The ISS has taught us a lot that we didn’t need to know. OK, so now we know more about the various bodily maladies that prolonged zero G can cause. But the ISS hasn’t taught us anything about how to prevent those maladies, because we already know the answer to that one: Don’t expose bodies to prolonged zero G. If we want to send humans on a multi-year mission to Mars, there’s no reason not to give them gravity in the process.
Now, there is an open question of just how much gravity is needed. The longest any test subject (human or otherwise) has ever been exposed to nonzero gravity less than the Earth’s is the paltry few days the Apollo astronauts spent on the Moon. It would be nice to know if our Mars explorers could get by with 1/3 g, or 1/6, or 1/10, for the duration of their mission, since that would enable a cheaper artificial gravity setup. But that’s not something the ISS can test.
All that said, though, if we’re going to waste large sums of money for the sake of national prestige, I’d far prefer wasting it on the ISS to building another aircraft carrier.
All true, except that the cost of the ISS (which is more than six times the original estimate) is sufficient to build ten next generation Ford class supercarriers.
On the other hand, for the cost of the ISS, we could have launched nearly fifty interplanetary ‘flagship’ missions equivalent in mission capability to Cassini-Huygens, or ten missions of the cancelled/rejected Jupiter Icy Moons Orbiter and Neptune Orbiter, with enough left over to develop a solar-orbiting deep space telemetry and navigation infrastructure and hazardous object watch, not even accounting for economies of scale of building multiple missions around a common spacecraft bus, which would have provided extensive detail on those systems that we won’t be able to get for another generation at minimum. We also could have spent that money developing the technology and infrastructure to support a more reliable and lower cost access to space capability rather than continuing to support the Space Transportation System (‘Shuttle’) with all of its limitations and design deficiencies.
