It's about more than just shutting down though. Biological complexity makes it infeasible to significantly engineer our biological bodies to e.g. make them smaller to reduce fuel costs, or make backups so that we can easily do potentially dangerous experiments involving ourselves (also reproducible experiments).
My prediction: humans will have to be 100% human technology to free ourselves from the Earth.
My prediction: humans will have to be 100% human technology to free ourselves from the Earth.