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I'm not sure what the point of cramming 54 people into the cross-sectional area is as a demonstration. After all, if you give each person one square meter, you

by jp57 2y ago

I'm not sure what the point of cramming 54 people into the cross-sectional area is as a demonstration. After all, if you give each person one square meter, you could fit the entire population of the earth into the state of Connecticut. (with some room left over) 54 people in the module volume even seems like it would be quite cramped and unpleasant for anything more than a short trip. Also, is enclosed volume really the thing that needs to be optimized? Presumably the ISS has so much less enclosed volume for its size because its mission demands more external surface area and/or other things like modularity that are at odds with maximizing enclosed volume.

itishappy 2y ago
I think the driving force for the shape of the ISS is actually the available launch vehicles. Skylab was a lot closer to the size of this thing than the ISS is because it went up on the last Saturn V. I walked through the Skylab replica at Space Center Houston just last week and was blown away by the scale. https://www.youtube.com/watch?v=d1sr6aVzW9M https://www.youtube.com/watch?v=d1sr6aVzW9M
ben_w 2y ago
Sure; they say it's "roughly half" the "usable volume" of the ISS. The latter being 388 or 900 or 1005 m^3 because habitable != pressurised, and for the latter NASA publishes two values[0][1], so that's about 194/450/502 m^3 total or 54 people 3.5/8.3/18.6 m^3 per person. For comparison, the Apollo CSM and lander were 6.2 m^3 and 6.7 m^3 total for 3/2 crew, so even at that (I agree unpleasant) density, it's a plausible size for the pressurised volume of an emergency-return-to-earth lifeboat. [0] "Habitable Volume: 13,696 cubic feet (388 cubic meters) not including visiting vehicles" "Pressurized Volume: 35,491 cubic feet (1,005 cubic meters)" - https://www.nasa.gov/international-space-station/space-station-facts-and-figures/#:~:text=1,005 https://www.nasa.gov/international-space-station/space-stati... cubic meters [1] https://www.nasa.gov/reference/international-space-station/#:~:text=The%20ISS%20is%20the%20largest,400%2C000%20kg%20(900%2C000%20lbs) https://www.nasa.gov/reference/international-space-station/#...

by jp57 2y ago

itishappy 2y ago

I think the driving force for the shape of the ISS is actually the available launch vehicles. Skylab was a lot closer to the size of this thing than the ISS is because it went up on the last Saturn V. I walked through the Skylab replica at Space Center Houston just last week and was blown away by the scale. https://www.youtube.com/watch?v=d1sr6aVzW9M https://www.youtube.com/watch?v=d1sr6aVzW9M

ben_w 2y ago

Sure; they say it's "roughly half" the "usable volume" of the ISS. The latter being 388 or 900 or 1005 m^3 because habitable != pressurised, and for the latter NASA publishes two values[0][1], so that's about 194/450/502 m^3 total or 54 people 3.5/8.3/18.6 m^3 per person. For comparison, the Apollo CSM and lander were 6.2 m^3 and 6.7 m^3 total for 3/2 crew, so even at that (I agree unpleasant) density, it's a plausible size for the pressurised volume of an emergency-return-to-earth lifeboat. [0] "Habitable Volume: 13,696 cubic feet (388 cubic meters) not including visiting vehicles" "Pressurized Volume: 35,491 cubic feet (1,005 cubic meters)" - https://www.nasa.gov/international-space-station/space-station-facts-and-figures/#:~:text=1,005 https://www.nasa.gov/international-space-station/space-stati... cubic meters [1] https://www.nasa.gov/reference/international-space-station/#:~:text=The%20ISS%20is%20the%20largest,400%2C000%20kg%20(900%2C000%20lbs) https://www.nasa.gov/reference/international-space-station/#...