camacju

Recently I've been having a lot of fun trying to get an orange tank into orbit with the lightest SSTO possible. With a runway takeoff (not using flats or hills), the best I could do is just under 55 tons launch mass, or a payload fraction of 66%. In other words, a 18.86 ton plane can bring a 36.05 ton payload to orbit. Here it is in the VAB And in orbit with the slimmest of margins!

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Another factor is centripetal force. At 60 degrees latitude your bonus velocity from Kerbin's rotation is halved so your centripetal force is reduced. This means you need more lift to stay in level flight, which means more drag, which means lower speed.

That seems to be the best option for high altitude turboprops - I did that for my own submissions. You've probably run out of intake air. I've had that happen before - the solution is to add more air intakes. For example look at my "Vega" submission - the wings are covered in radial intakes..

Actually, it's more because the ascent is pretty low hanging fruit to squeeze more capability into any given craft. When you're doing a mission that requires tight margins, the single most important factor is payload fraction in Kerbin orbit, so a lot of effort is going to go into maximizing that. This means stuff like dragless fairing shells, taking off from the flats around KSC or even from the polar ice caps, precise ascent profiles, etc. Your point about ISRU is why many players don't use ISRU - it gives an extra challenge. Similarly, I never use ions, because some missions are just too easy with them. However there's still plenty of challenge that the stock game offers, especially when you have very tight margins that require extreme care. I don't think the stock game only holds aerodynamics challenges, as long as someone can think of other restrictions that make the game more fun/challenging. Some examples that I've done include missions that must: -be completely reusable (a pretty common one) -only use solid fuel/liquid fuel -only use two/one engine(s) -only use one fuel tank / two categories of parts -cost under 20K/10K funds (it's surprising how much you can do in only 20k funds) -not have connection to KSC -fit in a cargo bay and probably more that I'm not remembering. Point is that apart from fine adjusting aero properties of a plane until you get the desired performance, there's still a lot of fun to be had in KSP.

If you want to be pedantic it's also possible to get a 2/3 payload fraction with no wing parts (other than control surfaces, and these can be replaced with reaction wheels for control authority), and this has been done. As for the 50% mark, I feel like a Rapier + Nerv pure "rocket" can come close to that without any hacky aero optimization. Stratzenblitz has done it without any DLC parts. So that difference doesn't really matter here. Sorry, I misspoke - the specific infiniglide glitch that I used was patched, but others haven't been. The standard Jool "landing" is to dip below 0 meters altitude in level flight and then climb back to orbit. While it's not a true landing, it's the closest you're able to get without abusing glitches, and a craft able to do this would also be able to orbit Jool from a true landing had there been a surface. However, there is a way to make a floating Jool platform and then land on it, the game will count you as landed. I suppose my point is that apart from glitch abuse (and sometimes not even then), this only goes one way - I don't believe there are many, if any, things that used to be possible in older versions that aren't possible now. Even with changes to the aero model or the physics of the parts, players have fought back with further aero and other optimization techniques. So I think it's definitely valid to evaluate missions outside of their version - I'd instead evaluate them based on what optimizations were used. A Tylo SSTO with no aero optimization at all is probably not possible, but if someone were to do it, that would be more impressive than a Tylo SSTO using heavy optimization.

Actually, I think all of these are possible as of KSP 1.11. Rapier/Nerv craft are quite capable. My personal best is eight: I've made a SSTO with 2/3 payload fraction - it can place two fully fuelled copies of itself in LKO. I don't have a link but with a 26.7 ton payload it weighs 40.05 tons at launch, so 13.35 tons of actual plane. This is trivial with DLC props. If that's not allowed then it's still possible by just spinning the craft. I've actually done this. In 1.11 there are still infiniglide glitches (although they were patched in 1.12) and Kraken drives can have as much acceleration as you want. I believe "moar ssto" made a craft that could SSTO both Jool and Eve in one mission. Regardless there have been SSTO missions to every body besides Kerbol, which is impossible. Technical KSP players have been able to squeeze a lot more out of KSP's parts than most people think.

5 degrees. Not sure whether that's optimal but that's the minimum angle snap available so that's what I used

@zolotiyeruki If you're still taking submissions, here's my entry for the Voyager division. This craft is basically a long range SSTO but with the nuclear engine removed. Since it's optimized for low drag and good mass ratio, it's actually quite good at endurance, even though that's not the primary purpose. Craft in VAB. 35 tons, six strakes. No clipped parts at all, no node offsetting, everything is attached how it looks. Laps 1-10 At this point the craft has been flying for over a full Kerbin day and has just over 38% of its fuel left, but the craft cruises higher as fuel drains, which means less drag and less fuel consumption. At this point I calculated that the craft could last for over 10 more laps, but that was a simple linear estimation. The true range of the craft is higher. Laps 11-19 Now the craft has been flying for two Kerbin days and done 19 full circumnavigations. I've tied the endurance record here, but I've still got some fuel left - let's see how much further this craft can go. Based on fuel usage I calculate here that the craft can definitely do four more laps and possibly a fifth depending on how much further fuel consumption can be reduced. So 23 laps is very possible. Lap ??-??

Is this challenge still accepting submissions? I'm thinking a slight modification of a SSTO I've made should be able to do a lot of runs around Kerbin. By the way I was watching Stratzenblitz stream his Goliath endurance run and he was using Mechjeb to keep straight. Also he has a pretty good computer.

Really? I feel like part nerfs or aero changes have more than been overcome by further optimization techniques. Are there any good examples of this?

Here's another potential Jool 5. Not low cost, low mass, or low parts - I'm going for low engines. I'm going to try to land on all five of Jool's moons using only one Rapier engine for the entire flight. Here's a preliminary image of what the craft might look like - I need to test some things still (The Laythe and Tylo landings specifically) but this will likely be pretty close to the final design.

No, but like swjr-swis said, recovery will be a bonus note next to your name on the leaderboard.

And here's my submission for the Single Stage Technical category. This is a previous version of my craft showing how I'm able to take off from the runway. I use brakes to let the Rapier spool up before starting motion, giving me the extra few m/s needed to not hit the water. Craft in VAB - 40,050 kg. One Rapier, one Nerv. I'm at 99 m/s when I run out of runway and the craft can't easily maintain level flight until 110 m/s so I pitch up to 9 degrees and barely pull out of the dive before crashing. After that, it's a pretty standard ascent to orbit. Accelerate until 1690 m/s on Rapier, turn on the Nerv, and point prograde until orbit. In orbit Detaching payload Proof of no drained resources 26.58 / 40.05 = 0.664

The payload fraction challenges were a nice way to squeeze as much as possible out of the stock parts in KSP, but they've all fallen into inactivity. Recently I've been playing around with efficient single stage craft, and I've been having a lot of fun trying to maximize the payload capacity. Also, since new optimization techniques have been discovered, I'm curious to see what the players can come up with. Categories Categories are arranged in two axes: -Type of craft (single stage vs multi stage, rocket vs plane). All else equal I expect multi stage designs to have an advantage over single stage designs. -Techniques used to design the craft (aero optimization) In my mind I divide this axis into three parts: Purist, Technical, and Anarchy. Purist: The craft must be physically possible. In other words, no clipping, unless that clipping is incidental and doesn't affect the craft's aero properties. Fairings are allowed if they don't clip through anything. Technical: Clipping is allowed, as well as node occlusion and root fairings. These crafts are still bound by the physical properties of KSP's wings. Anarchy: Any aero glitches are allowed. Stacked cargo bays, magic wings, et cetera. However, you must still use an actual engine for thrust - no Kraken drives. Score is Payload Mass / Launch Mass. The payload cannot have wings or engines, and all resources must be full. (Clarification - the resources don't necessarily need to be full as long as you can prove that no resources were drained from the payload). The payload must be separated from the launch vehicle in a stable orbit (Pe > 70). Leaderboard: Single Stage Multi Stage Purist camacju - 0.614 (Plane - reusable) Sival - 0.416 (Plane - reusable) swjr-swis - 0.22 (Rocket - reusable) pedter - 0.191 (Rocket) Sival - 0.340 (Rocket) Technical camacju - 0.676 (Plane) camacju - 0.664 (Plane) zacspace - 0.405 (Plane) Anarchy If there are any suggestions for categories or rules, please let me know!

I've got a few questions: -Are DLC props allowed? I'd like to use them for the initial ascent of my Eve lander. -Are we allowed to mine on the runway? If so, then recovered cost is only limited to whatever the disposable stages of the Eve lander cost. The biggest loss there will be Vector engines but total cost would probably be about 50000. (Or I might try to make an Eve SSTO??) Time won't be an issue because of recovery - I'd spam enough ore converters to mine the fuel within a day, and pack a level 5 engineer for that mining bonus. -Does the timer stop when the kerbal reaches Kerbin, or when the last piece of hardware reaches Kerbin? If it's the first, then I'd throw my Eve transfer stage onto a crazy orbit and wait the couple decades necessary to get the right gravity assists to slow down again, while the kerbal only takes a year or so to come back home.

I didn't see anyone going for a Mach 2 capable plane that also had long range yet... Contract 001A, Fixed Wing Scout/Science Aircraft Author: Me (camacju) Name: Plover Description: High speed, high altitude, compact science aircraft. Single Panther powerplant. Thermometer, barometer and atmosphere analyzer in hollow nose. Range: About 10800 km Gallery: Further screenshots: A possible SSTO version of this would swap out the Panther for a Nerv and Rapier, as well as adding a lot more fuel.

Attempt 3 at turboprop record: "Vega" reached a maximum altitude of 19249 m. This plane was really hard to control for the entire flight - I couldn't just let Mechjeb hold altitude; I had to babysit it the whole time. Probably due to bad air intake placement - those air scoops actually have a lot of drag. Maybe inline precoolers/nacelles are the way to go? In SPH Landing gear ditched at takeoff 18 km, drop tanks dumped soon after this 19 km Close to being called "19.3 km" - the engines didn't actually flame out here, meaning I had too many air intakes, but if I end up doing another attempt, I'll keep them since I'll definitely need them above 20 km. Just for fun I brought it down for a landing. Was quite easy actually - stall speed is absurdly low. Comparison to the first attempt - clearly they're related, but there are definitely differences. Still not as much wing area as @chadgaskerman's attempt, which implies further room for optimization.

Well, I added more wing area to my plane, and it went way higher than I thought it would - 18.3 km In SPH - similar to the other design, but I added more wings, reduced the number of intakes, and added two drop tanks. 16 km, still aggressively climbing. Drop tanks gone 17 17.7 km - there was a local maximum of altitude here, but pitching up solved it. 18 km - the engines are really struggling now. One engine flames out, leading to loss of control Maximum height 18.3 km

Hmm, seems like you have a lot more wing area than I do. I guess sailplanes really are the best way to go here... Also that craft seems pretty optimized already with the exception of the fuel amount. Lots of mk1 parts in stacks

New entry, this time with a pilot: In VAB Climbing 12 km 15 km 16 km 16.4 km max altitude

I'm pretty late to this challenge but here's an entry that can get to 16.3 km in level flight, and probably could get to 17 km with a bit more intake spam. In VAB On runway I hold a 20 degree climb until 13 km and then pitch down to 10 degrees At this point one of the turboshaft engines flames out, so I can't maintain altitude - if I attempt this run again I'll throttle down at 16 km. This craft has very low drag and a good lift to drag ratio so it can definitely make it higher. Edit - I didn't include a capsule, but with a proper cockpit it still could likely reach 16 km. I'll try tomorrow - I guess this is what I get for not reading the challenge carefully

I haven't done a space station in a long time - this challenge seems really fun

Without nukes it's hard but not impossible. Tylo orbital velocity is 2100 m/s, so let's generously say it takes 2250 m/s to land and to reorbit. The descent stage would have to get suborbital and burn back to orbit, leaving the lander to do the rest of the landing and go back to Tylo orbit, then both halves would need to do the 800 m/s escape burn and get home. Let's assume that the descent stage and lander have the same amount of delta-v, just for the sake of argument. Then, if the descent stage gives X m/s before burning back to orbit, it does 2X+800 and the lander does 5300-X. In other words, each stage should have 3800 m/s of delta-v, and the descent stage should give 1500 m/s worth of assistance before burning back to orbit. Here's an example of that. (Granted, this only seats one kerbal, but just scale it up if that's the problem) Not too hard to get into Tylo orbit. Here's another, with less TWR but more delta-v and less mass:

If you're open to using Mechjeb, you can turn on Smart A.S.S in SURF mode and set it to SVEL+, which is always going to be surface-relative prograde. That's what I do for SSTOs.