I have an idea for a solution that's simple. Some experiments can't be transmitted at least right away, while others can. A mass spectrometer and science lab would be late-game unlockable parts to analyse EVA samples, which would have to be returned under most circumstances. A new kind of experiment would be added that always has to be returned. Maybe something involving biology. This would motivate the construction of bases and stations on interplanetary missions. Jeb goes and collects some Duna rocks and takes them back to the lander where Bill pops them into the "Insta-Study Elemental Content Analyzomatic". Meanwhile in the Hitchhiker some bean sprouts and a cage of hamsters are gleefully running in their wheels in low gravity on Duna. Bob must make sure they survive the trip to Kerbin because other KETA won't allow the results to be published and no science points will be granted.
