It might be nice if ED could take some inspiration for sciencey stuff from KSP.
It probably couldn't work in quite the same way but it might be nice if, for example, you could start off by selling some exploration data at a specific station and that'd spawn a chained mission, requiring you to go and scan specific systems/planets.
Do that and you'd gain access to basic scientific modules which'd allow you to carry out more complex (and rewarding) missions.
Complete those and you get even more cool toys to play with.
Ideally, perhaps the best way to ensure this sort of thing is repeatable, rather than being a once-only "unlock", would be to do it via "payloads"?
At a certain point in your scientific career you'd gain access to a selection of "Payload Bays" and, after installing one, you'd have the opportunity to be take on specific missions which made use of it.
"Take this orbital telescope to X system, locate a water world and deploy the telescope in orbit and then protect it for 30 minutes while it completes it's study of the planet surface. Afterwards, recover the telescope and return it to us"
"Our scientists want to study neutron stars. Take this instrument package and fly through the cones of 10 neutron stars and then return the data to us"
Etc.