How do you design?

[Fett2oo5]

I'm wondering how people design a variety of things.

Rockets - When I design a rocket I more or less build the rocket under the payload until I get the Delta-V I want in each stage. If I am creating complex fuel lines, for "asperagus" staging then I might sketch it out on paper first.

Base - I recently started designing and building a Base, for which I sketched out what kind of structures I wanted (but not parts) then experimented with building in both the SPH and VAB. Getting the structures to line up for docking was tedious, I wish there was an easier way.

Spaceplanes - When I attempt to build a spaceplane, it's trial and error, and 90% of the time it's error. I'm horrible at designing spaceplanes, I wish I was much much better.

Space Station - I have yet to design a space station.

Refueling / interplanetary - I've yet to design either of these. I've just built an extra large rocket with a stage that was docked so I could meet up with it in orbit after a landing.

So I'm wondering, how do you guys plan, design and build for your missions. On the fly in the building? paper sketches? spreadsheets? part lists?

I ask because I hope to learn from any advice you might have.

Edited February 5, 2014 by Fett2oo5

[Tw1]

I tend to start with a concept, then play around with the parts I need in my imagination.

Then it normally gets completely revised in the VAB or SPH.

I tend to install bases in one huge go, rather than doing any fiddly docking. Then, it's a case of following my imagination, and knowing some shapes are easier than others to build rockets around.

For me, lifters are almost always 100% function over look. I always use parallel, or asparagus to avoid lifting extra engine weight. Everything on the lifter section will be firing at launch.

Desing is a very fluid thing though. It's rarely a simple process- we learn from mistakes, take precedents from things we've made before, borrow other ideas... It's alway complex.

[blizzy78]

Personally I love to design as I go along, refining as need be. Same with programming

[capi3101]

Rockets - I start by defining what I want it to do. I then look at the delta-V map and figure out how much delta-V will be required for each section of the mission. I carefully calculate the mass of the mission payload and equipment, and then run the Rocket Equation backwards to determine how much fuel I need. If it turns out I don't have enough thrust for the resultant weight, I redesign until I'm golden.

Spaceplane, same deal. The rules are somewhat different of course - I go with a turbojet per twelve tonnes of plane, a pair of swept wings and a pair of small control surfaces per six tonnes of plane, a Ram intake for every tonne if possible, and a Mk2 Fuselage per turbojet.

Interplanetary I like to do in segments. Send up a transfer stage, a supply stage if necessary, and a payload stage then dock them all in orbit. Once again I make sure I've got enough fuel for the job before I head out. That's not HOW you have to do it, but it is helpful for larger payloads.

Space Station - easy. You really have to ask yourself why you want a space station. Once you know why, it's like building an interplanetary ship. Depending on where you put it, you might not need so much delta-V.

Bases I haven't really delved into yet. They're kinda ill-defined, though; a base is pretty much as you make it. My Mün base has a habitat lander and a bunch of rovers laying around.

[Skorpychan]

I work the design over in my head a few times, then finally pull up KSP and knock it together in the VAB. Then wiggle it around when it encounters the harsh light of reality, to make sure it works.

Then I add the usual gubbins. Lights, docking ports, mechjeb, etc. Finally, I strap a lifter under it, and send it to the launchpad.

Then I pull it OFF the launchpad, work over the action groups, redesign things, add what I've forgotten about, then send it back to the launchpad again.

Then I launch it. If it's tricky to fly, I launch it again and again, with occasional redesigns, until the lifter stops exploding on the way up.

[Rusty6899]

I will generally get a feel of how the mission will be undertaken; how many stages do I think I will need? which engines will be most appropriate for each stage? how many bodies will I be landing on? can I reuse the lander? etc.

When these questions are answered I turn to my spreadsheets to ensure I have a 5-10% excess in delta-V budget for each stage (more in an interplanetary stage where I may not have a fully equatorial orbit, or landing on, say, Duna, where I am unsure how much of the breaking will be done by parachutes and how much by engines). For complex procedures (e.g. where I will have to assemble landers out of several sections in orbit, or if I am using parachutes on a fairly heavy lander, I include a testing stage to ensure I don't end up on the other side of the solar system with a strut preventing a docking port from opening, or with no way to land a craft).

I would say it is a case of Concept Design, Detailed Design, Testing.

I definitely need to implement a structural design stage within the concept design, though, as I have fallen foul a few times. It's frustrating when a complex mission is designed well, but it all fails because your craft falls to pieces on the launchpad.

I haven't really designed a space station yet. Most of what I have ever had up there have been little more than fuel tankers. Same with bases to be honest. I lose my enthusiasm for building them after I land a couple of structures and transporters to carry them about.

[Pecan]

Oh, I just throw them together without thinking about it much ^^

Rockets:

1) Determine mission parameters.

2) Work out the deltaV requirements using a deltaV map.

3) Check Travert's mass-optimal engines.

4) Check Blizzy's engine and GaryCourt's rocket calculators.

5) Create my own engine & design choice.

6) Test and enhance 10 or 15 times.

Bases: I go for single-piece because the only way to ensure docking-ports align is by driving a rover under them and dropping legs. I might revisit bases when I install KAS, but until then they're more trouble than they're worth.

Spaceplanes: Only for SSTO at the moment and only for space-station crew-shuttle in practice. There's a very limited engine choice compared to rockets, so the rest is trying to get the wings and payload (if any) aligned with the centre-of-mass and trying to make sure the air intakes don't look ridiculous without excessive clipping.

Space Stations: Are just big rocket-components without engines. *Grin* - I tend to muck about with them. First was 'Mjolnir' (looks like a hammer), then 'High Moon' (arranged fuel tanks to look like a revolver) and most recently 'Iron Man' (anthropomorphism in space).

Whole space program: - I try to consolidate all the things I build into (sub)orbital spaceplanes, lift vehicles, space-stations, transfer tractors (to move space-station parts or to move anything else between stations), mission landers (when the stations just don't go that extra distance). Then there's all the 'other' stuff that I do in different saves that isn't about my main space program - that'll be things like challenges, tutorials, special circumstances, etc.

[MarvinKitFox]

Rockets:(When in serious mode, not in Mad Scientist! mode)

I have a stable of prebuilt rockets to use as booster, with labels like (smooth lifter, 20T to 100km) or (The Beast! 2350T to 100km, remember to throttle down during 5-12 km, use with caution!) or (HFSOAS! It Flies! 7300T to orbit, keep fire extinguisher for cpu)

erm, disregard that last one.. I think it falls under the "mad scientist" moniker.

The orbital stuff...

If it will *ever* need to dock, I spend ages on makign sure it has enough RCS. And that they are balanced. I find docking impossible without this. Otherwise, my creations come straight from scrapheap challenge.

Landers.

Wide legs. Plenty inertial stabilisers/sas. Lights to see where I am going/how high I am.

Anything beyond that is, again, from scrapheap challenge.

Space stations:

Considering what a chore I find docking to be, I make very sure what I want.

I make it look pretty, because I will see it again and again and again. Rockets/landers can be ugly, because they are use-once-throw-away. But stations, bases and first-time manned explorers are pretty, because I will see them often and/or want to make memorable pretty pictures of them.

This means a lot of scribbles on paper, plans to make it both functional and pretty, and then *many* more scribbles trying to lighten the end result so that at least my HFSOAS launcher can loft it. Yes, i've had plans too ambitious for it!

In truth, I'm still planning on my first extraplanetary base. Most complex thing I've ever built is a refuelling/science station in high Kerbin orbit, with less than 45000T of fuel on board. (yes, mad scientist strikes again, he wanted to see what speed is attainable if you throw enough thrust at it.. the answer is more-or-less 410000 m/s, via one mega-low solar flyby burn)

But above all, TAKE NOTES.

Remember what you did before, try to learn from it, and don't make the same mistakes again. Unless they are enough fun.

[Cocoon90]

There's no law that tells you really how to build a vessel, but there are a few guidelines you should follow and some rules. Efficiency is a ratio between two factors, in this case is a ratio between space travelled and fuel spent. While you proceed in the career mode, you unlock even more parts, and that make think that more is better, but it is not that simple. The best thing to do for all types of vessels are to keep things simple and efficient, and take time, don't expect to bring in orbit a 300 t probe in one shot or to fly a 100 t airship without praying the God of struts. So here's my advices:

Rockets: don't build them too heavy, do multiple modules on multiple launches. Keep things as simple as possible. For just exploring the space i usually use the lightest manned capsule, so that i can do eva and crew report with the kerbinaut. I add the minimum of science parts, i try to foresee the fuel i will spend for my destination and back, plus an extra for inconvenients.

Spaceplanes: they are maybe the most difficult thing to build because they must be stable and manoeuvrable at the same time. Some rules are that center of mass must be slightly in front of the center of lift always, even when tanks are empty. I usually don't attach anything to the wings and keep everything on the fuselage lines, exept maybe air inlets or light parts. Strut everything, especially wings and fuselage and gear bays and fuselage, so that nothig is too wobbly. Usually i use 2 types of wings: the main couple of wings evolving from the center of mass backwards, for roll control. Two other wings on the tails as horizontal stabilizers for pitch control, one vertical of nearly the same size of the previous 2 for yaw control. Canards are helpful if the aircraft won't lift even at 120 / 130 m/s on the runway. I usually place one or two engine in line with the center of mass, so that in case one of the engines flame out i still have yaw authority. This is an example of mine: XF-101C

Center of mass should be roughly in the center of the vessel , never in the back, so put fuel tanks in the front, otherwise you will flip over even if center of lift is behind the CoM.

Spaceplanes are even harder than aircrafts in my opinion, because you have to consider that that thing must travel huge distances, maybe enter an atmosphere, land, get out, travel again and get back to kerbin and land.. All of this in one ship, all that science in one vessel and all that fuel in one vessel. Just follow the rules for the aircrafts and your' re fine. In space your worst enemy, the atmosphere, is not present. Just make it simple and stabilize it with struts.

Refueling stations: there's not any rule, I just make it as big, deformed as i want, just make it in modules and launch them separately, otherwise you will struggle too much for nothing sending in orbit a rocket that with fairings looks like a mushroom because on top is too big.

Fuel lines: asparagus are the best way to launch something in orbit. I usually don't go under a TWR of 1.30 at the launchpad, otherwise i will spend more than half of my fuel under 1000 m above the launch pad.

For the aircraft building guide there is this very helpful thread by keptin.

[Jouni]

I prefer reusable modular designs that allow me to concentrate on the main payload instead of routine stuff.

Rockets: I have a medium lifter that can get 40 tonnes to LKO, and a heavy lifter for up to 60-tonne payloads. The heavy lifter is only used for fuel tankers and interplanetary spaceship thrusters. I haven't needed it much after I started using the Kethane Pack, which effectively made tankers reusable. A 15-tonne light lifter could be a good addition to the fleet, but so far I haven't come up with a good general-purpose design.

I used to try building larger lifters, but never came up with good designs. Wide rockets look silly, and the symmetry tools in the stock game don't work too well with them. There are probably some mods for that, but I haven't had the time to try them. I also don't have that much need for larger lifters, as big things can always be assembled in orbit. (Eve landers could be an exception, but so far I haven't tried to build one.) The 36-tonne jumbo fuel tank is the largest stock part, which pretty much defines how large rockets I need.

Spaceplanes: Trial and error. Avoid having too much lift, so that the balance (or the lack of it) becomes less an issue. Avoid silly air hogging designs, where the line of air flow from intake to engine is too different from the line of thrust from the engine. Place the intakes so that there is nothing if front of them. Try not to mix ram intakes with low-speed intakes, and try using only jet fuselages and cockpits between intakes and air-breathing engines.

Landers: Designed from scratch for each mission. A common design pattern is having the main payload in the core, with engines and fuel tanks around it. This usually keeps the center of mass low enough, so that the lander can land on pretty much any slope.

Interplanetary ships: I use this to push interplanetary payloads around. Getting it into orbit requires four launches, and so far I have built two of them.

Space stations: This is my station core. Standard modules include decorative ones, such as crew quarters and laboratory modules, and more utilitarian ones, such as fuel tankers, kethane refineries, and hubs with smaller docking ports. My older module designs were launched with disposable tugs, but these days I have general-purpose utility tugs hanging around at construction sites.

Bases and rovers: Never had much luck with them. The symmetry tools don't work too well with rovers, so I always get frustrated when I try to build one. Because of that, my bases are nothing more than collections of landers.

[Taki117]

Rockets- Form Follows Function, but because I play with FAR It has to be aerodynamic. More than one ring of boosters is a no-no.

Bases- I only have one, I like the way it came out, but again, form follows function. It's a kethane refinery on the Mun.

Spaceplanes- Oh, you mean lawndarts! again, because I play with FAR I have yet to master spaceplanes. I think I need larger lifting surfaces...but I don't have enough memeory for B9...

Spacestations - I've built a couple, Typically I do an "H" shape with living qurters in the middle (Two hitchhikers and some other bits) shoved between two of the multi-port things on either end for docking stuff to it. Form follows function.

Rovers/Interplanetary. Rovers are not really my thing. Mostly because I can never figure out how to transport them (And the one Apollo style rover I did manage to transport fell off the edge of a cliff) Interplanetary is easy to me, I'm currently working on an Almost Jool Grand Tour (I won't be landing on Tylo or Laythe, but I will be visiting) several of the mods I play with necessitate adding extra parts most people wouldn't have. (Satellites for RemoteTech/SCANsat/Kethane, Life support for TAC life support, Heatshields for Deadly Reentry, MOAR STRUTS courtesy of Kerbal Attachment System)

[Geschosskopf]

1. Rockets

2. Base

3. Spaceplanes

4. Space Station

5. Refueling / interplanetary

In general, the 1st step in everything is to decide on the mission objectives. Then think of how to accomplish them. This all determines what type(s) of vehicle(s)/base(s) you need and how many. Then start designing the payloads and their supporting infrastructure, if any.

1. Same as you. Design the payload, then pile rockets under it until necessary dV achieved.

2. The main purpose for building a ground base is to refuel things. Because landing just for fuel is bad economics, ground refueling bases are primarily for permanent residents, such as refueling non-SSTO airplanes on Laythe. Secondarily, they refuel ships that land there for other purposes, like rotating crew. This all being the case, you just need the minimal structure that can do the fueling. If you want to set up housing units, just land hitchhikers. All this worry about linking up base modules is unnecessary complication.

3. I don't do many spaceplanes. To be useful, they have to carry some payload to orbit and it's always a lot simpler just to use a rocket for that, especially if the payload is more than a couple of Kerbals. Now, I build a lot of airplanes that can't reach orbit by themselves, for just flying around. Sometimes there's no way to get these to other planets than to build a spaceplane ascent stage for them. But otherwise, there's very little practical need for spaceplanes. About the only practical application for them would be once Laythe gets multiple biomes. Then you could have a small spaceplane flying 1 goo and 1 bay back and forth to an orbiting mobile lab/fuel station.

4. A space station is just another form of rocket. It has a mission payload and it has to fly to where you park it, so there's really no difference. I make very few permanent space stations. Mostly, I make ephemeral stations by docking together various separate payloads to accomplish some task. Once the job's done, the parts separate and go their separate ways.

5. I am a firm believer in sending flotillas of relatively small interplanetary ships instead of trying to cram everything into 1 monster ship. All these little ships have their own transfer tugs and docking ports all over, so I hook them up into expedient stations or improvise new missions for them on the fly.

As to refueling, within the Kerbin system it's a total waste of time, energy, and money to do Kethane. It's always more efficient to just send a fuel barge up from Kerbin. At other planets, the infrastructure varies with the specific place and what you're doing. If you want to explore lots of a planet from a hub on its surface, then you need a refueling base on the planet, which just refuels stuff flying around the planet and going back to orbit. For stuff that stays in orbit, you need to get kethane from the most conveniently located low-gravity place.

For a Duna expedition, you want fuel from Ike. Ike is so close to Duna and has such low gravity that you can afford to do it very simple. Just put all the kethane drills and refinery on 1 lander that flies back and forth between Ike and ships in Duna orbit, delivering finished product. For supporting a Jool-based flotialla, which is itself supporting a Laythe expedition, you need something rather more complex. In this case, you'd be drilling on Vall. This is big and far away from Laythe so you have to be economical in the movement of the stuff. I'd recommend a big lander that does nothing but lift Kethane from Vall to orbit, where it loads the kethane into a flying tank that goes back and forth between Vall and Laythe. The drills would stay on the surface of Vall. You'd also need refineries at least at Laythe, probably also on the ground and in orbit at Laythe. At least that's how I'm doing it right now

[Dispatcher]

I've not done much in the way of docking components in orbital assembly. So far most of my missions have been launched from KSC in a single launch.

I do as the OP does for rockets. For SSTO spaceplanes, I used to use a SINGLE turbojet engine, because when a flameout occurred, the craft was not prone to lose its heading and angle. I also used to use the (insert your favorite engine here) rocket engines. Hehe! I don't want to start a "best engine" war here. Now I use some RAPIERs. Your tastes may vary. For landers, I like to make them wider than they are tall if I can. Less prone to tipping over on a steep incline.

I have never built a space station, refueling depot or base. Sounds fun though. Good luck!

[Tank Buddy]

Somehow I just have a gut feeling if something will work, so I don't really need any planning. I just go along with what I think will work. And it does most of the time, probably because I haven't tried anything crazy yet.