I completely agree that at this point there is much less to 'explore' in LEO than in the past. However there's a huge difference between spending 10 days in or

I completely agree that at this point there is much less to 'explore' in LEO than in the past. However there's a huge difference between spending 10 days in orbit in the shuttle and dozens of man-years in zero-g with high radiation and in an isolated environment. Several of the goals for the ISS (at least from NASA's perspective) were based on getting experience operating in space for extended periods of time, for human health, for construction and engineering, and for operations over inter-planetary length periods. Experience and knowledge on all those fronts is needed to progress to further out, more isolated manned missions. It's also not quite true in sentiment to say that humans survive in zero-g the same way they did in 1969. None of the early space missions spent that much time in zero-g, and we continue to learn a lot even after MIR and Skylab about the lack of gravity and radiation on human health. Even now there is new research coming out of the Apollo-era missions related to human health. [1] A similar situation exists exploring the depths of the ocean. You don't build a submersible to go 7km down until you've got a good grasp of operating at 300m. Likewise it's still quite valuable to explore at 300m since there's a lot we don't know (far more than LEO) even though we've been to 7km. Putting humans into space at all is hugely difficult and expensive. There were a lot of arguments in the scientific community against a manned mission to the moon. And it's completely fair to consider the ROI and dollar/manpower value spent on manned space (and the ISS in particular.) I personally think there is huge value to manned space exploration beyond first-order economics, and from that perspective I think the ISS has and continues to accomplish much more than just random science projects. Especially given the political constraints it operates under. [1] https://news.fsu.edu/news/science-technology/2016/07/28/apollo-astronauts-experiencing-higher-rates-cardiovascular-related-deaths/ https://news.fsu.edu/news/science-technology/2016/07/28/apol...