Modular Ships

[Suicide Junkie]

Sure, just design a hull for one of the roles, then copy it, and replace just the mission-specific components.

When you retrofit between 'em it'll take only one or two turns to finish. Just keep the changes low.

Alternatively, you can take a large transport and put two or three of each type of bay, then add lots of cargo storage. It'll be able to launch whatever you put in, and if you need to launch quickly, you can transfer the cargo to a nearby planet or specialized launch vehicle.