Do a different rocket for each payload?

[palioxis1248]

I've been using the same super heavy launch vehicle for everything from tiny ion probes to bases.

[NecroBones]

The main thing that kept me from using the saved subassemblies is that it would screw up my struts. With 100+ struts (necessary with stock KSP physics with large lifters, IMHO), going around and re-doing them was more painful than taking an entire saved ship, and just rebuilding the payload section. With Kerbal Joint Reinforcement though, I may rethink this. The strutting requirements aren't so ridiculous.

[Umlüx]

i have several launchers saved as subassembly. ranging from 5 to 80 tons, plus a 200tons monstrosity for a little extra kick

most of them are built after real rockets. i have a ariane5, falcon and a delta heavy lookalike.

[Seret]

100+ struts (necessary with stock KSP physics with large lifters, IMHO)

That's a lot of struts.

[nimbim]

I build the mothership core and/or lander for each mission and then send a collection of pre-made parts to dock in LKO.

[Caelib]

I try to keep my skills "fresh" by building the minimum amount of rocket/lift necessary based on the payload -- I'm sure this will help greatly when Contracts/Currency is released

[NecroBones]

That's a lot of struts.

Yes, it is. They add up really quickly when you're stitching engines to tanks, tanks to other tanks, adding diagonal and cross-brace struts to strengthen the center of the ship and keep it from breaking between the lifter and upper stages, and brace the payload to minimize wobble. After adding KJR, I went back to one of my existing designs and pulled off as many struts as I could, and still get a successful launch, and I pulled off something like 160 struts. It was nuts.

[Seret]

I don't think I've ever added more than about 20 struts to a launcher. Generally three per booster, and maybe 3-6 for wobbly payloads. I don't build really massive stuff though, biggest rocket I recall launching would have been six or seven orange tanks.

[NecroBones]

Yeah, this was one of my largest builds in that case.

[SkyRender]

I'm one of those weird old-timers who got into the game before subassemblies were a thing, so I tend to build out the lifter stage every time even when it's effectively identical to other lifter stages I've built. It just... doesn't take me very long, so I never really feel compelled to make a prefab for it. Certainly I never feel the need to use subassemblies for Career mode; every mission I do sends my Kerbals so far ahead on the tech tree that it makes previous builds look prosaic by comparison.

[Pthigrivi]

Hey who wants to see my uberlifter? I thought so!

18 turbojets, 4 Nuclear Rockets, (crazy airhogging abuse )

The lifter's turbojet nacelles carry 9600 in liquid fuel, and the tug carries 2000 in LF/O. Both the nacelles and the tug are fitted with parachutes for safe re-entry and reuse.

Spinning up the turbojets before releasing the clamps,

I power up to 10k and start a slow turn that ends at about 5 degrees as I approach 30k. The innermost turbojets flameout at 32k, generally by then we're at about 1750 m/s.

The rest of the turbojets continue to draw from the intakes while the 6 way symmetry keeps things stable, and by the time we ditch the nacelles at about 40k we're over 2100 m/s.

The nuclear rockets get us from there to LKO. Thats 2 full orange tanks in one lift with enough to spare in the tug for rendezvous!

Im sure these shenanigans will end when they clean up the aerodynamics. Until then I'll just pretend they're scramjets.

Edited March 19, 2014 by Pthigrivi

[MedwedianPresident]

I usually use subassemblies.

[Tidus Klein]

I always make over engineered lifters that I just toss in the sub-Assembly file I have 4 right now.

one for small satellites, one for station modules, one really out of date one that should be tossed in KSPs dumpster, and then one super massive 570 part crazy lifter I use for all-most all my interplanetary missions, lets just say It has enough oomff! to put the last stage (stage 1 of 3 for the lifter) with pay load in an elloo intersect. yaaaa its OP in fact I may still have the album...

EDIT! found it!

Javascript is disabled. View full album

OOO AND PS asparagus needs to stay on the plate not on rockets I would hate to see how far this thing would go if it was introduced to asparagus....UUU gives me chills just thinking about it. escape velocity any one

Edited March 19, 2014 by Tidus Klein

[Brapness]

Personally I find myself becoming sentimental about old designs in career mode. Presently I have two main lifters, a big one I call Obelisk that I built before I got fuel lines and an asparagus design that uses LV-T30s and a skipper engine (as I haven't unlocked the mainsail yet) named Skippergus. Although Skippergus can lift a heavier payload higher, I just really like Obelisk for some reason.

Seeing as of yet in career mode I haven't launched anything particularly heavy these two do just fine. Obelisk is fine for LKO station modules and Skippergus does 1-way trips to the Mun landing base parts and rovers. I use a slightly modified version (more delta-v but slightly more prone to accidents) for landers I expect to return. Both can launch ships on return missions from Minmus and both have sent probes to other planets. I also have a simple liquid fuelled tri-stack for launching small payloads.

[Pecan]

I spent a lot of time designing and building launch vehicles when I started with KSP so I have 30-odd pretty-heavily optimised standard lifters from 1t - 80t with ~18% payload ratio. I've never thought they were good enough to publish though; firstly because I haven't tried (enough) using jet first-stages and secondly because, well, they are mostly pig-ugly and still not as efficient as some that are available (temstar's originals for a start). That means I tend to use engine and rocket calculators a lot (ie; blizzy's, et al) and re-visit/build/design for all but the most trivial launches. When I need to just throw something into orbit to test the later stages I'll pick my best standard launch vehicle for it the, after making sure the payload is as it should be, (re)build a specific one for it.

Asparagus is almost a must - but so is a limit of 2 'rings' (usually one 1 and often only 2 or 4 side-stages, rather than a full ring) and nosecones/aerodynamic fairings. Unless designing purely for efficiency (as above) my ships look good too. All my ships use the most efficient engines possible (travert's mass-optimal charts) - so Mainsails are right out - and none use part-clipping (which limits my engine clusters to 7 in most cases).

Edited March 19, 2014 by Pecan

[Brainlord Mesomorph]

I have a standard 50-Ton lifter for most payloads. (i try to keep a lander and fuel under 50 tons)

If its much heavier or lighter then "yes."

[rkman]

yes.

I enjoy the design process, and there is no cost saving in using existing designs (hint, hint).

[paul23]

I see doing this as my main goal. Making the most cost efficient rocket. Often i make a booster stage that falls off around 8-10km, then a proto-orbit stage (appogee at around 100km, perigee around 60km). I then decouple the second stage - which should be completelly empty of fuel and uses only drag to fall down & is then reusable). And finally the stage(s) to get where I want to go.

But all in all: I wish to minimize the take off mass, and make sure I have no left over fuel. If more than 5% of my fuel at any stage is left over I will revert the flight and do it again.

[Engineer of Stuff]

I have one giant rocket that I use for everything (750+ parts). It can go past Duna. It is very inefficient to use a giant rocket just to get a single satellite in orbit, but it gets it to orbit fast.

I don't use pre-made ships in career mode.

Edited October 28, 2014 by Engineer Of Stuff

[Wanderfound]

Pretty much the only time I fly rockets from KSC these days is when I want to lift station segments that are too large for a cargo bay. I'll usually build the lifter from scratch when I do that, but I've done it enough that it's more a case of assembly than design.

Big central core, onion-staged liquid boosters placed with 4x symmetry, some Sepratrons at the top of the boosters, maybe a few SRBs strapped on the outside if the initial TWR is inadequate. If I had to, I could probably slap one together in about thirty seconds.

Lately I've been doing the single-design thing a bit with spaceplanes, too. Once you've got a good basic airframe worked out, it's very tempting to just tweak and stretch it into assorted close variations rather than design from scratch each time. Want to deploy a rover? Just flip the cargo bay upside down. Need a heavy lifter? Double the size of the cargo bay and add another pair of turbojets. Need a tanker? Swap the cargo bay for more fuel and extend the engine nacelles. Need a long range specialist? Change the Aerospike to an LV-N. Etc.

[xrayfishx]

Designing a launch vehicle for each payload is time consuming in RSS. I try to be efficient and designing an efficient launch vehicle takes time. Also, there are often weird problems with mods so when a design works well and doesn't glitch too much, it's a huge success for me. If a design flies well and it's easy to follow an efficient ascent path with it, it's again a huge success. Huge successes don't happen often and most of my designs end up scrapped so clearly it would be a bad idea to design a new launch vehicle for each payload.

[Pecan]

I am amused that mine was the last post before this thread was resurrected and how much my views have since changed. At the time large ARM parts, cost and recovery didn't exist so the big change is that I rarely use asparagus any more. Furthermore I have since worked out a more-or-less consistent set of vehicles that I use and hardly ever need to design a new launch vehicle. Like many people, I have moved towards spaceplanes and SSTO rockets/VTVL vehicles as I've had more time from designing launch rockets.

[Feldynn]

I tend to modify existing launch platforms to fit whatever payload I'm sending. As an example in my current new 0.25 career game I have a fairly cheap rocket / lander that will make it to Mun and back without leaving any space junk, when it came time to deploy comms satellites for RemoteTech I used the same complete rocket but with some minor alterations (i.e. shoved some satellites on it) and it worked perfectly.

Of course I've yet to venture out beyond Kerbin's SOI, though I don't see myself doing anything much different. Same basic principle of getting a vessel designed / built to go out to whatever planet then refine it as necessary for payloads .

[hellion13]

I always used an Apollo style approach. Even if it ment cloning the main core, which was Mün capable on its own, into multi-core asparagus monsters that scored a 0 for efficiency.

[Jouni]

While I find rocket design fun, designing similar rockets quickly gets boring. I try to reuse existing rockets to some degree, but they often become obsolete, as I install new mods.

Right now I'm playing with FAR, DRE, and 6.4x Kerbol System, which provide a nice balance between realism and casual gameplay. I have two stored subassemblies for launching larger payloads.

The Big Rocket weights a bit over 2000 tonnes and lifts around 100 tonnes to LKO.

The Medium Rocket is based on the same design, but with less boosters, a smaller upper stage, and a smaller lower stage. It weights around 1100 tonnes and lifts around 50 tonnes.

I also have a tiny rocket for payloads less than 2 tonnes, but so far I've used it only for launching the debris cleanup vehicle.