camacju

woah this challenge exists i might attempt a juno based mission

This is possible with sufficient abuse of propellers and magic wings (Stratzenblitz did it)

You should disallow action groups as well.

I actually had a serious submission in the works (very similar to OJT's most recent one) before I saw the message about root fairings, so I never finished it. I've been well. Doing some games other than KSP, but still playing. Right now in KSP I'm working on a tour of Lt_Duckweed's Quack Pack.

This challenge as-is is so ripe for exploiting that it's honestly a bit ridiculous. This seems like it's a game of who can get the closest to a 49999.9 x 49999.9 meter orbit and then who is the most patient. Also I've seen root fairings brought up here, so clearly aero exploits are on the table. I think I'm going to sidestep all the optimization of aero exploits and orbit height at once. In KSP, two parts can mutually occlude one another. Fairings, cargo bays, and engine plates can all occlude other parts, and by using two fairings or two cargo bays aligned perfectly (and I do mean perfectly; floating point errors are enough to break this), they will also mutually occlude, leaving a craft with drag of exactly zero. Engine plates are a bit easier, as when the engine plate is "closed" with a part on the bottom node, it will occlude all parts attached to its other nodes. This includes fairings and cargo bays, both of which can occlude the engine plate. This doesn't require precise alignment so it's much more robust, although a bit heavier. I think you can see where this is going. I'm too lazy to take this thing to Duna, and it doesn't deserve an actual rocket. So here's a proof of concept where I complete an entire orbit of Duna with exactly zero drag after I decouple the rocket engine. Any change in apoapsis and periapsis is entirely up to floating-point errors, so this truly is only limited by the stability of my computer. If I wanted to really abuse this, I would leave my laptop running for several days and use a macro to quicksave every few hours, so it could persist through crashes. I don't intend this to be an actual submission. Rather, I want to call attention to the fact that submissions here aren't really in the spirit of winged aircraft range. I have a few ideas for modifications to the rules: -Start from a stationary point on Duna's surface. It could be standardized to a certain lat/long, or maybe we could be free to select our favorite mountain peak or something. -Start the distance meter when altitude crosses X amount from above. This is abuseable with my above video, but you can easily say something like "at least one wing part needs to be producing drag at all times" so our planes have to actually be planes. -Disallow fairings, cargo bays, and engine plates. This is the lazy solution and it'll still degenerate the challenge into who can get the closest to space without actually being in it.

227160 funds with tank, 175960 funds without tank, 611 funds per ton of payload. First stage is 7 Clydesdale Second stage is 1 Rhino (4x Poodle is probably even cheaper) In testing I managed to bring a few more tons of payload to orbit with a better ascent profile, but this is still pretty good

Ok, this is probably as optimized as I can get my previous expendable launcher. 287520 funds with fuel tank, 236320 funds without fuel tank. This is just about the lowest that I thought this design could go. Six Clydesdales, seven Twin-Boars, the outer six are dropped once suborbital and the central one circularizes. Warped to the day side, showing propellant and full fuel tank. Counting the bit of unused propellant as payload, this craft brings 293 tons of payload into orbit for 236320 funds, for 806 funds per ton. This is probably beatable by switching engine types, which I will attempt.

I'm gonna put this placeholder submission here, I've since done better than this but I am not quite finished optimizing it yet. I know that SRB + Twin Boar is a good cost per ton combination. Not sure what the best ratio of solid to liquid fuel is however. The cost of the S4-512 is 51200 funds so the cost of the launcher is 292310 funds. Note the lack of nose cones. Large rockets don't need them as much because of the higher thrust. Launch, immediately pitch over Core throttles down otherwise it'll go too fast in the lower atmosphere SRB burnout, apoapsis is above 70 km SRB separation Circularization In orbit. Note that I actually have more than a full Twin-Boar's worth of fuel left here.

Are ram air turbines allowed to generate electricity? You wouldn't be getting any "free" energy from it, since it uses your plane's forward motion to generate power and creates drag.

There’s actually a surprising amount of room for improvement still. The only records I consider untouchable are Brad Whistance’s Jool-5 in six tons, and maybe his 2 ton Moho mission, but even these might have mass shaved by more gravity assists. Everything else is very beatable. (I actually have some craft “in storage” that break a low mass record, I just haven’t bothered to fly them yet). Lots of physics warp and also running the propellers at a slow speed, which lets the blades briefly shield each other from heat. Takes a lot of attempts though. You can use this trick to land on every body besides Laythe, Tylo, and Eve with just the EVA pack. You’d put an inflatable airlock into the “magic hand” storage, and then climb in to refresh the EVA propellant. It’s quite a bit too exploity for my taste however.

I suspect sub-2 is possible just from flying this existing craft better. I do have ideas to go significantly faster however.

I took the More Boosters approach all the way, with a time of 2:04. Here's the full video:

One thing that I've noticed is that for both Rapier-only ssto craft and Rapier+Nerv craft, I use approximately the same amount of liquid fuel in both the jet and rocket phases. For a Rapier-only craft, that means I consume oxidizer during the rocket phase which eats into payload mass, but also I have a lower dry mass which means more payload mass. However, the additional dry mass of the nuclear engines is more than compensated by the reduced fuel consumption. This can be seen intuitively, because the mass of oxidizer used is nearly always going to be less than the mass of the engines. (Otherwise you've got way too much engine for your craft's mass). We can use an example craft to demonstrate: This plane is 109.5 tons on the runway, and is powered by three Rapier and two Nerv engines. It has 3800 liquid fuel, nearly all of which is used to place 75.1 tons of ore tanks (can be replaced with other payload) in low Kerbin orbit. Based on the rule of thumb outlined above, this means it uses 1900 liquid fuel in the jet ascent phase and 1900 liquid fuel in the rocket phase. Basically, the plane itself is 34.4 tons, the payload is 75.1 tons, and this is just about the maximum mass that can take off from the runway for this number of Rapier engines. Now we can consider the effect of removing the Nerv engines, which are three tons each. This reduces the plane's mass to 28.4 tons. However, now that the 1900 liquid fuel in rocket phase must be combined with oxidizer, we must add 2322 units of oxidizer to the plane, or 11611 kg. And that's not even counting the dry mass of rocket fuel tanks, which is worse than the Mk0 liquid fuel tank. This extra fuel tank mass will eat into payload fraction and ultimately reduce the capability of this SSTO. Note: This analysis is purely for payload capacity to low Kerbin orbit. If you plan to go further than this, then Nerv engines are advised, and you might as well use them on the ascent and save on the 11.6 tons of oxidizer.

https://cdn.discordapp.com/attachments/523675813217042465/1040140904729681940/image.png

I was actually planning to do at least one quack pack landing in this mission but I felt burnout coming and decided to end the mission early. I do absolutely plan to make a Quack Pack showcase in the future though.

grand tour but also jool 5

https://www.youtube.com/watch?v=nbuMsM8W6fw https://forum.kerbalspaceprogram.com/index.php?/topic/210544-stock-system-grand-tour-in-144-tons/

Hello everyone! The capstone of stock KSP missions is the “grand tour” - landing on every planet and moon in the Kerbol system. (You can technically land on Jool but that’s not traditionally counted). A single launch grand tour is a feat of precision engineering, careful mission planning, and the dedication to actually fly fifteen landings and return safely. The first mission I'm really proud of was a grand tour mission (which was also my first ever Eve return), and I posted an album of it on this forum. The mothership looked something like this: And this was the entire craft: Like most grand tours, this is a very large rocket, and I completed this mission mostly through pure brute force. I did use some gravity assists, but this rocket absolutely conforms to the "More Boosters" philosophy more than anything. This was done in October of 2020, shortly after I started playing the game, and you can see that in the distinct lack of optimized craft design. But that was two years ago, and since then I've gotten much better at craft optimization, gravity assists, piloting, and the game in general. Probably the best example of this was the Eve lander of this early mission, which looked like this: It’s a pretty large lander and way overbuilt for Eve, but it got the job done. And then a while ago I did a 7.5 ton Eve mission, which I later cut down to just under 7 tons. This is still the record for lowest mass kerballed Eve return without abusing “magic wing” type glitches, even without ISRU. It gave me an idea - since this Eve lander was so much smaller than my first one, could I make a grand tour mission, but this time putting a special focus on minimizing mass? I first started thinking about a minimalist grand tour in February of 2022, but exams prevented me from doing much more. I revisited the concept in June, and managed to cobble together something vaguely resembling a craft - but I was occupied with graduating college, and it never flew. Here’s a picture of it anyway - it is similar in concept to my final design: This was only part of the final craft, and was already projected to be much smaller than my previous grand tour - at the time I estimated a final mass of around 20 tons. As far as I’m aware, this would still be the lowest mass grand tour ever, as the lightest I know of is Brad Whistance’s 25 ton craft which made heavy use of ISRU. But this was unsatisfying - I was still leaving a lot of mass on the table. My original grand tour mission used Mammoth engines on the first stage. I wanted to have the mass of my entire craft be less than the fifteen tons of a single one of those engines. About a month ago, I finalized the design of the craft: 14.45 tons - well within my mass goal of 15 tons. As you’ll see, I could have pushed this even lower, but I chose not to because I had already met my goal. A breakdown of the craft design is below. I made a video showcasing this mission, also. I've put my comments on it (time stamped) in a spoiler box below.

If you're open to installing mods, there's a mod called Trajectories that will show you what your aerobrake path looks like based on your craft's aero characteristics.

Actually, no - the limiting factor is torque per mass, rather than top speed. Reaction wheels provide a lot more torque than the Breaking Ground rotors - with normal elevon props, the rotors can't even reach 300 meters per second. The lift to drag ratio is just too low. One interesting compromise would be using reaction wheels to spin a Breaking Ground rotor and provide more torque this way, but I haven't quite worked out how the control scheme would work yet.

I approve, mainly because I enjoy gravity assists!

After my low mass Eve mission, I've wanted to try another mission where I minimize mass. Also, my previous grand tour didn't sit quite right with me as it was extremely unoptimized, especially with the Eve lander. Additionally, I don't know of any low mass grand tours other than Brad Whistance's 25 ton grand tour from a long time ago, which used ISRU heavily. With some slight changes to the Eve mission, I cobbled together this 14.4 ton ship: Tipping the scales at 14,447 kg, this is by far the lightest grand tour attempt that I've ever seen. (If someone knows of a lower mass attempt or other low mass attempts, please let me know - I'll probably suffer a lot trying to reduce mass further but there are still savings here.) The craft consists of seven distinct modules: launch stage, four dedicated landers, fuel tanker, and ion tug. Here's the craft with the launch stage removed, so you can see how it all fits together. I've started flying this already, but I haven't made it very far, so I'll probably wait to post an update on it.

This reminds me somewhat of the 100 EC range challenge, where it was demonstrated that you can fly basically forever on a single Z-100 battery. As an aside, will we be allowed to use a turboshaft engine if no liquid fuel is consumed? My plan is to use one as a ram air turbine - have it passively spinning so its alternator will generate electricity.

For the record, HoDeok was able to get a craft stable in the "Landed at Jool" state by transferring a craft in the landed state all the way to Jool. Notably, this effect will transfer between crafts - a craft landed on an already-landed Jool platform will also be landed. So you can indeed get surface science from Jool. Likely this is what the OP was thinking about, but it's a pretty niche mechanic and I don't fault everyone here for not knowing about it. Edit: Apparently they were thinking about something else entirely. But the challenge is definitely possible, if a bit tedious.

I use either 0 or 5 degrees because I'm too lazy to install a precise editor