Sci-fi setting where cargo is being shipped to colony worlds. If a spaceship has to land and take off again, that costs a lot of money, so that mode of transport is reserved for people and urgent, high-value cargo; the plan is to get bulk cargo the last lousy few hundred kilometers in drop capsules, which aerobrake, parachute, splash into the ocean and get towed to shore by boat.
The maximum speed at which a capsule will hit atmosphere is 5 kilometers per second. (This is very hypersonic, but still slower than standard orbital velocity.) Their size will be on the order of a few meters, and they will be made of ordinary materials like steel and composites.
What shape should the capsules be?
Aerodynamic considerations suggest they should be round, perhaps ideally the quasi-teardrop shape (lens with short trailing cone) of the early space capsules.
On the other hand, that's a terrible shape for efficient packing aboard a freighter. Efficient packing would much prefer rectangular boxes like today's cargo containers. But sharp corners would probably melt when the capsule hits atmosphere.
Would it be viable to at least compromise on something like a cylinder shape?