A story behind the birth of the shuttle.

When we're years before the every day use of a new system, it's very hard to think what the consequences of a failure could be.
What the consequences of attaching the shuttle alongside its boosters are.
It's all very nice to have just 4 working shuttles, but if one fails, there are only 3 left and so many fewer missions for the system.
Also, if one fails, 7 lives can be taken away very suddenly.
That's what comes with re-usability.

Non re-usable or partly re-usable small spacecrafts, meant to stay a long time in space, riding on top of the rocket, will have a different approach.

Even if one fails, other spacecrafts are ready , waiting in the factory.
As they're smaller, a correction could be achieved much faster.

Raoul