quick rescue mission. Possibly tonight. Fuel's a concern but not a big one since a Mun Buggy is on its way.

Yeah, that should do the trick. You've got a pretty low overall wave-drag area and good non-oscillatory dynamic stability; how does it handle with the increased fuselage length?

I imagine the cockpit and missiles aren't being voxelized properly by FAR; it'd probably explain most of the issues with the craft outright. Which mod are those parts from? Let's start with that - which mods are you using? And let's go ahead and run a U simulation with initial value of 5, and then a ß simuation also with an initial value of 5, using the 1km/Mach 1 derivatives. Post screenies of both graphs. Myself, I'd probably lengthen the fuselage a bit, but I'll defer offering that as advice for the time being.

Nice to know. OP did mention trying out a Whiplash/rocket combo - the fuel line setup would've been relevant to that configuration.

The pre-cooler acts as a combination air intake and fuel tank, but it's not going to provide you with the amount of air you'll need to keep your engines operating in air-breathing mode much more than what they're doing now. Apparently they do help with radiating away some of your engine heat. Sub-sonic is generally better for the climb to 10k; don't try to go supersonic until you're out of the soup if at all possible. 45 degrees up to 10k is perfectly fine; back in my own soup days I would occasionally manage 60-70 degrees. Best you can manage for that part of the flight, then flatten out to 10 degrees once you're at 10k and stay there until your engines kick over. If you start to see heat bars, increase to 15-20 degrees. Fix the intakes first - that's what's causing the bulk of your issues.

Taking another look at your screenies. This is not related to the initial problem but just something I'm noticing - you've got two fuel lines running from the central fuselage to the portside outboard fuel tank. I'm not seeing corresponding fuel lines on the starboard side. If you've been seeing problems with your plane wanting to yaw uncontrollably in flight, that's almost certainly why.

I've seen some mods that will give Kerbals different colors of spacesuits...I don't use any my own self but if you've got a box with the juice to handle it you might try TextureReplacer and see what that does for you.

Get up to 10k, then level out so that your prograde vector is about 10 degrees above the horizon; you still want to be going up to get out of the soup, just not as fast. Plus moar intakes - one per engine at a minimum if you can manage it. Try adding four radial intakes (a pair for each of the center engines) and see what that does for you. Add the ability to toggle air-breathing mode as an action group if you can, and keep it in air-breathing mode until you're at least up to 20k if it auto-switches. Bear in mind that if it does auto-switch and you switch back, you're liable to start seeing flame-outs. If you're not adverse to mods, you should consider adding Intake Build Aid; with it, you'll reduce the risk of asymmetric flame-out substantially, without having to go through the fuss of putting your intakes and engines on the plane in the right order (which, incidentally, could be another cause of the issues you're seeing - craft with RAPIERs install tend to switch over all at once as soon as the first one runs out of sufficient air to continue operating in air-breathing mode). For 33 tonnes in the soup, you shouldn't need more than 3 RAPIERs. The fourth helps, I suppose (nothing wrong with excess thrust), but watch that you don't overheat.

Switch to the map view. There's a little tab on the right hand side with an image of a Kerbal on that; click on it and it'll show you which Kerbals are on the craft as well as their discipline and level.

I totally agree.

When you go to take your screenies, be sure to take at least one with your wave drag pattern, one with your trans-sonic numbers, and one with the stability derivatives at the altitude and speed at which you're experiencing issues. And (of course) some profiles of the craft itself. This Dream Chaser, eh? I can see that one being a true challenge to get to fly as intended in KSP...I'll have to look at Ferram's response to your question again.

For a core, I'd suggest at a minimum a pair of Hitchhiker cans (don't have to fill them up), a quad of BZ-52s in radially symmetry set around the seam between the two Cans, each with a Structural Fuselage piece attached and a Clamp-O-Tron attached to that. Add some antennas to either end of the assembly (never hurts to have spares). On one end, put a service bay and fill it with equipment such as a probe core, batteries and so forth. Put whatever kind of manned control module you'd like on top of that (cupolas look nice if you have them), and then to the top of that add another Clamp-O-Tron. On the other end, put your science gear; you might consider a '>Geschosskopf Sci Bomb style design here; that makes for a good place to put some solar panels, incidentally. If you want, you can replace the center Girder with a piece of Structural Fuselage. And then on the bottom of that assembly, add another Clamp-O-Tron. You might consider adding Rockomax adapters to the endpieces to make the whole thing look nicer, but that's not really necessary if you're going for function over form. Notice I didn't add a lab. You could add a lab to the core easily enough - could even make it the centerpiece. You'll have to make a bigger launcher to compensate for the increased mass, of course. That oughta get you a core module that can be adapted easily for many purposes, with a sufficient number of berths for new modules or visiting spacecraft. Of course, you could do with less - check out the centerpiece of this station (under construction in this screenie; from a couple of versions ago and still one of my all-time favorite projects): That one still happens to have its Munar transfer stage attached and the "arms" are not part of the core. The core there is just a large RCS tank as the centerpiece with two cupolas on either end, four BZ-52s with Clamp-O-Trons, a quad of lights, eight OX-STAT panels and a pair of large antennas on either end. Maybe six to seven tonnes all told - and easily boosted into orbit.