AeroGav

I built something similar a while back, but took it off KerbalX after 1.05 because the low heat tolerance of the wings. Also, the "Stretch" version of my "Voodoo Ray" can go to Duna and make it back into orbit, though i added Vernier engines Also, inspired by your craft I made a SSTO of the Vulture - But anyway, back to the Martian-3. BTW, my version of Martian-3 grew a bit https://www.dropbox.com/s/xcddg7dfuusx9on/Martian-4.craft?dl=0 Has a full mining setup . Action group 1 for nukes, action group 3 to open service bay and extend drill. Action group 5 deploys radiator and starts drill. 2k delta V is enough to capture Duna yes? A bit less prone to melting but really those fat-455 wings are a bad move, would rather a pair of big S instead. Also got 3 vernier lift engines on the RCS system - press the translate up button just before touchdown, and you can get quite a low landing speed on duna. 5 landing gears for stability.

I'd given up on airliner wing SSTOs with recent changes to heating, but I did manage to make your airplane into one in 1.31 with 1400dV or so. Tried adding strakes ahead of the main wing, with the idea of providing some heat protection. Not sure if that's doing anything or not (other than spoiling the looks !) It's lost a lot of its nimble handling though, now flies like an Airbus ! Action group 1 - nose up trim Action group 2 - neutral trim Action group 3 - nose down trim Action group 4 - nukes toggle Action group 5 - afterburner cancel Fly with prograde on , navball in surface mode. Nose down trim during speedrun, at 700m/s activate nukes. Neutral trim above 750 m/s. When heat bars appear, go to nose up trim. https://www.dropbox.com/s/8bgg5svqp4kx74n/Vulture - Flying Wing.craft?dl=0

Ages ago, I did an experiment - attached a number of different wing segments to an airplane, flew it with "display aero data in action menus" turned on, to verify that all wing parts have same lift/drag. I then used mechjeb to fly an airplane at different angles of attack, and found the best l/d values. It's easy enough to get a "whole craft" l/d value by enabling aero data gui in the alt f12 menu, and use that to tune Mechjeb. In subsonic flight (less than 0.6 mach) you can get very high l/d ratios from the wing parts (over 40) at low AoA, but the parasite drag from the fuselage limits the total craft value to less than half that.

Lift/Drag ratio is the same with all wings. Lift / Mass ratio is the same for all wings except the basic swept wing. The Swept Wing, and aerodynamic parts where 100% of the surface area is control surface, have half as much lift as they should for their mass. Lift/Drag ratio is best about 2 degrees at low speed (below 150m/s), is optimal at about 3 degrees at 200 m/s, then at supersonic speed 5 degrees is best. Jettisoning a wing can temporarily give you a speed boost but since lift is reduced, drag performance may worsen in the medium term as you end up at a lower altitude which increases drag from non-lifting fuselage parts. If course, if you are below optimal AoA then it could actually help to correct things by reducing lift. Of course, you are also shedding dry mass by doing this as well. I suspect the optimal amount of wing shedding is somewhere between our designs. Carrying the whole wing to orbit , like mine is too much, because it's extra dry mass and there isn't much fuselage drag to be reduced by gaining altitude sooner due to lift (fuselage is already tiny, compared to wing). However, I think going from a FAT 455 to a single Big S wing strake is too drastic. Don't think i'll build any more entries however, i don't like these edge-of-the-seat flights !

Yeah I see what you mean. The hard bit is getting up to 10km , after that you've actually got pretty good TWR, but the question is , is there enough fuel left? More wings means less drag (because you can fly lower aoa and get up to greater altitude sooner), but more mass needs to be accelerated to orbital velocity. I got frustrated with the initial takeoff part, and eventually just installed Mechjeb to give me the precise control of AoA you need to make that marginal low altitude flight work. My entry is 15.689 tons for a command chair to orbit, though it does keep hold of its wings. The only parts discarded are the wheels. I suppose if 100% recycling is your thing, you could make a re-usable dolly to carry it on the ground. https://www.dropbox.com/s/gj692nirssnd46v/zimtstern.craft?dl=0

Anyone tried flying my "Voodoo Ray" beyond low orbit yet - it was designed as a mid tech crew trainer...

Well, my 50% payload fraction lifter certainly had a lot of wings, and was NERV powered ! ...and this thing.. Has a lot of wings, which add mass, but they enable us to get a 4.2 to 1 lift/drag ratio. This means it can continue to gain altitude and accelerate with only 0.3 to 1 power to weight ratio (it has a lot fuel, enough to ssto to Mun surface and back). Wings are lighter than nervs, so its generally better to add wings than extra nervs

Good job ! I started down that path when someone in career mode with well developed rocket tech started moving into aircrafts, and wondered if you could do anything with Panthers and Nervs https://kerbalx.com/AeroGav/Stretch-Ray

Wings are your friends here, I'd personally not want to drop them unless i'm within 90% of orbital velocity. Those airliner wings don't like heat though, not good for over mach 5. I'd be more inclined to keep the wings to orbit and ditch the underslung nervs and their tanks when empty, past a certain point - over mach 5 or so, orbital freefall is supporting most of your weight, so you will be able to maintain altitude over 30km even with a small angle of attack. So drag will be very low. BTW , is there a rule against rover wheels? If not i'd take a drive to the mountains behind KSC and launch myself off the top at 5km, when the NERVs will already perform pretty good due to height.

On a normal PC with a discrete GPU, the difference would be very small - under 5 percent, only time i really see a big difference is on level load times (more relevant to first person shooter games and the like) when the extra bandwidth copying textures for the level from main ram into video ram made a huge difference. Especially in games where you die a lot. However, once it's running there's not much in it. CPUs care more about latency more than bandwidth - how fast that stick is - rather than having two slots on separate circuits that it can communicate with simultaneously. For CPU stuff, 99% of the time program data is in the CPU's own cache memory. Occasionally, it needs to reference a byte or two that weren't brought into the cache ahead of time. But it's only a byte or two, not bulk transfers. The time taken to access that first byte is critical because the whole cpu is waiting, but not how quickly a 1mb block can be copied over. IF you've got integrated graphics however, dual channel ram (having each slot on its own circuit, and having a memory module in each slot) in some cases will double graphics performance. That is because almost everything a graphics chip does involves copying from a texture into video memory, with multiple passes over every pixel on the screen as lighting, shadows and other effects are applied. Discrete graphics chips have their own ram, operating at very high speed, soldered directly onto the motherboard, but integrated graphics are bottlenecked by the capability of the system memory,

Many of the problems with KSP are to do with SAS and the poorly calibrated joystick support, that makes analog control just about impossible. I learned to work around it and make passively stable spaceplanes that have thrust in line with centre of mass, and zero cg shift as fuel burns off. I fine adjust the angle of the tailplane/canards in the SPH so it is trimmed to hold the angle of attack it needs for the flight to orbit with no input from the pilot. There's some trim flaps that deploy via action group for other flight conditions (something to force the nose down for airbreathing speed run), and the control authority has been tweaked down so that you get just enough ability to make corrections with all-or-nothing keyboard control, and no more than that. Of course, don't expect these airplanes to win any aerobatic contest. They probably make an Airbus A380 look nimble. https://kerbalx.com/AeroGav/Voodoo-Ray No incidence or built in trim. Designed to be flown with pitch trim. No CG shifts in flight, thrust axis is in line with centre of mass. Does suffer a bit with adverse yaw, could do with more stabilizer area... but space planes don't turn, they just hold 90 deg due east. https://kerbalx.com/AeroGav/Stretch-Ray Improved version with built in wing incidence and trim flaps. Fly with SAS set to prograde hold in surface mode. Action group 1 trims the nose up a few degrees, action group 2 trims the nose neutral, action group 3 trims it down slightly. @Scarecrow what's with all the Voodoo craft today ?!!

Well, it's not so different from the Ray in that it likes you to milk the air breathers and the Ray flies best if you don't let the nose get too far away from prograde, but for the reason that it hasn't got enough rocket thrust to overcome drag if you do, rather than it going into a flat spin if over-pitched !

I see you discovered the automatic roll correction system. If the pilot lands one wing low, excess mass is shed on the affected side to help restore balance. BTW, someone from the environmental protection agency called, seemed quite agitated and was dressed in this very outlandish white "bee suit" suit-and-mask garb, any ideas what that's about? Can't be anything to do with the old airfield, I just finished a headcount of the seal colony there and the numbers are up quite a bit. When I fly the Ray I normally milk it up to 7km or so on jet power staying below 240 m/s, then level off, give it a burst from el NERVs until properly supersonic (440 or so) then cancel nukes, and climb up to 14km or so, level off if not already at 750 m/s, then once 750 m/s is reached, stage the nukes on and concentrate on keeping the nose about 5 degrees above prograde. Ignore any porpoising and don't freak out if it starts descending at any point, just maintain nose 5 degrees over prograde for optimal lift/drag and it'll accelerate to orbit while trending upward. Then again. your method might use more fuel but gets to space faster so what do i know? Also it seems the Ray's part count isn't too kind on your Mac ! Regarding the Widowmaker, the nose cone catches a lot of air at high angles of attack and causes stability to go negative, i guess the fact CoM is so far aft gives it a long lever arm to torque the craft. I'll have to watch the second half of your video again to see when you staged, i found if i try going much over 1350 at 17km the nose melts off and it pretty much doesn't want to accelerate any more in any case.

I have many interplanetary SSTO on my KerbalX page, though none are an exact match for your spec. There's a small self refuelling SSTO (mk1, five seat) called Starsailor and a big liner called Lusitania. The Stretch Kerboliner is a large mining passenger craft but it was built some time ago , i don't know if it still works. My rule of thumb is one RAPIER and one Panther per 50 tons or so of launch mass, and one nuke per 20 tons. If you follow low drag design principles and fly the right profile, that is sufficient engine to get to orbit with low drag/gravity losses. Once in orbit, I check the remaining delta V readout on Kerbal engineer. You want 2k delta V leftover in low kerbin orbit to be able to comfortably land on Minmus and refuel. If you got 3k or more, you can straight shot Duna and brim the tanks there. If it is able to get to orbit comfortably on the relatively low number of engines i am suggesting, but does not have enough delta v left, then there is just too much payload for a plane of that size, either make it larger or reduce the number of passenger cabins. Since it is able to get to space easily on that number of engines, efficiency is probably already close to optimum. I wrote a tutorial covering drag reduction and flight profiles amongst other things -

I can't do it ! Eventually learned how to survive takeoff, but never figured out how to reach orbit before fuel runs out. My first successful takeoff , was also my best orbital shot - 71km AP and 14km PE. After that I tried another dozen times, burning off the nose cone, flipping out at hypersonic velocity, or just lamely running out of fuel again, but all of these subsequent attempts had a lower PE so were further from successful circularisation. Well, I wanted to say this from a position of strength, having passed the challenge , but I would say that a true test pilot can adapt to any aircraft they find themselves in, even one with radically different characteristics. So here's my own challenge airplane, the Voodoo Ray. No twin Whiplash for you - one Panther is all you get. 1000kn of Vector ? Now try with 120kn of NERV. Gimbal , what's that? Oxidizer ? That's for cleaning toilets or dyeing your hair blonde, right? https://kerbalx.com/AeroGav/Voodoo-Ray Action Group 1 - Toggle nuke Bronze Certification Reach orbit, land anywhere on Kerbin without killing the pilot. Silver Certification More than 80% recovery value from landing fairly close to KSC and not damaging the airplane much or meet bronze award conditions with no use of SAS below 40km or meet bronze award conditions without reading instructions Gold Certification Land on the Runway with no damage or destroy a KSC building on landing, without killing the pilot. or land on the KSC peninsula from orbit, without restarting the jet engine (dead stick approach !).

A vertical surface can never control roll or pitch, it can only generate Yaw, because it can only deflect airflow left or right. You need horizontal surfaces that lift up or push down parts of the plane. They either lift the nose up or push the tail down to control pitch, or they lift one wing up and push the other down, to generate roll. Real airplanes do have winglets but they are passive (no actively steering surfaces). They reduce wingtip vortexes which cause drag and make turbulence for airplanes landing after them, but KSP does not simulate wingtip vortexes. The thing is, in gliding flight, you have no engine power to maintain forward velocity, so you counteract drag by flying "downhill". During re-entry you want to lose speed , and stay out of the thicker parts of the atmosphere until your speed is reasonable. But by the time you are subsonic (under 240 m/s) you need to maintain speed at a reasonable value. So, on the final 1000m altitude down to 100m altitude, set pitch so the nose is pointing no more than 3 degrees above prograde. On the final 50m above ground level, start increasing pitch to reduce the rate of descent to something your landing gear can handle. You will no longer be getting enough velocity from flying "downhill" and your speed will start to decrease, but hopefully you will have enough airspeed in the bank to maintain this low descent rate all the way to touchdown, without stalling. Honestly, you might be best off hand flying the actual landing. Mechjeb is great for precise control on ascent for max delta V, but in a rapidly changing situation like this it's gonna be tough. Try to get used to thinking about "angle of attack" and not "pitch". "Angle of attack" is the difference between where the nose is pointing and where the plane is actually going. When angle of attack increases, lift increases, enabling you to fly more slowly. However most of the increase in lift is from 0-10 degrees. After 10 degrees there is not much more lift to be had, and at 30 degrees the wing stalls and lift actually starts decreasing. Drag increases rapidly with increasing AoA, and goes up even faster after you stall. I suspect you were telling mechjeb to maintain a flight path that didn't maintain your airspeed. You got very slow, and the nose might have been pointing at close to zero pitch, but the airplane was dropping like a brick with the prograde vector in a 20 degree descent. Thus your angle of attack was +20, with high drag, and a high rate of descent needed to stop airspeed falling even further. As a result you landed at high rate of descent which broke the wings. Note, this can be a problem when you attach the landing gear to the wings of heavy airplanes in KSP. Sometimes it is best to attach them to the body, use the rotate tool to make them point straight down, then use the offset tool to space them outwards. Also known as a T tail Use the offset tool to move them to the top of the tail fin. Because the tail fin is swept, this means it can be as far back as possible (far from CoM, so plenty of leverage) and also means it is well clear of engine exhaust. I think he can keep his canards though, as he is not having problem with excessively forward CG. Also remember the rear mounted tail gets the nose up by pushing down, so if you're having a problem with excessive descent rate on touchdown it's probably better to get the pitch you need from lifting the nose "up", if possible. @GoSlash27 I do use tail elevators on my current designs as well though. Normal pitch control is via the canards at the front, but during the speedrun I "deploy" the rear elevators with an action group, which lifts the tail slightly , pushing the nose down a couple of degrees. This stops the plane climbing above flameout altitude till i've wrung every bit of speed i can from the air breathers. Then reset to neutral trim for the NERV-powered part of the climb.

But, What is CG? - Centre of Gravity = same thing as Centre of Mass = The Yellow ball in the VAB I like that method. There are still some problems with the control layout. Why have you got a tail fin at the front, attached to the roof of the cockpit? Vertical surfaces passively increase stability when they are behind CoM, even without being actively steered, aero forces on the fin push the tail back into line. Conversely, aero surfaces ahead of CoM make stability worse, when they catch the air they will try to push the nose further out of line. Get rid of it !! Also, why have you got a pair of vertically orientated fins on the wingtips? They are close to your centre of mass, so they have little leverage to control yaw. Get rid of them, or if you want extra wingspan or roll authority, use the rotate tool to turn them horizontal. The blue ball seems to be a long way behind the yellow, so the good news is it is very stable in pitch, but it looks like it will be very nose heavy. It will be very hard to hold the nose up on this design. The only surfaces that can do so are the elevons you attached to the trailing edge of the wing, as they are behind your centre of mass, they can get the nose up by pushing the tail down, so the nose pivots up like a see-saw. But, they are pretty close to the centre of mass so won't be very effective as there is not much leverage. Try attaching a pair of canards either side of the cockpit, use the offset tool to slide them as far forward as possible. Remember, stability is not the same thing as control. Stability comes first, then you add enough control to make the plane do what you want. The plane will glide more efficiently when the distance between yellow and blue balls is not so huge, but obviously you still want to be stable. You can safely use designs where the blue ball is less far aft when the centre of mass doesn't shift much in your craft. For example, imagine a space plane with heavy engines right at the back and a light cockpit up front. It is balanced by fuel and cargo bays up front, but when returning from orbit empty, the centre of mass will move way aft and become aerodynamically unstable. A good basic layout has cargo bays right in the middle over centre of mass, so it doesn't change Centre of mass whether loaded or not, and distributes fuel ahead and behind the cargo bay in such a way that fuel burnoff does not change balance either. Then you arrange the components that are always there - engines, cockpits , crew cabins - to make the plane balance when empty. Your design is pretty good already from what i can tell - you have 6 tons of nerv engines fairly close to CoM, and these are balanced by a 4 ton cockpit which is lighter than the nervs, but has more leverage due to being further away from it.

At high angle of attack yaw stability decreases, that is why fighters like F-15 have twin tails. The forward fuselage is catching a lot more of the air than it will in normal flight. The main tail fin is not very far behind your CoM, so it doesn't have much leverage - it won't be as effective. Also, you have two sets of AV-R8 winglets mounted with 4 way radial symmetry ahead of the main wing. You need to reattach these immediately with mirror symmetry if you change nothing else about your design - the vertically mounted winglets on the top and bottom will be ahead of your craft's CG, and will actually be working to reduce yaw stability not increase it. BTW, those two rows of winglets are weird. For controlling pitch, you want the forward pair as far forward as possible so they have leverage. For controlling roll, you'd be better off attaching them to the wingtips so they are far outboard. Have you gone into game settings and enabled "Advanced tweakables"? You should right click on each surface and disable the control functions you don't want. Eg. The tail fins should not attempt to control roll, only yaw etc. Finally, try coming in at a less extreme re-entry angle. In KSP aerodynamics, 25 degrees is quite extreme and i don't think your craft has the agility to hold that. There is no real need to. Try setting 10 degrees instead, and burn retrograde to intersect the ground a little earlier (like the desert) because drag will be less. If it starts looking like you're overshooting, raise the pitch a few degrees more for extra drag. If it starts undershooting, lower the nose closer to 5 degrees , which is the best glide angle. BTW your method of attaching engines looks like it will create huge drag. KSP aerodynamics hates it when you mate parts of differing diameter together without using an adapter. It also hates empty attachment nodes, if you are not using all the points on an engine mount you need to put a cone. Performance is a different subject though, this is about loss of control. I wrote more on drag here - BTW, when you graduate from Spaceplane on a stick type launchers, here's a type of two stage to orbit jet boosted design to consider - https://kerbalx.com/AeroGav/Learstar-A2 It's actually based on the stock VAB Learstar, I converted it to jet boosters instead of rocket - stock version -

Yeah, that craft was built more than a year ago, quite a few things have been revised since then. Some parts have got draggier, others less draggy, aerodynamic heating is now much more sensitive to placement of the part (bad news for pointy cockpits). In terms of Matt Lowne's craft in the picture, the pointy cockpit would have to go, and the solar panels are now draggy even when stowed, and should be moved inside a service bay (or have an RTG in service bay). I did put a guide in the Tutorials section on making SSTOs, it's only one game version out of date ! Keep the Mk2 parts to a bare minimum, they are so awful for drag. Ideally, only the cargo bay should be mk2. Mk1 can even be used for cockpit and crew cabins provided there's a service bay, fuel tank or intake ahead of them to absorb heat. Definitely do not keep fuel in mk2 parts, not worth it at all. The best thing to put fuel in is a Big S strake , failing that big S wing, failing that, use a mk1 size tank. You need to use a lot of wing area and angle the wings up at their attachment point to the fuselage to make a mk2 design viable. This enables you to fly with the nose on prograde lock to minimise drag from the fuselage parts. I have some vaguely similar craft on KerbalX that are fairly recent if you want to study them - https://kerbalx.com/AeroGav/Lamb That nose cone is now a poor choice, i should replace with shock cone. Has a clamp o tron and cargo bay. https://kerbalx.com/AeroGav/Coimbra-PA-X-LR This one has a rapier clipped into a Panther, the two engines complement each other well (one is good at low speed, the other high speed). Can reach Minmus but a return from Duna would need a refuel. The reaction wheels are now somewhat high drag, though not compared to all the mk2 cabins it has ! My most recent SSTO avoids most of these faults and combines a decent amount of delta v as well as crew capability. But it's a mk1. Also as a "barebones" craft, it lacks lift thrusters for landing offworld. https://kerbalx.com/AeroGav/MK1-Griffon-Deep-Space-Crew-Shuttle

Damn that sucks. So it's the worst plane you've tested then, and won't be getting another shot against anything? Despite it's size, it does better in turns lasting over 3 seconds than anything else i downloaded. But yes, it did suffer a spate of losses when i first built it, getting shot down in the head on pass before the two aircraft ever got into gun range. Thought i'd solved that, but clearly not. Ironically, it's ability to turn at high g without dropping below 100 m/s makes it good at avoiding missiles normally. Unlike other challenges, where you know how much delta v your craft has etc., it can always fail to perform on the day. This is why i prefer a "league" system of matchups. Maybe I should conduct those - a series of quick 1v1s and the one topping the league table for "points" is the best fighter?

I fought my Kryfoon against it, it acted like a bomber and flew away, and used the superior speed of its whiplash engines to stay exactly 2km ahead. The two aircraft engaged at extreme gun range, my Kryfoon only has twin vulcans , if it had 3 the outcome might have been different, but it was never quite able to make any parts on the Monstron overheat. Surprisingly, the Kryfoon was able to withstand the barrage at extreme range. However, when my Kryfoon ran out of 20mm, the AI pilot switched to missiles and started flying away from the Monstron, trying to get optimal missile range. Bad idea to show your six to a faster plane, the Monstron started overhauling the Kryfoon and when the range got down to 1.5km or so , was able to kill it with the Goalkeepers. I 'm not sure how to configure the AI pilot, my Kryfoon never shoots off anything like its full complement of missiles, perhaps i should have played with the ripple fire setting. When it looses a fight, its usually because it's too busy dodging missiles to win the dogfight.

That's some pretty neat flying ! Some thoughts Given that 2.5m parts have much lower drag than mk3, why wrap the payload in a CRG100 bay? Just have the 2.5m ore tanks naked to the wind on the final stage i notice on the second stage there is a single Vector surrounded by Darts on each booster. This is often well over 20 km before being dropped - given how poor Vector vacuum ISP is, surely it is better to drop all vectors by a lower altitude? similarly, can the nukes be staged in any earlier. By 10km they are close to full vacuum ISP, in fact by 5km they have more ISP than chemical engines, so might as well turn them on ? tricoupler is the lowest drag - i notice you use a 1 - way adapter at the bottom of some stacks, with a load of radially attached engines. I dont know if this is as good from a drag point of view but it does pack the engines more densely within the 2.5m radius. I suppose by this point drag is relatively unimportant compared with getting the right TWR for each stage, so your design might still be the best..

Lots of very long and thin mk1 sized rockets out there, but do people know that 2.5m fuel tanks have the best capacity / drag ratio of all ? Maybe an orange tank based lifter, with a 2.5m tricoupler and some aerospikes/vectors ?

That rocket has impressive length, I must say.

Maybe if someone tried combining tech from my vessel with this guy's approach to delivering an orange tank - https://kerbalx.com/SpaceAgeDreamer/RX-MK2V7R2 before flight - after flight props to @spaceagedreamer ! - or a smaller version of the above, carrying xenon tanks to orbit. That's almost practical, since you can't mine xenon..