Do a different rocket for each payload?

[PDCWolf]

I make the payload and then I see if it fits on a current rocket, otherwise it's time for a new one. Voted no.

[Polstar]

I have 4 launch vehicles I use, the main work horse has a main core with 2 boosters identical to the main. It looks very much Delta IV Heavy although I'd not seen the Delta IV until after I designed it!

I do customise the upper stage sometimes but that depends.

[TerLoki]

I have three different launchers right now: A 2 stage medium lifter, a 2 stage + 2 boosters heavy lifter, and the heavy lifter modified for 3+ meter payloads. So far that's pretty much all I've needed, though I do use specially made launchers for really small payloads that don't need to go all that far.

[merendel]

I tend to standardize my boosters. Usualy after the first few key nodes in a career run you can build a fairly nice launcher able to lift a 20ton or so payload. Even once you've got better parts theres really no pressing reason to redesign the smaller lifter to incorperate them so may as well keep that launch system for the light stuff. Progressively heavier loads require bigger parts unlocked from higher tier techs but agian by the time you need them you have the tech to make them. Once designed new tech does not always invalidate it for its payload limit so no redesign is needed. The only exception to this is radical mod tech comeing into play such as KSPI with beamed power plasma launch systems trouncing standard chemecal rockets.

I tend to end up with launch systems for 20t or less payloads, 50ton payloads, and systems steping up in 50 ton increments. The first 2-3 tend to be fairly low tech requirements while the higher payload launchers tend to be up in the skipper/mainsail tech range. I do include deorbit options for the final stage of the boosters in the case of it ariving in a stable orbit instead of suborbital. Generaly this is not a huge deal however.

[Madrias]

Rockets? How primitive.

Granted, I'm guilty of making new spaceplane designs depending on what I'm dumping in space. Still got a couple of 'winged satellites' floating around Kerbin...

[Vonar]

I build payloads based on what my rockets can deliver to a Low Kerban parking Orbit. No sense in wasting delta-v to go any higher when you've got a armada of space tugs

[IrRedemption]

I build a rocket that has enough thrust to carry what i need to orbit efficiently and will attach any other parts if i need to go someplace far away.

[DocMoriarty]

I usually design all payloads, intermediate stages and launch rockets as subassemblies and combine them as needed for the mission at hand. Here a screenshot of my rocket subassemblies.

[Pthigrivi]

I have 3 lifter subassemblies, but now that Im building off-world bases almost always use the biggest one. I know airhogging feels like cheating but when you can deadlift almost 70 tons with less than 1000 in liquid fuel who can resist?

[nerdboy64]

Currently, I typically build a "new" lifter every time, though I generally use the same design repeatedly. However. with the addition of subassemblies and my recent experiments with heavy-lifting SSTO concepts, that may change in the near future.

[MaverickSawyer]

I tend to do a custom booster for each payload, but I've gotten so good at eyeballing it, I spend more time on the payload than I do on the booster!

However, I will often design the payload for multiple missions... For example, the lander for the Munar and Minmus missions are identical... If it works on the Mun, it most certainly works on Minmus.

That said, certain elements do reappear repeatedly... Common heritage between designs provides me with the reassurance that it will complete the mission without issue. (it also simplifies the design phase. )

[Spatzimaus]

Once upon a time, I used to make a new booster design for each payload, but that got old very quickly. Once we got subassemblies, I switched to a set of standard boosters that I now use for nearly everything I launch. For Kerbin orbit launches, all of my designs are SSTO rockets with a delta-V of about 5600m/s, using 3.75m parts from KW Rocketry.

Here's the largest, the Brick-41:

The name is in reference to how it's 41 linked rocket stacks. The stacks are held together using struts and wing parts, with no fuel lines or radial separators, and are controlled by a probe core mounted just below the main connector at the top. Nearly the entirety of what's pictured there is the lifter; the payload, in that screenshot, is a tiny 1.3-ton ion probe mounted in the middle. It's a 12000-ton lifter, with the ability to get a payload of about 900 tons into low Kerbin orbit, detach, and then safely de-orbit itself. It's exactly 800 parts, too, so the frame rate isn't too terrible. Since it's an SSTO, there's no complex launch profile needed; just slowly throttle down as its weight decreases, until you hit about 15000m and can throttle back up again.

The initial use of the -41 was to lift my 870-ton space station in a single trip. That's the reason for its shape; the flat top means I can mount awkward payloads (like a station) on top and have plenty of places to connect lateral struts for stability. I've used this basic idea for lots of other payloads, like rovers and such.

As I said, that's my largest, although I've toyed with a 49-stack version for even bigger payloads. (Any more than that and I can't fit it in the VAB.) My smaller boosters use the same concept, just with fewer rocket stacks. The smallest, the Brick-1, is just a single stack that can handle payloads up to about 25 tons. Then there's the Brick-9 (the 3x3 block in the middle), -21 (add four triangles around the sides), and -29, each with progressively larger lift capability. The -21, for instance, can handle anything up to ~450 tons (meaning pretty much anything I want to lift), and its part count is only around 400, so I've used it for lots of things.

The only time I make anything more complex is when I'm making a mission designed to go to the outer planets (or Moho), and even there I've found I'm better off just stacking an extra stage on top of a larger Brick. A 900-ton capacity on that largest booster means I can get some pretty huge transfer stages into orbit...

[leops1984]

I have a standard lifter for each size I use. (1.25m, 2.5m, and 3.75m). All lifters are designed to the same basic principle: four liquid booster cores around a fifth core, all of the same design (like the CBC used in the Delta IV). All five cores are crossfed with asparagus staging. The four booster cores may also have one solid booster strapped to each of them.

To build my rocket, I build each payload independently, move it over as a subassembly, and use SelectRoot to select an appropriate root part (to prevent certain 0.23 bugs from manifesting).

[Jouni]

In my main sandbox game, I have standard lifters for roughly 5 tonnes, 15 tonnes, 40 tonnes, and 60 tonnes. I haven't used them that much recently, because I already have pretty much everything I need in space.

[wasmic]

I have a rocket subassembly sytem that I call Cosmos. The biggest rocket I made with that system is capable of putting 48 tons on a trans-Duna injection. With FAR, it's capable of even more. My most powerful rocket ever, though, was done completely without asparagus and can put about 75 tons (haven't tested, possibly up to 100 tons) into orbit. I don't use tugs as I don't like burns with less than 0.5 TWR. For small payloads, I frequently make custom launch vehicles, as I find it to be a good source of fun.

[pauix]

If something worked once, it will probably work twice unless the payload is heavier, in which case I either slap some SRBs into the lifter or I add another engine ring before giving up and designing a new one.

[SSSPutnik]

It depends... I have a few launchers I tend to use, otherwise I will build one if it's suitable.

I have been known to use a 320t to LKO launcher to send 60 ton craft up though...

[magnemoe]

Tend to use new rockets for each payload, either the cargo is light and its trivial to make the rocket or the payload is large and I need to build the rocket around the cargo.

[Frank_G]

I have a set of launch stages, sorted by lift-capacity. After selecting the one i want, i only adjust fuel levels to launch most efficient. However i love to redesign stuff and upgrade my presets with more efficient ones from time to time. I play KSP for four months now and i bet there will be lots of optimization runs as my skills and the game content improves. What a great game.

[sgt_flyer]

For most of my payloads with weights under 60tons, i have a series of subassemblies based on angara, which allows me to assemble a suitable launcher in a few clicks, for a large range of payloads.

[MKI]

I have 4 launch systems with multiple varients

The first 3 have Mainsale Liquid fuel boosters without asparagus (its ugly) that feed into the core stage

The first two launch designs have the same core, 4 t30s, and 4-t45s

The first primary design has around a 60T Payload limit for lower kerbin orbit.(Majority of missions fit this launcher)

The secondary is a longer distance design with around a 50T Payload limit, with the shorter core stage and a second stage with LV-Ns to complete orbit and is my primary space tug design.

The third is an older design with 5 Mainsales, leading into 5 Skippers that feed into the core skipper with multiple SRB's, this design has carried a 100T object into space, but i haven't tested more or really used it as i tend to keep launchs smaller to keep lag down.

The final design is a small sized 4 t45s , with 4 t30 liquid fuel boosters with a single LV-N upper stage. Generally used for small probe missions.

The only time something gets a special launcher is if it is unstable with the current designs, which i tend to modify structurally to keep things from topping over, but this happens rarely as i said i keep missions small and tend to dock many parts together to get a larger project done.

[DunaRocketeer]

I have 3 (eventually 4) basic launcher designs. I think that keeps things more realistic.

I use subassemblies, but the designs usually slowly evolve as I work through the tech tree. The one lifter that has stayed virtually the same throughout is my light lifter which was a kind of Saturn 1b style solution to the problem that at the time, I didn't have long 2.5m tanks unlocked, so I clustered 1.25m parts for the first stage. I works well and looks good, so I'm keeping it as is. I like the idea of having an old workhorse that has served the program from almost back to the beginning.

No asparagus, and nothing beyond Delta IV Heavy designs in terms of common core boosters.

Edited March 19, 2014 by DunaRocketeer

[Seret]

I voted yes, but I have used standardised rockets before. Generally however I just find it easier to build the payload, then slap enough rocket parts underneath it for the ÃŽâ€v to hit my target. I tend to be a bit minimalist, I don't like adding any more parts than I strictly need.

Having said that I do find myself applying tried-and-tested combinations of parts a lot, even if they aren't exactly the same launcher.

[Red Iron Crown]

Standardized booster subassemblies for most rockets here, too. I only do a custom booster if the payload doesn't fit well on one of my existing ones.

[possum]

I try to use the same booster but sometimes that just is not practical.