Machinist never stopped working even after advanced CNCs proliferated. Humans had records of how things were made and yet new generations had to relearn it - and fail in the process.

This mission is not about sending stuff out to deep space. Its about sending out new generation of humans to deep space.

Even if you could guarantee that these new humans have exact same experience of past humans, can we guarantee that past decades simulations or theoretical knowledge acquired - while NOT actually doing something - will effectively reduce the chances of mortality?