Instead of launching a payload to orbit, consider one of the big launchers of today (like Atlas V, Ariane 5, Falcon 9, Proton) being used as a sounding rocket for astronomical observation purposes. Lifting its payload thousands of kilometers into space and then falling down to Earth within an hour or a few.
Compared to an orbital insertion, a sounding rocket mission would allow for much more payload mass since no acceleration to orbital velocity is needed.
It would be easier for a reusable first stage to land.
The design of the payload could be much simplified: A battery as power supply. No need for on board propulsion. No communication needed, the data collected could be landed as a physical memory chip. No radiation hardening needed for such a short exposure so the cheapest and latest off-the-shelf electronics could be used.
Sounding rockets do contribute alot to science already, so I wonder how it might be expanded to big sounding payloads. The payloads could either be discarded after their one and only use (as in making one observation of e.g. an exoplanet when it is known to transit), or be soft landed and upgraded and reconfigured for another mission.
Why aren't sounding rockets made as large as orbital launchers? Are there show stoppers here? For example that orbital launchers are ill suited for sounding missions. Or that there aren't as many simplifications to be made on the payload as I suggest here. Or that the science opportunities don't motivate say $100,000,000 for one or two hours of observation above the atmosphere.