gchristopher

Even without intake/wing reuse, you can get better than 66% payload fraction on a spaceplane with ridiculous airhogging (~1 intake per ton). Intakes are pretty much the only factor in max lifting ability. But the time investment would be pretty extreme. That's a lot of time creeping up in altitude while maintaining velocity while keeping your thrust 150 mm/s over atmospheric drag. Part count might hurt more than tonnage. I've lifted 100 tons payload on a 150-ton spaceplane with 160 ram intakes, but that's one tiny strut per intake, so the air alone was 320 parts.

This hydrofoil topped out at 145 m/s while carrying a rover as cargo. It was dropped off by a VTOL for an amphibious challenge. Here's all I know, stolen from other, better, boats: - only have low drag aerodynamic parts underwater, the bounding boxes determine buoyancy. - don't have any part come into new contact with the water while running (I use physics-ignoring small hardpoints for the risers) I had to fiddle with thrust, CoM, and angle of small control surfaces under the water before it'd stay level at speed. It doesn't corner well. It flies very poorly. Nosing up even slightly will launch 2000m in the air to its death. 200 m/s should be very doable with a little more thrust/drag.

Yep, the STK software is commonly used by Universities and amateurs to plan satellite missions. Even planning an orbit around Earth has a lot of details to consider, all needing good orbital calculations. Your power budget will likely depend on ability to keep solar panels aimed at the sun, when the sun is available. Magnetic attitude control systems need to know how your orbit will interact with the Earth's magnetic field. Thermal modeling is a huge issue, so you need to know how long you're in sun and shadow, and an estimate of how much radiation is coming from what direction. That's one area where we get really lucky! It turns out that if you toss a small lump of aluminum, fiberglass and copper into Low Earth Orbit, without much in the way of active thermal management, it tends to stay within -40 to 120F, where electronics mostly keep working. A typical cell phone will probably continue to function in space (except for the display) as long as you strap on a heater to the battery and some solar cells. There's actually been a couple satellites built around that cheap idea, not sure if any like that are in orbit right now. That's all stuff that's way beyond KSP, but will be components of a real-world mission planning software suite.

What about systems that use aerodynamic lift? The design would be a pain, but payload fraction can approach 70% (with preposterous airhogging), and with wings and intakes reused, maybe a little better is possible for a Matryoshka doll lifter. edit: Huh, guess you don't even need the wings. Wow.

If I understand the KAS mod right, it gives you an adjustable length flexible tether with the option of being docked or undocked. If "undocked" works the way I think, the two connected vessels would retain separate centers of mass. It reports some kind of force on the cable. It'd be neat to see if that corresponds with expected tension generated by a gravity gradient.

Oh great! I was hoping that'd work. Maybe try a KAS tether? It'll lose orientation once the object goes on time warp rails, which forces a stop to angular rotation.

Doesn't break any ground that anyone else hasn't covered, and a KAS winch is actually a worse deal than an external seat (both mass and drag), but Jeb insisted... 12 RTGs, 2 swept wings, 2 small control surfaces. A bunch of fuel on drop tanks. 2 Delta wings on the outermost fuel stage. It has problems with tracking due to no vertical stabilizer. Trying again with one more small control surface so it keeps a heading better.

I don't recognize a lot of the parts, but Starfish looks pretty cool! You know, you could have an awesome finished entry in two more flights, Fengist.

What Goes Up, LLC. A lot of people might say "we don't have a semblance of a plan," but here at What Goes Up LLC, we call that "Versatility!" We offer both our sincere apologies in advance, and as usual, completely disclaim any liability for our newest multifunctional ship: Square Peg Statistics: All stock parts, plus MechJeb. Mass: 19.09t / 10.65t dry 112 parts TWR: 0.64 dV without attachments: 1173 m/s atmo, 4267 m/s vacuum RCS dV: 59.5 m/s Crew: 4 Fore and aft 5-port (1 sr, 4 regular) docking structures.

Oh, wait. I am reading back through more posts. I see Sirine's shuttle landing was awarded the points? Hmm, I see the shuttles attached to the station, but can't find a picture of how they were launched. (But I can find an argument about what a shuttle is.) Maybe wasn't necessary to set up the preposterously complicated model of the NASA Space Shuttle? I dunno, it seems like the main challenge is strapping a plane to the side of a giant fuel tank, intentionally setting up your CoM at weird angles to your engine positions, and trying to get it to actually make orbit.

Well then, let's get closer to getting this train wreck underway! So, is this a "Space Shuttle?" Here's what it has going for it in terms of "Shuttle-ey-ness": - Vaguely recognizable as a Space Shuttle. (Won't have an openable payload bay with stock parts, but roughly the same shape) - The only liquid fueled rockets are the ones attached to the shuttle. Only solid rockets are attached to the external fuel tank. (6 are needed for adequate dV scaling, but the design is equivalent.) This necessitates that the shuttle main engines are angled to sort of aim toward the center of mass. (This is the most horrible requirement, and where most shuttle-builders seem to cheat to get around the insane center of mass locations.) - The first stage is the main engine + boosters, subsequent stages are just the main engines. - All stock, with MechJeb only for the readouts. Not remotely flyable by autopilot. Here are the major points against it: - The main engine angle is way outside of the engine's gimbal range, so a second, forward-facing rocket engine is used for the final insertion and deorbit burns. I don't think the above contraints are achievable otherwise. - The biggie: I added two jet engines that are used ONLY to assist with landing. The thing has a roughly 5:1 unpowered glide, which is about as crappy as the actual space shuttle! However, the actual space shuttle lands at much faster speeds than the KSP physics engine will support safe landing, KSP parachutes don't work to decelerate on the ground, and without FAR, landing in a true aerodynamic stall is impossible. Stock KSP really isn't up to simulating a true "shuttle" landing. I think making it land like a Kerbal spaceplane, under minimal power, could be considered a reasonable compromise. Performance: - It is miserable to control during ascent, requiring a mixture of careful thrust adjustment, tons of SAS torque, aerodynamic control surfaces, and on-the-fly fuel rebalancing to get the 18t payload to orbit. It's one seriously wobbly haphazard gravity turn! - After the awful ascent, once the external fuel tank is detached, it is just a normal KSP spaceplane with poorly placed wings and lots of useless cosmetic bits to make it look like the Space Shuttle. For the purposes of the Versatility Marathon Challenge, is this a Space Shuttle? How about this one I made out of gingerbread?

Err, that's not how I read it. I think Sensi actually launched that monstrous SSTO rocket 9 times. See how each satellite has 3 of those 3.4t RCS fuel tanks? I think the picture was of one satellite, and on the third picture, it says "repeat 7 times." So there were 8 satellites and the rover, each launched on a separate huge SSTO? (wow) Yeah, I think that was 9 giant SSTO flights. You can see them all assembled into a moon ship later. My main question was whether I could use a SSTO rocket and get the SSTO points, mostly because a spaceplane ascent takes so much longer. I can do either, but I'll take the easier option if they score the same. p.s. Wow, awesome mission Sensi

Sorry for so many questions! I see that you gave Sensi 90 Master of Aerodynamics points for a rocket SSTO on Mission 1. Not a big deal either way, but I'd hope to compete on the same rules as earlier entries. Maybe if people have already scored the 10 points for a rocket SSTO, add another few points for making it a spaceplane and landing at KSC to the rules?

Thanks! I was confused because the Master of Aerodynamics bonus doesn't specify that you have to bring it back to KSC. So, would these be worth the same? - a launch using a vertical-take-off rocket SSTO that doesn't use jets and lands back at KSC - a runway-launched SSTO spaceplane that lands back on the runway? i.e. do both earn the 10 point Master of Aerodynamics plus staying eligible for the 5 point Jet Engines are for Planes mission bonus? Or by Master of Aerodynamics, did you mean to limit it to SSTO spaceplanes? (That would make more sense, because SSTO spaceplanes are a lot more involved than SSTO rockets.) It makes sense that a true "Space Shuttle" style lifter would be worth a big bonus. Asymmetrical lifters with wings taking off vertically are really hard in Kerbal!

I have a couple questions about the general scoring: is the "Shuttle Missions" goal satisfied by launching everything from the runway onboard a spaceplane, then landing the spaceplane at KSC? (i.e. does it have to launch vertical attached to a rocket to be a "Space Shuttle" are we just saying it just needs to be a reusable spaceplane?) Can you get points for both "Shuttle Missions" and "Master of aerodynamics" or is it assumed that a spaceplane needs to be a SSTO? Same question for "Jet engines are for planes." Is that cumulative with either of the other two bonuses? I have a fair selection of SSTO's lying around from the Affordable Space Program challenge, but I'm considering trying to scale up for bigger missions like this challenge requires. Here's a prospective core craft and lift system. I think the core craft is pretty close. It's 17.125t, 10535t dry. 5 crew pods, a claw as the main forward attachment, docking port sr. on the bottom. It has just under 3,400 dV, so no problem for the Mun test run. It's heavy on reaction torque, assuming it'll usually be attached to things, but that might introduce wobble on the docking ports, so that might need to change. I'm a little concerned about its weight, getting it out of Eve's gravity well won't be fun. The spaceplane isn't named yet, but it's a SSTO that successfully took 100t to LKO, mostly by dint of spamming intakes. It'll need to be tuned and have intakes moved to non-clipped locations before it's fair to use. Also, it crashed on the first landing attempt, but I think that was just the CoM moving too far back from fuel usage in combination with the insane lift and thrust ratios once the payload is gone. Hand-adjusting the fuel position, or maybe TAC or PWB fuel balancer, should fix the landing problem. (Or add radial thrusters to the nose to keep it from bouncing off the runway.)

Yeah, this is one of those "learn what you're doing and do it again, better" sort of adventures. In celebration of sirkut getting the excellent Infernal Robotics plugin working in 23.5, let's re-do this challenge faster, dangerouser and Kerbally-er. Seems to have made the wheel/deck problem I was having go away, too. Let's go VTOL, deploy the boat from a hover without landing or parachutes, and let's crank up the max speed on that boat to 145 m/s! What could possibly go wrong? None of these ideas are original. I've seen other people do everything presented here at various points in other posts or videos. But they worked out nicely, put together into a VTOL plane, hydrofoil and rover. What Goes Up, LLC. Sub-Bureau of Extremely Hazardous Vacations Presents: Aquatic VTOL Shenanigans

It's your challenge, maybe try it and post a demonstration before asking other people to do it? Aww, don't be a meany-head. Kasuha didn't do the separate boat/rover thing, but nobody will want to do the challenge if you smack them down over details that really aren't central to the challenge of making an amphibious plane/boat/rover combination. Okay, moving on! What Goes Up, LLC. Unjustified Personal Travel Division Presents: Jeb and Bob's Island Holiday This is a 3-part craft: floatplane, air boat and rover. The floatplane is all stock and uses empty Mk2 Fuselage as floats. (Empty ones have dramatically less drag and the same buoyancy.) It can land with payload, and take back off both empty and with the payload still attached. Keeping the stall speed well under 40 m/s helps with all that. I didn't fiddle enough with float position vs. center of mass so small radial rockets help get the nose up enough to launch from the water. The boat is a basic hydrofoil with flat passenger decks and a rover bay. It's pretty stable in the water up to 50-60m/s. I wonder if adding some control surfaces might help stability at higher speeds? The boat can either be deployed after landing, as depicted above, or by airdrop with parachutes. Both work fine. It ended up being more amphibious than intended, just to make deploying the rover simpler. Retro rockets allow it to back up, but weren't used. The rover has wheels. And rollbars and a spoiler, cause Jeb helped. KAS is used to reload the rover, because I'm not sure that driving on ramps and flat decks are feasible with stock 23.5. So yep, flew over near the island, dropped off a boat, deployed a rover off the boat, planted a flag, put the rover back on the boat, and boated on back to KSC. Thanks ihtoit, that was fun!

Does anyone have advice for getting the "rover drives on a flat deck" part? If I make a ramp out of wing connectors or structural panels, what I'm seeing is that ruggedized wheels bottom out their suspension without lifting the rover, and don't seem to exert friction force on the ramp. Small gear bays don't show the same suspension failure, but are unpowered. A ramp made entirely out of girder segments seems to work better with wheel collisions and friction, but driving over several segments seems to encounter weird collision box issues, and tends to spontaneously throw the rover into the air. Is driving on ramps feasible in 23.5?

Thanks, and no. I guess in theory they could be used that way, for some kind of weird VTOL-assisted landing? But no, SporkLift is dead weight. Typically I drained off the fuel into the orbital transfer tug along with payloads, so SporkLift doesn't contribute any fuel or oxidizer to the deorbit either.

Yep, this is hard. Everything within 2.3 km is still subject to physics simulation and can be switched to control, but farther than that, it goes to "on-rails" physics and will vanish as Rakaydos describes. It is possible to have a reusable first stage if you find some way to preserve/land it in some combination that also gets subsequent stages away safely. One possible scenario might be to launch nearly vertical then separate stages. If the second stage has a high enough TWR, you might be able to accelerate it fast enough that you can switch back to the first stage, land it, then go to the tracking center and take control of the second stage before it reenters the atmosphere for a circularization burn. Re: Discussion about different scoring systems: Since this challenge is all about exploring neat designs that might matter in a future version of an unfinished game with regards to a economics that don't exist yet, pretty much any scoring system is going to be speculative and premature. I think it'd be okay to present attempts in the order completed, like the K-prize, or maybe try to categorize them? The real point is: A. You did it. This thing is HARD. B. Whatever interesting/fun bits you discovered/created along the way. I see SirJoab has already added little highlights of what each person did to the first post. That was going to be my only suggestion to change! Kasuha's system of chaining docking ports to create a flexible fuel line/anchor to align payloads with the VTOL lifter deserves a mention. Jasonden presented the first VTOL lifter to not use jets. (With the million 24-7S engines) 1greywind boasted a quick 22 minute fastest mission turnaround (wow) that must have made those 12 missions a lot less tedious.

Hot Dog Bun (full writeup, craft files) is completely symmetrical SSTO spaceplane that splits right down the middle. Each wing half attaches to the side of a payload in orbit. Then the whole thing deorbits and lands at KSC. It's all stock. Now that the claw is in the game, refueling is stock, too. It flew 6 missions for the Affordable Space Program challenge, refuelled on the runway and relaunched each time. Ground assembly/disassembly is possible because the plane has two sets of landing gear, one facing forwards and one sideways. One is used for takeoff/landing/taxi and the other is used to move the wing halves in and out of a docking connection. A single sideways-facing powered wheel drives it when going sideways. A couple systems using a VTOL launcher to lift a payload and a spaceplane to deorbit were used. This was the second, more powerful, iteration.

Caterpillar truck is waaay better!

Nice, LordFjord! I'd been trying to figure out the same thing, and run into roughly the same analysis before I ran out of attention span and wandered off. I glanced at Fellow314's craft. 104 ram intakes and 6 circular intakes. My understanding of that approach is that you get to a high enough velocity, then creep upward in altitude until apoapsis gets up out of the atmosphere, then fire nukes to raise PE. Seems like once you get to high altitude, thrust/drag is the dominant factor, and intakes are all that matter for thrust? Have you tried a claw for payload holding instead of the large docking port?

Wow, thanks for the encouragement and appreciation, everyone. When I started this, I couldn't reliably launch a spaceplane, so I learned a lot from other amazing entries. What a journey. Oooooh! I can't wait to see it! 6-7% payload is the best I could estimate getting from a pure rocket in my halfhearted attempts. I'm glad someone else is doing it, maybe I can make myself stop trying now. Yeah, sadly, the giant wheels are far too fragile to actually use as giant wheels. Don't give up and hyperedit, though! I had to build a lot of weird heavy gantries and I settled on a stock way to deal with the problem you're seeing. You can use small gear bays to cushion other wheels from crushing forces. That fuel truck weighs 535 tons and has only 8 of the ruggedized wheels to drive it around. It's pretty slow, but corners nicely. Plus, with the claw, you might be able to avoid using KAS if you want to stay stock now. Good luck! I look forward to seeing it.

Faster that my Kerbals can say "rhobicuboctahedron"*, the station is finished! That was a huge challenge, wow. (* very slow, none of them can pronounce that.) What Goes Up, LLC presents Orbipalooza: Fuel Depot, Intermittent Science Station and TOTAL Concert Venue! The station is in 260x260 high Kerbin orbit. (It's a concert venue, so of course it had to be in "high" orbit.) Three different 100% reusable lift systems were used to build and crew the station, comprising 5 vehicles. 9 missions were flown with cargo ranging from just passengers to 39.85 tons. Everything that launched used only stock parts plus Mechjeb. TAC Fuel Balancer and Docking Port Alignment Indicator were also used extensively to save effort. Ground operations used Infernal Robotics and KAS for gantries. Full writeups of each launch system are over on the rocket builder forum and most were already described in this thread. Here's the mission log: Launch Vehicle: Up Chuck Mark XXXIII / Unladen Swallow Mark XXIII (writeup, craft files) : These were the first successful try at a composite system where a VTOL rocket/jet lifts the payload, then a spaceplane retrieves, deorbits and lands the rocket portion. The rocket is then righted and moved by a gantry, the next payload attached, refueled, and launches again. Mission 1: "Atomic Sisyphus Mark VII", Mass 22.702t. This is the orbital tow truck that will haul station modules up from low kerbin orbit to a higher orbit, and do some RCS assembly work. Mission 2: "Science or Else" Science Core and YIKES Escape Pod Cluster, Mass 23.066t. Each "Yikes! Individual Kerbal Escape System" consists of a pod, engine, fuel and parachute, enough to get one Kerbal safely back to the ground. The cluster includes 12 pods, enough for the 8 planned crew and 4 guests. At this point, enough had been learned from the composite launch system to scale up to a better system. Launch Vehicle: SporkLift Mark IX / Hot Dog Bun Mark XIV (writeup, craft files) This system features a flatter, brick-shaped rocket that can accommodate a 40 ton payload with fewer restrictions on shape. The spaceplane portion consists of two wing halves that split and attach to either side of the rocket to deorbit. One bonus is that the rocket lands upright on landing gear, so it doesn't need a gantry to right it and can drive straight to the next launch. Mission 3: Main docking junction, extra fuel and "Alaska Mosquito Mark I" RCS Tug, Mass 39.85t. Mission 4: Rhombicubeoctahedron superstructure base section, Mass 30.04t This had ungainly aerodynamics from using wings as station structure, had to drop the tonnage to launch successfully. Current station mass: 114.685t Mission 5: Superstructure upper section and docking port scaffold, Mass: 39.245t. This one had MORE weirdly angled wings. Why did it fly better than the previous mission? The internal scaffolding that held the round superstructure together for launch is pulled out once in orbit and becomes a large structure with several docking ports for visiting ships. Current station mass, 150.449t. Mission 6: Cupolas! Did you know that cupolas have a dragginess number of 0.4, twice that of any other pod? I don't know what that means, but it sure did crash a lot of trial launches! I hate cupolas. Hate hate hate. The only thing I found that would work was to build a "lampshade" shaped scaffold that dangled the cupolas around the rocket down near the center of mass, so they didn't drag the front of the rocket sideways and crash it. Then when I got the whole mess up to the station, the Alaskan Mosquito RCS tug was just a little bit too big around to place the cupolas onto their final location on the superstructure. Total fail. Cupolas are evil. I could only launch 4 at a time, plus some fuel. The launch mass was 30.745t, so sometimes drag is more significant than mass for this launch system, it seems. Mission 7: This is the Same thing plus a strut attachment so the RCS tug can actually reach the right spot. This only kind of worked. The little extender arm let me place the cupola, but both SAS and Mechjeb couldn't handle the wobbles and had large oscillation feedback problems. I wasn't able to reliably place a cupola with the right rotation. Mission 8: "Alaska Mosquito Mark IV" and "Combustible Camel" reusable fuel module. Mass: 36.987t. This mission delivered a claw-based RCS tug, which worked great. It was still a major pain to grab all 8 cupolas, move them around to the correct side of the station, then attach them. But it worked, the station is now fully assembled! After each launched, I'd siphon off the leftover fuel into Atomic Sisyphus, so there was usually a net gain of fuel each time a payload was shuttled up to higher orbit. The final station mass was 228.784 tons, after getting rid of all the temporary scaffolding that came up with the cupolas. Time to send up the crew! At this point, Jeb reasserted his majority ownership of the company and insisted on flying the mission and that it had to be a "sweet ride." So, we designed a maneuverable, aerobatic spaceplane with plenty of external seating. (All my Kerbals vastly prefer to ride on top.) We couldn't think of a good name, so we put up a poll on the internet to let people pick their top choice. A write-in candidate won by a large margin, so we went with it. Launch Vehicle: "Crew-Only, Liquid Boosted Exoatmospheric Reusable Transport" (COLBERT) SSTO reusable spaceplane. It features two RAPIER engines, awesome external seating for 8 passengers and a claw for flexible docking options. Mission 9: 8 Kerbal crew to the station, and Jeb showboating in his fancy new spaceplane. Mass: 8 x whatever a Kerbal weighs. (90 kg each?) After all the missions were done, the various reusable launch systems were driven a few kilometers away from KSC and parked to reduce lag. Here they are posing for a family portrait, ready more launches! Part count was definitely more of a limiting factor for the station than mass. At 718 parts, it was starting to lag even on my desktop machine. The superstructure panels accounted for a lot of parts. If I had to do it again, I'd want RTG's instead of all the small solar panels just for the lower part count. Ladders were the biggest sacrifice, so Kerbals have to use RCS to get around most places. Ever since I decided to go with a station shaped like an Archimedean solid, the complexity really got out of hand. Each panel is separately dockable, though most went up together with a support structure. The attempts to launch them as stacks of panels were hilarious slinky-shaped crashes. Everything that remotely involved a cupola found some way to be horrible. Okay, scoring. It's too bad tonnage is such an overwhelming factor. I was going for complexity, and the mass kinda just happened as a side effect. Module count is the hardest part to figure out. There's maybe 20-ish separate parts that were moved and reconfigured during station construction, and over 50 separately dockable pieces. I think grouping them together by function sounds fair, though. How about this for a module list: Atomic Sisyphus Mark VII Orbital Tow Vehicle Rec Room, Kitchen (Science Lab) and YIKES Escape Pod Cluster Main Superstructure (Rombicuboctohedral Panels and Crew Cupolas) Docking Junction and Docking Port Tree Alaskan Mosquito Mark I RCS Tug Alaskan Mosquito Mark IV Claw-Based RCS TUG That's: 6 modules, 228 tons, 8 crew, 9 launch/refuelings. All the vehicles and station (anything that left the ground) were stock, but the ground vehicles variously used Infernal Robotics and KAS. MechJeb, Docking Alignment Indicator and TAC Fuel Balancer were used in flight, but every maneuver was first done manually, without any mods, to make sure it was doable. I think multi-port docking is the only part where Mechjeb would be required to call it "reliable." Thanks for the awesome challenge, SirJoab! I've had a great time doing it and looking at all the other amazing entries. I can't wait to see more!