Personally I'd break science up into multiple parts.
Flight - For parts like wings, air breathing engines, fuel tanks, landing gear, etc. You gain flight science by spending time flying in an atmosphere. Keeping with how Kerbal does things you'd get your first flight parts (control fins) with mostly science gained while doing rocket launches however after those first fins and maybe basic plane capsule you need to build actual planes. Rocket planes at first obviously. You'd get huge science bonuses for managing flights at Eve, Duna, Jool, and Laythe.
Rocketry - Science gained from actual rocket launches. Nothing really radical here. Launch rockets, any kind of rocket.
Landing/Rovers - Recover those rockets or at least leave them stranded, intact, on other bodies. Get better parachutes, landing struts, ladders, wheels, etc.
Probes - Get better probes by launching unmanned rockets.
Crew - Get better bits for your crew by launching more kerbals into space. Keep them there (space stations, planetary bases) for big science bonuses and rapid unlocks.
Utility/Science - Want to do more science? Keep doing experiments to unlock more experiments and better utility devices like bigger batteries and solar panels.
So that trip to Pol would have given me lots of Rocketry, Probe, and Utility science points. TO buy more parts for that kind of mission.