FleshJeb

This is literally my first time messing around with BDA, so I made: https://www.dropbox.com/s/6x57xspr94no3sf/Be Gentle.craft?dl=0 It ain't fancy, it ain't optimized, and it doesn't know if it's an F-16 or a Dassault Rafale. I tweaked a few pilot settings and had Jeb and Val go at it. It works. Is there a set altitude for this competition? I know most of these have one. I got some coaching, so please run this with BDA settings of Interval 5, Burst 5, Missles/Tgt 4, and AI settings of Default Alt 1500, Min Alt 500. EDIT: Forgot to mention that it's Stock.

I think you can just edit your save file and toss this in the command pod. I stole it from the MechJeb And Engineer For All mod. I find the Rover Autopilot burns a LOT more electricity than is necessary by matching the speed too aggressively. Half the time, wheels are oscillating between forward and reverse. It also can't seem to climb hills to save its life--It won't full throttle up a hill any more, even with wheel friction set to 5.0 and traction control off. I just upgraded from KSP 0.25 to 1.31, and it used to be great.

I'm sorry Azi. That's a stunning tribute, and it says everything.

Thanks for the info! Is it true that if you put a Shock Cone on the back end of a Rapier and offset it inside that it reduces the rear drag on the engines? Those are about 5% of my total drag, thus far. BTW, before I get too far, thank you for posting this. I'm having a lot of fun, and have learned an enormous amount just from dissecting the Starion. Also, yours is the first other person's craft I've operated since starting 4 years ago. Editor Extensions is working for me in 1.31.1891 (Win64). I think the default KSP behavior is to rotate 5 deg with Shift-WSAD. I'm using RCS BuildAid as well. I tried CorrectCoL, but I deleted it for some reason. I noticed your trim flaps. I just haven't found a need to configure any on mine yet. Hmm, that makes a lot of sense from a drag perspective. I'm going to have to play with that a bit. My only concern is that wings have a slightly worse mass fraction than tanks. (83% instead of 89%) This may not end up being significant. Hmm, I JUST rediscovered the MechJeb window that shows total drag and gravity losses.. Regarding parts choice: The Precooler must have some insane emissive constant. That's what I'd put in front of your Nervs. Pretty low drag too. I have to stop myself from using them so much as the mass fraction is only 53%. You could probably get away with the Type A nosecone (2000K thermal limit). I think they're the second least draggy nose after the long tail pieces. I'm using two small reaction wheels in one of my service bays, and they're working fine. Right now, my optimization path/future plan is: I've been aiming more for mass-fraction in orbit--Under the assumption that more than one Nerv is a waste. 3 Nervs = 2 Rapiers + 1 Nerv + 2 tons of fuel. To put on just enough wing that the plane stops lifting just before Rapier jet burnout. (There may not exist a practical maximum amount of wing.) Just enough LFO to be able to reach an equilibrium speed where the minimum number of Nervs don't start falling: This point may not exist. I'll probably have to throttle back the closed cycle mode on the Rapiers and do a long joint Nerv/Rapier burn. Have a fully-fueled craft after staging the drop tanks away. This is where my 2 tons of advantage comes in. I suspect the optimum mass fraction in orbit is going to come from a 2 Rapier, 1-and-a-fraction Nerv design. I'm going to try a 2-and-2 FYI: I took the fuel out of our drop stages and compared the cost: You go from 107,621 - 101,771 = 5,850 I go from 70,885 - 66,830 = 4,055. Tanks are still pretty cheap. Of note: I just SSTOed a 3 Rapier 2 Nerv, and had 1500m/s remaining after circularizing. It's not really optimized; I just threw it together by gut feel. It could use much more wing, and I could strip off quite a bit of excess weight.

I just got this to orbit with over 2150m/s left in the tank. It could still use a lot of tuning. The Wet-Mode TWR is about 1.2, when the Nerv starts running solo, it's 0.25-ish. 1.5deg up on the runway. 10 deg up, slowly leveling off to 0 at 22km. Run to about 1635 @ 23.4km. Hit Srf+0, engage Closed Cycle and Nerv. Around 40km, the Rapiers burn out, and the drop tanks stage. Keep Srf+0 until pitch = 0 (around 47km?), then go to Srf+ 2. It'll do a bit of a descent (to <40km), return to Srf+ when it wants to climb again. Shutdown Nerv when Apo = 95km min. I shut down at Apo = 98km, and the wings lofted it to 105km. I'm pretty sure you could SSTO with 3 Rapiers + 2 Nervs. Maybe a Whiplash/Panther and 2 Rapiers. I tried to make a 1 Rapier + 2 Nerv plane work, and it would not. As a general rule, I think optimum TWR is dependent on L/D, but more importantly, Thrust/Drag. T/D is dependent on altitude. The zone between the top of the speed run and about 37km is worth getting out of quickly. I believe jet-mode Rapiers will always be superior choices due to the fact that they're they ONLY engine than can traverse a certain region at such a high ISP and reasonable TWR. Basically, you're running on ion engines for a 3-5km band. I'd take them even if they didn't have closed cycle. What's the optimum L/D pitch for a wing? In the old Aero, it was around 26deg (which is ridiculous) https://www.dropbox.com/s/w2i9uk93c99nqv0/AeroGav 2STO v2.craft?dl=0

I WAS getting a bit ahead of myself. I only upgraded from v0.25 a couple of weeks ago, and I've been experimenting like mad. I've gotten pretty good at designing for drag and thermal. I flew your craft on 1x Kerbin--It's beautifully balanced and tuned. Very, very elegant. So, I just downloaded 3.2x (Galileo88 - is there another version?): HOLY CRAP, YOU WERE *NOT* JOKING. I did not get to space today. I can get my Apo out of atmosphere, but I don't have enough left to circularize. The loss of comparable centripetal force is killing me. Just based on that, I'll need about 175% of the lift that I've currently got at the switch from jet speedrun to closed cycle. I calc'd [g(altitude) - a(v_tangent)] for both scalings. Based on my necessary pitch angle (5deg up craft pitch = AOA 5deg) (35km @ 2450m/s), I'll need about 200% of my current lift to maintain a zero craft pitch [sin(10)/sin(5)] ~ 200% I want to verify that the atmo scaling is 16% higher. Is this correct? In 1x, I like to do my speedrun at 21km => 24.4km, and get above 32km => 37.1km before going on pure nukes, to clear the worst of the atmosphere. Speedrun: 1x Kerbin = 21.5km @ 1667m/s, 3.2x Kerbin = 21km @ 1667m/s. So, I know you want to answer what an optimal range for TWR is--I think the another pertinent number is L/D. 11.32 "lift units" @ 5deg for 26.375tons = 0.42 lift / ton. I'm going to try for 0.84 lift/ton and see how that works. You're at about 27.75 lift/36.638tons = 0.75 lift/ton This is assuming we're both close to minimum drag for a "3-column" design with an Inline Cockpit, and two Crew Cabins. More wing will be a little worse, but we'll see what happens. For the TWR question, you want the Nervs to be a least better than a good LFO Isp. In your top pic, you've got 180kN thrust - 65kN drag = 115kn. This goes to an effective Isp of 800*115/180 = 511 My effective Isp with one Nerv was between 266 and 133. These are not counting the work the wings are doing, but I don't know how to math the radial out contribution. I guess you could integrate how fast the drag falls off to figure how it affects the average effective Isp for the whole run. How much range do you want in space? That affect the choice of discarding the Nerv entirely or not? If we're just meeting a space station, it could be minimal. FURTHER THOUGHTS: Did another jet speedrun with my design: 1669m/s @ 21km => 100.5kN drag. This tells me a few things about that moment in the flight : If your design experiences similar drag at similar speeds, you'd have an effective Isp of 356. [800 * (180kN -100kn)/180kN] When I light my two Rapiers and the Nerv, my effective Isp is 254, but that changes QUICKLY. In zero drag = 336 If I had two Nervs, and one Rapiers quit, I'd only have an effective Isp 0f 270. In zero drag = 405 In short, yes, it's possible to establish an optimum TWR/engine choice if we can graph drag, speed, and altitude for some reasonably optimal zoom climbs for the higher TWRs. I think I'll write a KRPC program to log data. That'll be later this week.

You want to have a truly ridiculous notion--Try a 3-STO. If you're going to toss away Whiplashes, tossing cheap rocket parts isn't that much worse. I tested about 10 different major configurations on normal size Kerbin, and extrapolated remaining dV for 3.2x. https://www.dropbox.com/s/c6zs66lgjs56zvj/AeroGav 3STO.craft?dl= Flight profile: Get to crusing altitude Hold 0 pitch for the jet speed run Fire NERVA and slowly pitch to +5 At jet burnout, ditch jets and fire Terriers. Pitch to +8 until the lift begins to run out (AOA gets past 5 n the Aero GUI) Discard side tanks and Terriers when all fuel runs out. (I had a little Liquid Fuel left when the Oxidizer ran out.) Pitch to prograde. (I had over 4k dV remaining after circularizing on normal Kerbin) AG1 - Whiplashes AG2 - NERVA AG3 - Terriers AG 5 - Service bays AG 6 - Solar Panels FYI, I found out that the 1.25m reaction wheels are remarkably draggy. I tucked mine in service bays. EDIT: This one is better: https://www.dropbox.com/s/f29u0sl2k4r3130/AeroGav 2STO.craft?dl=0

https://wiki.kerbalspaceprogram.com/wiki/Mun#Terrain You may find this useful.

Wow! I need to do some reading. I had no idea. I'd be willing to bet that this will be a very valuable technology precursor to Bussard Ramjets.

I have similar, but less ambitious plans. I finally got into 1.x last week, and I've been playing with various Ekranoplan designs, and getting really good and convincing low-level performance. Perhaps you can answer this: Is there an occlusion bug with Mk3 Cargo Bays? I'm toting two orange tanks as test mass, and the docking ports show no drag, but the tanks, which span cargo bays, do. Ordinarily, I wouldn't care too much, but L/D ratio is kind of the whole point with an Ekranoplan.

I did some testing today with a single-engine Whiplash jet: The radiator wasn't helping much with sustained flight, but if I popped up high or slowed down for a bit, it made a difference. Of note, the one large radiator accounted for about 1/3 of the drag of the entire craft. Also, I think the Precooler may have a much higher overall emissivity than the Mk1 LF tanks. It was frequently exceeding or matching them and the radiator in a number of design options.

I've been keeping up, it's the bug notes and changes in editor functionality that that kept me from upgrading I have to apologize, I was having a general rant about software that has 27 ways of doing the same exact thing (I'm looking at you, Microsoft and Autodesk). I certainly appreciate your skill, industriousness, and willingness to work on this sort of project. I've only today become aware of your stable of mods, so thank you, thank you, thank you!

https://en.wikipedia.org/wiki/Drake_equation

I... I... I may have to stop using Tinder...

@MatterBeam may be able to help with math and logic checking on this. He did a great piece on air scoops.

I remember reading something that said not to bother. I know there's a couple of heat pump mods, but I've never tried them. I'd love to see one that "circulates fuel" to try to change or average the temperature of fuel tanks. Hmmm, one could use an interface, similar to the fuel flow priority, to designate which tanks are to be kept warmest or coldest. That way you could try to minimize the temperature of the tank behind the cockpit. These were interesting: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19750009264.pdf http://www.dtic.mil/dtic/tr/fulltext/u2/912902.pdf (pg 63)

I applaud the discussion, but I'm of the opinion that decouplers shouldn't have crossfeed at all--Under the theory that basic parts should be as mono-task as possible. I just upgraded to the current version from 0.25, and it took me 20 minutes to figure out why my fuel lines weren't being obeyed. The simplest solution to all this is to make fuel lines massless and dragless.

@Ten Key That's a fantastic video. I used to do cicumnavigations like that in the old aero. My record is a little under 23 minutes. IIRC my velocity was somewhere between 3300 and 3600 m/s, altitude 55km, with a continuous downward thrust of 1.2g. The rocket had 21 to 23 km/s of dV.

The Klonkorde is a 72-passenger, Medium Regional Jet by FleshJeb Studios. Album /a/Yu6HK will appear when post is submitted https://kerbalx.com/FleshJeb/Klonkorde Cost: $69,958,000 Cruising speed: 6500m @ 276 m/s. Please see pictures for testing data. The Klonkorde is powered by one highly efficient Goliath engine. The large, rear-mounted turbofan makes for a VERY quiet flight. Our roomy Mk2 passenger cabins and quiet operation make for a luxurious ride. In addition, the front two cabin sections are separated from the others, and can be outfitted as a first-class section. The inclusion of a probe core means a library of the finest in in-flight entertainment, plus the ability to support android flight attendants (save on those wages!) For the sophisticated Kerbal, the android flight attendants can BE the in-flight entertainment--We assure you that they are FULLY functional. The extremely narrow planform saves you valuable floor space in the hangar. Unlike our competitors, up to four Klonkordes can be staged and ready to exit the hangar doors at the same time--Perfect for the peak holiday season. The takeoff speed of 84m/s is slightly faster than requested, but with such a powerful engine, the required runway distance is short. Other Stats: Range: over 2000km. It exceeds 1500km even at a lower and faster cruising altitude of 4000m @ 321 m/s. Mass: 37.167 tons full, 29.367 tons dry. Dimensions: 39.8m L x 12.2m W x 5.8m T Parts: 50. Fuel: 1560 kal. Fuel Consumption: ~0.204 kal/s. Takeoff speed: 84 m/s. Landing speed: ~75 m/s Action groups: 1 = Flaps, 2 = Thrust-reverser. (The flaps are a bit of a pain; I only use them to slow down.)

Wait, wait..."Control from here" now works as an AG?!? I thought that was broken! This is going to make my hoppers so much easier to deal with.

I run twenty or more simultaneously, using KAC.

Volumetrically, there's an advantage to scaling up. Structurally, there's a disadvantage. Per Galileo:

@Rune I DID neglect to mention the structural advantage of scaling down, but like you said, you can only scale down so far. Likewise, the outer skin of the rocket has to withstand a minimum dynamic pressure (aero) as well. @MatterBeam I don't always agree with your conclusions, but you always force me to THINK. Thank you.

I haven't done any post-v1.0 roving, but here are my tips: Long-distance roving is the most brutal and demanding operating environment in the game. Your design should reflect this. Mun Route: Definitely not polar. The terrain at the poles is brutal. Wide and low are good, LONG is better. You don't want to go tumbling every time you hit the brakes. Strong structural chassis to attach wheels to. Roll cage out of structural parts. Soft parts go in the cage. Nothing that's not a wheel, chassis, or rollcage should be able to touch the ground in any orientation. I make front and rear bumpers out of structural parts. Tumbling at high speed tears off wheels; I make the bumpers eat it first.. Redundant parts. You WILL rip off cage parts and wheels. Your rover is an onion; the ground is a cheese grater. My standard rover has 12 wheels, and I lost half of them doing 500km on Duna. My newer "Baja model" has only 8, but less than half the ground pressure. Prioritize your part placement from most to least vulnerable. Assume your roll cage disintegrates during your trip. What hits the ground next? Will it survive? How critical is it? Anything less than 6 wheels is foolish. Even moderate impacts tend to spaghettify Kerbals in open seats. I don't use open seats. Use the fat-tired offroad wheels. Everything else is garbage. (Pre 1.0 wheels) I like about 4kN of reaction wheels per ton of rover. That will fix most rollovers if you've designed your rollcage right. I like to have no more than two tons of rover per wheel. One wheel per ton is even better. (Pre 1.0 wheels) If you want to make any time at all, you ARE going to fly off some jumps. Put some downward-facing Vernor RCS blocks on it to slow your falls. Land parallel to the surface to minimize the impact on any one wheel. Try not to impact at over 10 m/s downward velocity. (Pre 1.0 wheels.) 1/3 of your rover's mass should be fuel for RCS. The best time to repair tires is when you're safely stopped. The second best time is in mid-air, while hanging off a ladder. Learn to be very fast. Landing on blown tires can result in LONG tumbling crashes. (My record is 3 or 4 km) Do extensive testing. If it can't reliably survive a full-throttle jump off the launchpad, it won't make 10km anywhere else. There's also some good steep terrain a few km SW of the KSC. I usually do at least 100km of challenging terrain on Kerbin before I send mine to other worlds. You will discover maximum survivable speeds for various difficulties of terrain. I try to define this as a speed you can go and only crash every 5km. Any more frequent and you will get very frustrated. Your max speed on the Mun will be about 1/2 the above. Quicksave often. I like to only quickload if the crash is mission-ending. Personal preference: I make MechJeb Rover Autopilot do all my driving for me, and it's still hard. Turn on Stability Control. Route/Waypoint choice is critical. Max speed for that segment is critical. If you're going to let it drive unattended, set the speed to half or less of what you otherwise would for that segmant. If you're actively paying attention, have one finger over R (RCS toggle) and the other over K (RCS up). Mouse hovering over the EVA toggle so you can repair wheels fast. HAVE FUN. My style of fun may be different from yours. Design and drive accordingly.