It's just role-playing fluff for now, but when the full game comes out, they mentioned you'll be able to recover and reuse parts if they have their own 'chutes, so I decided to try it with this design. I built a Kerbatta Trio this morning off the same basic plan, but omitted the anemic three-SRB second stage. The 'orbiter' section (chute, capsule, decoupler, fuel, fuel, engine) still makes it EASILY into orbit with one whole tank left.