Sounding rockets or suborbital launches basically go straight up and then fall down without entering orbit. That requires much less fuel mass than to achieve 8,000 m/s or so orbital velocity.
- For how long could such a launch put a payload in freefall microgravity (which could be of interest to science, manufacturing, tourism)? I suppose that there won't be much microgravity once atmospheric braking sets in below 100 km altitude or so.
- How would today's most powerful launcher, Delta IV Heavy, perform as a sounding rocket in terms of altitude and payload time in freefall? Or a Saturn V? The EFT-1 with Orion on a DIVH lasted for over 4 hours, but was actually designed to accelerate the payload down through Earth's atmosphere.