Northstar1989

Mini Update: OK guys, just seeing how much I can squeeze out here before I go take care of real life... I recycled the damaged Raven Mk2, as promised, as well as some other miscellaneous (not shown) debris: Regards, Northstar

Mini-update: The Raven departs for the Mun: Also, just an FYI: I highly recommend you guys check out the Ribbon Generator (http://ribbons.cgagnier.ca/index.php) if you haven't already... As you can see, my posts now all show the ribbons I've earned in any of my saves thus far (the permanent manned Jool station was established just before a universe crash ruined an earlier save, for instance). Regards, Northstar

I know it's been a while, but I haven't forgotten about this challenge. Here are images of my refueling the Raven Mk2 at 100km, and then again at 350km (due to my own carelessness, I didn't fill the fuel tanks all the way at 100km). The spaceplane will be making another refueling stop in Munar orbit, and possibly even refueling one last time in a highly elliptical orbit around Kerbin (I'm trying to make a transfer to Duna at closest approach, so I'm going to need all the fuel I can get!) Also, as you probably noticed, I made a crew transfer at 100 km- one of the Kerbals (Bartgel Kerman) serving as crew on the fuel tanker (I utilize some manned designs as I am also simulating "relief crews" at my 350 km space station- I have a sizable infrastructure of space stations, space taxis, and a "scrapper" recycling ship already developed in my career mode save) was both more courageous and less stupid than the previous pilot of the Raven Mk2- so I swapped them. I don't know if courage has any effect on gameplay, but I do know that KSP-Interstellar, at least, rewards lower stupidity values with higher Science Point yields at the mod's science lab... Finally, here are a few images of the Raven making its transfer to the Mun- where it will be refueled by one of the two fuel tankers already sent there to refuel the Blackhawk Mk6 (I didn't know which would get a rendezvous opportunity first)- which will be refueled and sent to Duna soon. Regards, Northstar EDIT: Scratch the refueling in an elliptical orbit. The plan is to refuel again in Minmus orbit- it's very easy to set a periapsis from there that passes extremely close to Kerbin (where the Oberth Effect can be fully exploited), due to the very low orbital velocities that far out; and even on a straight burn for Duna, I think it's still a shorter burn than from Munar orbit...

Turns out the Delta-V figures WERE right. I guess I saved a lot more fuel than I thought with the huge wings and airbreathing engines (which I kept using as long as possible)... Regardless, the 'Raven Mk2' DOES have enough Delta-V to get to Duna- I'm just going to have to be, errr, a lot more careful than I thought about how I use its Delta-V to get there. That means, I may have to go for a direct re-entry when I reach Duna, as the vessel might not have enough Delta-V to establish a stable orbit around the planet when it gets there, and I *WILL* need to make best use of the Oberth effect, and possibly a Minmus gravity-assist. Finally, although it's a lot like trying to hit one bullet with another bullet, I might be wise to try and refuel the thing in a highly elliptical orbit around Kerbin or even en-route to Duna, as a direct re-entry really is a risky proposition... Anyways, here are a few images of my refueling the Raven at 350 km: Also, I captured a nice picture of the Scrapper Ship alongside the Microwave Power Station while picking up the poor Kerbal who had been stuck crammed into a tiny little workstation in the service module there for at least a couple days... Enjoy! Regards, Northstar

OK, so first of all, I set the Valkyrie on its way to the Mun: Then, I refocused on the Raven to plot its Duna transfer burn, and EEK! Somehow, in my carelessness, I managed to not top off the Raven's fuel tanks all the way (only about 3/4 of maximum Oxidizer). But more importantly, for some reason MechJeb is calculating it only has 847 Delta-V using its most efficient engine with the partial fuel load... I know that CAN'T be right, because it took it a LOT more Delta-V than that just to get it to orbit from its 34 km max cruising altitude (with jet-only power), and I didn't leave *THAT* much empty space in the fuel tanks... I'm also not aware of having installed any updates to the game or mods that should have affected the Delta-V budget- so I'm really not sure why the calculations are THAT far off... I'll let you guys know what happens from here, but for the meantime I'm just going to be sending the Raven to the Mun for another refueling stop there, until I can figure out just what's going on... Hopefully the Delta-V calculations will correct once I start burning the engines... Otherwise, I'm going to need to perform the rather difficult maneuver or setting it in a highly elliptical (comet-like) orbit around Kerbin, and then refueling it a second time THERE via fuel tanker before setting off for Duna if I want to make use of such a sub-optimal transfer window... (Duna is currently passing closest approach) Regards, Northstar

OK, so I added a bit more fuel capacity to the lowermost stage of the Heavy LFO Tanker. If it turns out not to be enough to get it to orbit, I'll just try to remember to transfer a bit of fuel down from the middle stage once I'm cruising to the edge of the atmosphere during ascent... Regardless, I finally refueled the 'Raven Mk2', and will be sending it off for Duna very soon! Also, while I was conducting the refueling operation, I noticed one of the Kerbals on board the fuel tanker (intended as additional/fresh crew for the 350 km space station) was actually both smarter and more courageous than the pilot of the Rave Mk2. So I swapped the pilot of the Raven Mk2... (I kept the Raven's co-pilot/navigator, as he was superior to the other crew member on board the fuel tanker) The new Raven pilot's name is 'Bartgel Kerman' I then proceeded to rendezvous the fuel tanker with my 350 km space station, transferred the fuel and Kerbals aboard, undocked it, redocked it directly to the Heavy Scrapper Ship (which was also docked with the 350 km space station) when I realized I had forgotten to transfer off the Monopropellant, and then after undocking it one last time, recycled the fuel tanker for RocketParts to stock the 350 km space station with (eventually all the RocketParts will be getting shipped to the Munar Spacedock- and the 350 km space station scrapped. It just makes more sense to launch one of my heavy fuel tankers, and then send it onward to the Munar Spacedock with its remaining fuel, whenever I need to refuel a vessel in LKO...) Finally, I set the Valkyrie's re-entry/recovery pod on a sub-atmospheric trajectory to recover Bill and Lury like I discussed before, and plotted the transfer to Munar orbit (where it will pick up two more Kerbals from the Munar Spacedock, and then begin a Dunar transfer)- which I will be carrying out and reporting on soon... That's enough for one post though. I hope you guys have been enjoying this so far, despite progress being slow. Soon comes the good stuff though- the arrival of the Duna flotilla at its destination, and of the SSTDABK spaceplanes after they refuel (in the case of the Blackhawk) and each make their transfer burns... Regards, Northstar

Dang! I had forgotten just how *HUGE* my launch platform was for my Heavy LFO Tanker. No wonder I wanted to move my hub of operations to the lower gravity and thinner/nonexistent atmospheres of Duna and the Mun... Well, anyways, I got the Heavy LFO Tanker into orbit to refuel the Raven Mk2- though I forgot the optimal staging times since it's been so long since I launched one of these into orbit (in real-life time)... I also realized something after dumping the bottom stage at extra-atmospheric altitudes (see the final image)- with a slight re-design to move a *little* more of the fuel below the orbital booster (middle) stage, I could essentially turn this rocket into a rocket-SSTO (minus the SRB's). That would more than DOUBLE the dry-mass I would be bringing into orbit with each launch, with a very small marginal cost in fuel. The bottom stage could then be dumped in low, stable Kerbin orbits, and be recycled by my scrapper ship for large amounts of additional RocketParts at a low cost... Kind of reminds me of how it was proposed SEVERAL times that NASA do something similar to bring the Hydrogen-Oxygen fuel tanks for the Space Shuttles into stable Earth orbits, more than doubling the solid-mass orbital payload of each launch, and allowing recycling of the tanks into the backbone of a large space station or something else useful- but rejected the idea several times out of stubbornness... UNLIKE NASA, I *will* be listening to the laws of economics- whenever you can get a large benefit at a small marginal cost, DO IT! Regards, Northstar

Got stuff to do IRL right now, so might be a bit longer before I actually refuel the Blackhawk Mk6 and send it to Duna... (also, as you can see from the pictures, the LFO tanker will also need to fix its inclination a bit before or during the rendezvous) But, soon enough I'll get that done, finish the Valkyrie's mission (as described above), and get the raven refueled so I can send it off to Duna as well... Anyways, I circularized the LFO tanker, and refueled the Valkyrie. Here are the images: I'll be finishing these last few missions, recycling the damaged Raven Mk2 and obsolete 350 km space station, and shipping every last bit of RocketParts and fuel available to either the Mun or Duna soon enough... Then, it'll just be a matter of my long-awaited colonization of the Duna, and less-awaited construction of a sustainable Mun outpost... I hope you guys have enjoyed this thread so far! Have fun with KSP, and I'll catch you all on the flip-side! Regards, Northstar

So, after a bit of wrangling with EVA's, I transferred Chadlas Kerman to the 350 km space station, Lury and (the) Bill Kerman to the Valkyrie's reentry pod, and Aldgee Kerman to the Valkyrie's service module: Of course, after all that messing around with long-distance EVA's to save fuel on attempting actual soft-docking, I realized the Valkyrie didn't actually have enough fuel left without refueling to return its re-entry pod to Kerbin and still circularize its orbit afterwards (it would have enough to raise its periapsis back above the atmosphere, but would run out of fuel in doing so and be stuck in an elliptical orbit). SO, I will be docking the Valkyrie with the space station after all, refueling it, and THEN after returning the two Kerbals in the re-entry pod to Kerbin transferring to the Mun to pick up two more Kerbals, additional fuel, and a new re-entry pod before departing for Duna... I also still need to launch another LFO tanker to refuel the Raven Mk2 (I'll use one of the manned variants I developed earlier so I won't have to develop a new tanker just yet, and so the two pilots can top out the 350 km station's 4-Kerbal crew capacity.) Sorry for all the delays guys/girls... Anyways, the long-distance EVA's at least made for some nice pictures. Regards, Northstar

OK, so just a heads-up: I've decided it best to create a new thread entitled "Kerbin and Beyond: Colonization" that continues this storyline once my first Kerbals make it to Duna... This thread has simply gotten too long by this point, and I think it's the eventual colonization of Duna that most people have been waiting for... Anyways, I circularized my first LFO-tanker, and the second one has entered the Mun's SOI... Tanker #1: Tanker #2: It looks like Tanker #2 will be the first in position to rendezvous with the Blackhawk Mk6... Meanwhile, the Valkyrie is en-route to my 350 km space station with my two brave Kerbonauts from the damaged Raven Mk2: Note also the approaching alarms for my Duna Flotilla's impending arrival at its destination... And, I also remembered I have a Kerbal who's been sitting in the Microwave Power Station's service module for quite a while. Time to get him out of there... (soon) Finally, here's an image of the 350 km space station and the docked Scrapper Ship. I'll be needing to send the Scrapper Ship to salvage the damaged Raven Mk2 soon... I plan to unload the Kerbal onboard the Scrapper Ship and one of the station crew members to the Valkyrie's re-entry pod for a return to Kerbin. Meanwhile, I will swap one of the two Kerbals from the Raven to the 350 km station, and load the other to the service module of the Valkyrie for an eventual transfer to Munar orbit- where the Valkyrie will refuel, re-equip with an enhanced (with extra parachutes and a small rocket motor) reentry pod for use in thinner atmospheres, take on two more crew members, and begin a transfer of three Kerbonauts to Duna... The Scrapper Ship will then have an empty seat to pick up the Kerbal from the Microwave Power Station. Regards, Northstar

I never leave Kerbals behind- and the failed Raven test-flight that nevertheless made it to orbit (and thus was not reverted: the damaged vessel will make for a fine bit of scrap and leftover fuel for my orbital recycling operations- the Scrapper Ship currently being docked with the 350 km space station) is yet another demonstration of that point. I utilized the Valkyrie Crew Recovery Vehicle/ space-taxi system for recovering the damaged vessel's crew- precisely the kind of mission it was designed for: The intention here is to shuttle the two brave Kerbonauts to my 350 km space station- which I've decided to scrap/recycle in the long-run for a version with even lower part-count, at the expense of the KSP-I labs and power-generation system: the latter of which I found would require deployable radiators to work properly- and I have no intention of using due to the collision hazard and extremely low forces necessary to break them (never featured in this thread, but I once had a *KERBONAUT* accidentally collide into one of the Early Spacedock's deployable radiators at extremely low velocity on spacewalk returning from attaching a KAS winch to a nearby vessel. The radiator shattered into a million pieces- but luckily I quicksaved right before the spacewalk...) I also have begun maneuvering the first of my LFO tankers into position around the Mun. Once both are in stable orbits, I will maneuver whichever is in position first to dock with the Blackhawk-Mk6 (which is currently in a parking orbit of 500 km above the Mun- selected as the 'Target' above), and after refueling it will finally set it on its transfer orbit to Duna. The 'Raven Mk2' will also await refueling- but in its case I decided to launch it straight from low-altitude Kerbin orbit: due to its higher vacuum TWR than any of my previous SSTDABK spaceplane designs (when utilizing both the RAPIER and Orbital Achievement Device), as well as how far Duna *already* is from an ideal transfer position... (a tiny bit *PAST* closest approach by the time the Raven makes its transfer) Regards, Northstar EDIT: Also worth pointing out- the Raven experiences quite a bit less vacuum lag than the Blackhawk Mk6- apparently due to it only having two (giant) control surfaces instead of the Blackhawk's eight control surfaces. This makes precise transfers from low-altitude Kerbin orbit much more feasible...

I don't know if you already figured out why this was happening, but I've had that problem more than a few times myself in generating my line of KSP-I/P-Wing SSTDABK (Single Stage To Duna And Back To Kerbin) spaceplanes, so let me share a little insight: (1) The P-Wings have a LOT of lift relative to the overall craft. Extreme wing-wobble with very high lift, unfortunately, seems to be a feature of the stock game- and might be part of why the designers only give us such puny stock wings to work with... Since the lift coefficient increases exponentially (I think by a power of 2) with wing surface area in the real world, you're going to end up with a lot more lift on that craft than you might otherwise expect- if P-Wings follows real life patterns... (2) With that many engines, you have rather high TWR at takeoff. Combine that with high lift coefficient, and you'll have extremely high lift forces at takeoff, also not good for plane stability- especially with large P-Wings... (3) Like was mentioned earlier, you have very little aerilion surface area (if any). Your roll-dampening control surfaces need to increase in size in proportion with your wings, or you don't have a prayer of maintaining stability. High SAS force may somewhat alleviate this problem, as what you have is essentially uncontrolled rolling (with bouncing back and forth as the air pushes the wings back when they move up/down)- but what you really need is some aerilons. Use wing-mounted landing gears with high clearance to protect them from runway/terrain impacts if necessary. (4) You really, really need to keep in mind how screwed-up the stock aerodynamics module is. In stock, drag is proportional to mass- so those heavy nuclear reactors on the wings are generating a TON of drag despite their small profile, and the extra drag on the wings really isn't helping with stability either... (5) Last, but not least, MechJeb seems to have an especially hard time piloting vessels with large P-Wings. I'm not sure if this is due to the size factor, or them being P-wings, but if you're using the ASAS in surface-mode, or some other autopilot functionality (such as the one from Firespitter), it has a very difficult time piloting craft with very large wings near sea-level, and tends to over or mis-correct for roll. This tends to generate 90% of the flapping-motion observed in my experience: especially with very low angles-of-attack. Even the stock SAS has some problems with the really large-winged craft. Your best bet is probably to launch the thing all-manual, and only switch over to autopilot after reaching at least 3000-5000 meters. (6) If all else fails, don't forget you can always launch your plane at reduced thrust. Often, I find that in these situations it helps to start the thrust at full to accelerate on the runway, then dial it back just before takeoff. Don't forget that the wing-mounted thrust itself can also destabilize the craft- especially with KSP-I thermal turbojets: which have no thrust-vectoring capabilities to help counteract this and steer the craft. I hope all this helps. Also, don't forget that P-Wings seem to have several annoying tendencies based on the game only processing wing attachments as "point-attachments" occurring at just one location: usually halfway between the ends of where the wings contact the fuselage (this applies to stock as well as P-Wings). This same rule also seems to be responsible for the annoying tendency of P-Wings to show CoL as too far forward with procedurally-designed swept-wings attached: as P-Wings are apparently not compatible with generating lift displaced from the attachment point more than a certain (small) amount... CoL will always show up right near the attachment point with P-Wings: no matter how far they are swept back... Regards, Northstar P.S. You can see quite a bit of detail on my SSTADBK designs on my Mission Reports long-thread... I've used P-Wings for almost all my later aircraft designs, so I had to work through a lot of associated problems that introduced. Even when I don't explicitly discuss problems I encountered, sometimes I hint at them, or you can catch glimpses of how I dealt with them from the screenshots of my flying and the designs themselves... http://forum.kerbalspaceprogram.com/threads/57509-Kerbin-and-Beyond-a-Maturing-Space-Program

Ok, so I've been quite busy designing the RAPIER-Thermal Turbojet hybrid spaceplane model I promised before, and here it is. I call her the 'Raven Mk2'. She's not only a SSTDABK-capable spaceplane, she's also my highest-altitude jet on Kerbin ever (when the RAPIER engine is in AirBreathing Mode, she can hold over 34,000 meters). Here are images for the Challenge Run... MAJOR Design Refinements: (1) Relies on Thorium-based nuclear reactors instead of Uranium-based nuclear reactors (still pre-Fusion tech only requiring the stock Nuclear Propulsion node. Produces 37.5% more ThermalPower, close to twice the thrust, and Thorium is slightly lighter than Uranium. On the downside, it requires a LOT more regular maintenance.) (2) Utilizes just TWO of the new Procedural Dynamics control surfaces to greatly increase stability & control while simultaneously slashing part-count and lag. (the control surfaces, found at the rear of the lower wings, were increased to near-maximum size for the design) (3) Incorporates a RAPIER engine to greatly increase weight-efficiency of the ascent system. When leaving Kerbin's atmosphere, the Raven Mk2 moves from Twin Thermal Turbojet (T3J) power (all intakes open on Liftoff), to combined T3J/RAPIER-AirBreathing power, to T3J/RAPIER Airbreathing/Conventional-Rocket power, to T3J/RAPIER ClosedCycle/Rocket power (radial intakes closed at this point), to RAPIER CC/Rocket-only power (inline intakes closed at this point), to orbit circularization just with the higher-ISP conventional rocket (a NovaPunch2 1.25m Orbital Achievement Device- 405 ISP but low thrust). The complex patterning of engine activation and deactivation, as well as timed intake-closure (radial intakes before inline intakes, as radial intakes choke the RAPIER in ClosedCycle Mode, and cannot be precooled) is designed to maximize efficiency. The result- the Raven Mk2 can ascend to orbit on less than a quarter the fuel of the Blackhawk Mk6. (which also saves on fuel-tank weight) I know it seems I've launched an awful lot of spaceplanes at this point, but previously I took to showing my failed designs as well as my successes... (at this point, I've skipped over the failed models I was working on, such as the Raven Mk1) I'm also rather reluctant to enter the Eagle Mk2 or the Blackhawk Mk6 into this challenge after learning the intakes I used produced no drag. It just feels kind of cheap to rely on those entries to meet the challenge requirements... I'll still test those models out on Duna (it'll teach me a little more about Duna aviation in preparation for the Raven Mk2), and even post them here so anybody who wants to can use them for inspiration, but unless I am unable to successfully fly the Raven Mk2 on Duna, I'm going to try and use this model rather than my previous thermal turbojets to meet the challenge's requirements... Regards, Northstar P.S. I know there are no images of the plane on the runway here- I forgot to snap images of the final version before Liftoff. If you're curious though, you can find runway images of a slightly earlier version of the Raven Mk2 (with *slightly* smaller Procedural Dynamics wings) on my "Kerbin and Beyond: A Maturing Space Program" thread. Hopefully this doesn't disqualify my entry... http://forum.kerbalspaceprogram.com/threads/57509-Kerbin-and-Beyond-a-Maturing-Space-Program

I present the final (successful) version of the Raven Mk2. This launch will also be used for another challenge run in the Flying Duna Challenge... Not only is the Raven Mk2 a SSTDABK spaceplane- it is also my highest-altitude plane when relying on jet and thermal turbojet power only as well... (with an altitude ceiling of around 34,000 meters). I look forward to seeing how she performs on Duna (where the RAPIER engine will obviously be worthless in AirBreathing Mode, but the reduced gravity and planetary radius should greatly improve Twin Thermal Turbojet performance...) Regards, Northstar

Test flights with the Raven Mk2 haven't been going as smoothly as I hoped... It turns out that there are quite a few ways to accidentally blow up the spaceplane's engines, including turning the RAPIER engines back to AirBreathing Mode BEFORE re-opening the RAM Intakes... This resulted in a rather unfortunate accident- but at least it did yield some nice pics... (right-clicking shortly after the accident revealed that a very small fraction of air still forces its way in even when the intakes are closed- but the precoolers remain inactive, and this fraction is superheated enough to explode the engines...) Unfortunately, this now means two of my Kerbals are stranded in space in a damaged ship of uncertain stability during re-entry flight (still symmetrical, but the Center of Lift might be too far off now) So, I'll be sending a rescue flight soon- possibly from the surfacr, or maybe from the Valkyrie Crew Recover Vehicle- which is already in orbit over Kerbin... Regards, Northstar

I present the Raven Mk2, and a rather unfortunate test-flight that both proved its orbital capabilities, and failed miserably at the same time... Here are the 13 images of the unlucky flight: I learned 3 things from this flight: (1) RAPIER engines are suffocated by having too many open air intakes when in ClosedCycle mode. In order to obtain anywhere near maximum thrust, I need to close the radial intakes on this design to get the RAPIER's full thrust (175 kN with closed intakes vs about 40 kN without). I am unclear if this results from stock or KSP-I engine rules... (2) The thrust three stock RAM intakes and several radial intakes allow for a pair of Thorium-powered Thermal Turbojets at 32,000 meters is absolutely pathetic. This presents potential problems for the turbojet altitude ceiling of this craft on Duna... (although it will definitely be able to escape Duna's atmosphere as a spaceplane, refueling in low Dunar orbit will probably be necessary) (3) Re-opening the radial intakes on this design at high altitude is a VERY, VERY BAD IDEA (it leads to the Twin Thermal Turbojets EXPLODING due to overheating, as the radial intakes have no precoolers) Nevertheless, although this attempt resulted in running out of Oxidizer before escaping Kerbin's atmosphere due to wasting a large part of the vessel's Oxidizer in running the RAPIER engine in ClosedCycle mode with the radial intakes open (this actually produced LESS thrust than running it in AirBreathing mode at the same altitude- about 40 kN vs. 48 kN), it became extremely obvious that with careful management of fuel utilization, the raven Mk2 can *just barely* achieve stable Kerbin Orbit (launching a refueling tanker will prove necessary). I look forward to presenting the first successful orbital attempt with this craft soon. In the meantime, adieu, and fly courageously. Regards, Northstar

Sounds fair enough- though the design I was specifically referring to was the KSP-Interstellar design. The electric propeller Firespitter/NearFuture) design he submitted works fine in later versions of KSP and KSP-I AFAIK... Regards, Northstar

WHOA! Guess I was right about the high altitude ceiling on the Raven's airframe minus the T3J's, by the way. Here she is at maximum cruising altitude: OVER 33,000m! (on mostly full fuel tanks- but with no Oxidizer- I dumped it all after losing the T3J's- as I decided I was NOT going to try and take this thing to orbit without them... Guess I should have reconsidered- still a useful spaceplane in its own right even without TTJ's for long-term use on Duna...) This design performs on a level with my very best high-altitude jet-powered craft desings: so at least I know the basic airframe works exceptionally well before I slap back on the thermal turbojets... (which should provide additional thrust at no extra cost beyond the engines themselves if they work correctly- as IntakeAtm is an entirely separate and parallel resource to IntakeAir, provided by the same existing intakes) New (more stable) designs will be coming out soon. I'll probably stick with over-wing Twin Thermal Turbojets, though, as it would allow me to slap on additional inline intakes and precoolers without exceeding a 3:1 intake ratio (usually the intake limit I set on myself to avoid cheaply exploiting the intake mechanics- though occasionally I go 4:1 if only 1 is an inline or it's all-radial...) I noticed with the RAPIER engine that thrust was not even limited by available air supply- it was limited by the threat of overheating due to the KSP-I modeled compressive heating of the air from the radial intakes... (which do not benefit from precoolers) Regards, Northstar

I don't mean to spam you guys with posts about my spaceplane development, but it's been a continuing side-project of mine while I focus on getting my flotilla to Duna (which, I realized, won't be nearly as hard as I thought- a recent check on the vessels to add Kerbal Alarm Clock nodes for their Duna SOI transitions reminded me that the electricity from running the NERVA engines on the models relying on NearFuture reactors should provide more than enough electricity to keep them running until a stable Duna orbit is achieved...) And, sometimes, you learn more from your failures than your successes. Take, for instance, my latest test-flight of the Raven: She flew fine until reaching a bit over 10,000 meters- at which point she began losing stability as the SAS was saturated, and eventually went nose-up and into a series of rolls and dives that culminated in the loss of both thermal turbojet engines... (as can be seen in the last two images of the album) However, that caused me to notice two things: (1) The airframe flew nearly perfectly as a glider with just the RAPIER engine attached. This confirmed my strong suspicions that the problem was that she was a tail-dragger due to the combination of asymmetric drag (remember, in stock KSP, drag is proportional to mass- so your engines generate a TON of drag... pun intended...) and a Center of Lift that was too far forward to compensate due to the bugginess of Procedural Dynamics not adjusting the Center of Lift *AT ALL* for swept (like in my design) vs. straight wings... (I initially thought it was inverting the Center of Lift- but it turns out it just doesn't move it back if the wings are swept back...) (2) The damaged Raven showed it could still maintain a fine climb rate (and likely a high altitude ceiling) with just the 50kN of thrust from a single throttled-back RAPIER engine. Additionally, before the thing went nose-up, it had become obvious the limiting factor on the altitude ceiling was going to be the intake area, rather than the lift-mass/drag ratios of the craft (which were quite impressive- Procedural Dynamics seems to model aerodynamic forces increasing as the square of continuous wing area, like in real-life, by altering the lift coefficient depending on wing size... GREATLY rewarding the Raven's huge wings...) By the way, here's one more shot of the Raven at 18,000 meters with a still VERY nice rate of climb (I expect to make at least 27,000 meters at full throttle), and throttled to less thrust than the twin thermal turbojets (T3J's anyone? I think I'm going to have to make that term a "thing"...) could provide at a lower altitude... (their thrust would have been even higher at this altitude) What all this says to me is that I need to make some design refinements... Here are my ideas: (1) Consider moving the thermal turbojets to an over-wing position (an under-wing design will only make the tail-dragging worse, and have issues with colliding into bumpy terrain on rough landings) or one on the top of the fuselage further forward, since Procedural Dynamics has insisted on placing the Center of Lift much further forward than it should be... (2) Consider whether I really need 2 thermal turbojets, or if just one would be superior. Two TTJ's may provide better thrust at lower altitude, perhaps even in the ranges relevant to low-altitude flying on Duna- but they will also just add extra weight if the plane can reach the altitude ranges where the same thrust could be achieved by routing all the intake air to just one thermal turbojet (for this reason, as well as avoiding asymmetric flame-outs, most of my high-altitude plane designs featured just one engine. I had no need for this design strategy with the OP'd KSP-I atmospheric intakes with 4x the area of a Ram intake and no drag- but now that they are gone, I may be wise to go back to this weight and lag-saving design principle.) The extra weight will also make landing more dangerous and difficult by increasing the wingload... I'll soon be turning out a Raven Mk2 after I decide whether I'm better off with two top-mounted TTJ's (and perhaps a couple more intakes- I'm currently at 1 inline and 3 radials for two engines- so maybe a 3:1 ratio with 2 more inline intakes...) or one tail-mounted TTJ. I'll have a (better) working model for your guys' enjoyment soon either way! One last thing: let me know if you guys want the craft files for any of my designs (you can post here, or PM me), rocket OR spaceplane. I'd be more than happy to share them. Just keep in mind I'm running quite a few mods, and most of my designs include parts from KSP-Interstellar, Novapunch2 (struts on spaceplanes, engines as well on rockets), and B9 Aerospace at the very least... Regards, Northstar

Took at the view-count recently, and I am EXTREMELY IMPRESSED by the number of people at least viewing this thread. Hopefully they're also reading all the way through. As a result, expect another special roleplay-heavy post on at least one of my Duna landings- which aren't all that far off at this point... (I just need to finish consolidating my position near the Mun, and get the beginnings of a more permanent base down so I don't feel like I'm abandoning my Kerbals who touched down on the now-obsolete Munar Science Lab...)

Is anything going to be done about the CoL offset bug? This is the not the first time I've posted on this, and nobody even seems to notice my posts on it... The problem appears to arise from the CoL *ALWAYS* being centered halfway between the ends of the wing attachment points- regardless of the sweep angle of the wings. The CoM, on the other hand, DOES respond to wing sweep. What this always and inevitably results in is craft with rear-swept wings always being WORSE tail-draggers than those with straight (unswept) wings- which is precisely the opposite of how it should be, and a real hassle in craft design as the weight of heavy engines at the rear (under-wing designs have too many problems with smashing their engines into the terrain on rough landings) requires me to pull my CoL back to prevent the craft from going nose-up...

Well, I have my concerns about Steven's entry... You see, since he posted that, thermal turbojet aircraft have been GREATLY nerfed... In particular, the atmospheric intakes he used have been removed. It turns out they had 4x the intake-area of a RAM intake, and due to a coding technicality, were producing *NO DRAG*- which is why they were removed. Obviously, removing a dragless, 4 times more effective intake option which he used in his craft means future competitors are at a serious disadvantage... Additionally, KSP-I further nerfed Thermal Turbojets by introducing a precooler part, and requiring it to fly at high speeds. So, anything like Steven's design would now EXPLODE without precoolers- which add additional mass, weight, and drag... (and increase part-count: necessitating even smaller overall designs to counteract this...) What I propose is, KSP-Interstellar designs before 0.9.1.1 (when the precoolers were added, and the option to Atmospheric Intakes removed) be placed in a separate category. It is simply IMPOSSIBLE to replicate the kind of performance that was possible with 2.5 meter Atmospheric Intakes with stock Ram Intakes or B9's SABRE Intakes... Those players who launched designs before 0.9.1.1 are at a serious advantage (including myself)- since the Atmospheric Intakes have been removed in such a way that new craft can simply no created using the intakes, but existing craft that already contain them will still have them and function for at least a couple more versions (meaning I will still be able to fly my Eagle Mk2 and Blackhawk Mk6 designs on Duna, which both used KSP-I Atmospheric Intakes- but nobody else could replicate these designs if they wanted to...) Regards, Northstar EDIT: I just wanted to correct myself. I hadn't actually played with precooler functionality in KSP-I yet (even though I was using 0.9.1, where precoolers were required, I was also unable to reach sufficiently high speed/altitude to even need them due to a bug with uneven thrust), so I wasn't quite sure exactly how they had been implemented. It turns out it's not actually a separate part- but new functionality for stock and B9 precoolers- so they actually do something useful in cooling the intake air. As stated before though, this is a nerf- without these parts, thermal turbojets *OR* RAPIER jets will both explode at sufficiently high speeds... (KSP-I modifies the stock RAPIER engines to also require precoolers) EDIT #2: Ack, I know it's the post-Christmas slump; but I really need to watch my words a little more carefully. What I MEANT to say, is KSP-Interstellar modifies the "Radial Engine Body" from stock already in the game (which doesn't actually do anything except add weight, part-count, and drag to your planes) into an "Intake Precooler" which actually does serve a purpose- in preventing the air compression-based overheats of TTJ's and RAPIER engines that KSP-I now makes possible. As stated, it also makes B9 Aerospace' precoolers functional for this purpose as well.

I have discovered the wonders of combining Thorium reactors with Thermal Turbojets and RAPIER engines! And, designed THIS as a result. I call her the 'Raven': Those images were from a relatively successful test-flight, until, unfortunately, I ran into a bug present in the thermal turbojet logic for KSP-Interstellar 0.90: As you'll notice, the engines are producing VERY uneven thrust. This began with still around 50% IntakeAtm remaining, and the IntakeAtm is only low in the screenshots due to the spin the plane consequentially entered... I've updated KSP-I to 0.9.1.1, and this MIGHT fix the bug: but I wouldn't bet your life on it... Regardless, using Thorium rather than Uranium reactors increased the thrust of my thermal turbojets by roughly 50%, at the cost of requiring greatly increased maintenance (Actinide wastes build up much faster than with Uranium)- but I should be able to design MUCH more effective spaceplanes utilizing these reactors, and push the limits with them on Duna like never before... Regards, Northstar EDIT: Bug was not fixed in KSP-I 0.9.1, but is fixed in 0.9.2, which I now have installed. I look forward to posting on the "Flight of the Raven" soon!

I thought THIS bug was fixed by 0.90 (version I'm running) Note that the IntakeAtm was a LOT higher (around 50%) when this started happening- it just plummeted by the time I took screenshots due to the spin causing the intakes to point away from prograde... Regards, Northstar

OK, first of all, with emissivity- what are the chances of seeing a radiator with an emissivity GREATER THAN 1 then. In real life, several types of nano/metamaterials actually exceed the blackbody limit by having emissivity significantly greater than 1... So it would seem logical (and more accurate) to make a third-tier radiator with higher emissivity available at Experimental Electrics or Metamaterials, and push back the Graphene radiators to an earlier tech node... Second, any idea when we can expect larger thermal turbojets by? And any chance we could get larger intakes (if it really must be stock, then fine- but surely you could add a 2.5, 3.75, or even 5-meter Ram Intake to go with the larger turbojets? It would help to have intakes available at a 50% or more LARGER diameter than the turbojets, to reduce the number of intakes needed for high-altitude...) Third, what about getting smaller Aluminum Hybrid Rocket Engines like I asked about before? I can't see any reason the engine needs to be as large (and heavy) as a small house at Kerbal-scale... Regards, Northstar