Standard part sizes for different stages/craft

[kmyn]

As a relatively new player, as I'm progressing on my career game I am starting to unlock the larger (and smaller) size parts and I am curious to know what the 'standard' sizes are that most people use for the various stages of their rockets.

Is a launcher generally 3.75m, second stage 2.5m etc with probes/landers being the smallest size? I'm sure there's no set in stone rules but I was wondering what the most used sizes are for various things? Or is it completely mission-dependant and there's no general consensus at all?

[Taki117]

Generally speaking a stage is only as large as it needs to be. Just sending a 1 man capsule to orbit? Use a 1.25m stack. Sending a 3 man capsule to that awesome space station of yours? 2.5m Stack, but short. Full on apollo mission with an accurate recreation of the Lunar Lander with structural panels and panel fairings? Better break out the big guns and use 3.75m parts.

Worry less about part size and more about dV, form follows function with rockets.

[Pecan]

In general only use the larger parts to reduce part-count. 2.5m is useful for large vehicles assembled in orbit, by docking, because the large 'senior' docking port causes less wobble than the smaller ones. Otherwise the trick, as Taki117 said, is 'only as large as it needs to be'.

Design small and, especially, light. Less is more and all that stuff. Work backwards from the end of the mission as in Long Tom - Section 3, Chapter 5 of the 'Exploring' tutorial in my signature.

Edited February 26, 2015 by Pecan

[eddiew]

Don't worry too much about pushing for large diameter - no use having a 3.75m tank if your only reaction wheel fits 1.25. You can do a Munshot with 1.25m tech, 2.5 is only required if you have a 2 or 3 man pod, and 3.75 is unnecessary. Rockets in KSP can be pencils; exactly as wide at the top as they are at the bottom. Though you'll probably want to strap solid fuel boosters on the aft-end ^^

The tech tree is a little clumpy, but you don't go too wrong if you unlock it in vertical stripes, rather than trying to race down one branch or another.

As others have said above; minimise, minimise, minimise - the three keys to profiting in your career game!