Yes I agree. Up to around two years in space, you can use the same methods as used for the ISS, somewhat improved. That’s the aim of NASA in the near future. An international outpost near the Moon gets closer to reality

But for missions of more than two years, then it starts to become very inefficient to use those same methods. We need to start using much better recycling, and the easiest is to use biological closed systems as you say.

• Biological closed systems research in LEO
• Sending humans to Mars for flyby or orbital missions - comparison of biologically closed systems with ISS type mechanical recycling (also relevant to long duration lunar missions)

I also agree on the importance of doing research into artificial gravity. Although the early experiments in space were promising - humans much less affected by spinning motions in zero g than they are on Earth (possibly because the ostoliths which experience gravity as a linear acceleration along the spin axis on Earth are not stimulated in space), and rats in a centrifuge far healthier than rats that are not centrifuged - there haven’t been any follow up experiments at all.

• Joe Carroll's tether experiments in artificial gravity - which we could do right now
• Small centrifuge based artificial gravity experiments in LEO