3 ms·

Well, Mars has 1/3 of earth gravity so that helps. So for spinning the capsule, you only need say 1/5 earth gravity to be reasonably capable of walking on Mars

by vitiral 2mo ago

Well, Mars has 1/3 of earth gravity so that helps. So for spinning the capsule, you only need say 1/5 earth gravity to be reasonably capable of walking on Mars. Does that help?

m4rtink 2mo ago
You can't really spin a small spacecraft to get rotation gravity - the rotation period would make it unworkable. However, you can connect two parts of your space craft with long cables and then spin the resulting contraption around its now center of rotation & the rotation period will be manageable. This concept has been nicely demonstrated & quite well popularized by the recent Project Hail Mary movie.
- triceratops 2mo ago
  > This concept has been nicely demonstrated In a real spacecraft? With humans?
  - m4rtink 2mo ago
    As I a say - a movie demonstrated how it would wourk & look like. As humman spaceflight goes, spin gravity has not been demonstrated in space yet. IIRC they wanted to try that with Gemini, same as with an early jet-pack, never actually got to it during that program. But effects of spin/circular motion have been demonstrated - Gemini 8 almost spun the crew to their death due to a stuck RCS thruster & Skylab astronauts made a video of them running around the inside of the big circular living space inside the station.
- adrian_b 2mo ago
  The cheaper alternative to having 2 spacecrafts connected by a cable is to replace one spacecraft with a counterweight. However, having 2 identical spacecrafts would be more reliable, as there would be more chances for at least one of them to remain completely functional over the entire duration of the journey.
adrian_b 2mo ago
The experiments recently done on mice on the ISS have concluded that, at least for them, around 1/3 of Earth gravity is the minimum required to preserve health. So providing only 1/5 g for artificial gravity is likely to be insufficient. Unfortunately, in the experiments with mice 1/3 g, like on Mars, was the minimum required to prevent severe health problems. For really having no health problems, 2/3 g was needed, i.e. more than on Mars. There are chances that the exploration of the Solar System by humans will not really be possible otherwise than in very big spaceships with good radiation shielding and artificial gravity, which would allow humans to stay on them for an indefinite time. Then for the exploration of Mars or of other planets, satellites or asteroids, such a big spaceship will stay in an orbit around that body and exploration teams will live on the surface only for short times, short enough to not be affected by the insufficient gravity. It is likely that such big spaceships would be practical only when propelled by nuclear reactors, assembled in an Earth orbit, or on the Moon. Or else, for living on Mars one would have to use underground bases where the habitable part would be rotating, to enhance the gravity.

by vitiral 2mo ago

Well, Mars has 1/3 of earth gravity so that helps. So for spinning the capsule, you only need say 1/5 earth gravity to be reasonably capable of walking on Mars. Does that help?

m4rtink 2mo ago

You can't really spin a small spacecraft to get rotation gravity - the rotation period would make it unworkable. However, you can connect two parts of your space craft with long cables and then spin the resulting contraption around its now center of rotation & the rotation period will be manageable. This concept has been nicely demonstrated & quite well popularized by the recent Project Hail Mary movie.

triceratops 2mo ago
> This concept has been nicely demonstrated In a real spacecraft? With humans?
- m4rtink 2mo ago
  As I a say - a movie demonstrated how it would wourk & look like. As humman spaceflight goes, spin gravity has not been demonstrated in space yet. IIRC they wanted to try that with Gemini, same as with an early jet-pack, never actually got to it during that program. But effects of spin/circular motion have been demonstrated - Gemini 8 almost spun the crew to their death due to a stuck RCS thruster & Skylab astronauts made a video of them running around the inside of the big circular living space inside the station.
adrian_b 2mo ago
The cheaper alternative to having 2 spacecrafts connected by a cable is to replace one spacecraft with a counterweight. However, having 2 identical spacecrafts would be more reliable, as there would be more chances for at least one of them to remain completely functional over the entire duration of the journey.

adrian_b 2mo ago

The experiments recently done on mice on the ISS have concluded that, at least for them, around 1/3 of Earth gravity is the minimum required to preserve health. So providing only 1/5 g for artificial gravity is likely to be insufficient. Unfortunately, in the experiments with mice 1/3 g, like on Mars, was the minimum required to prevent severe health problems. For really having no health problems, 2/3 g was needed, i.e. more than on Mars. There are chances that the exploration of the Solar System by humans will not really be possible otherwise than in very big spaceships with good radiation shielding and artificial gravity, which would allow humans to stay on them for an indefinite time. Then for the exploration of Mars or of other planets, satellites or asteroids, such a big spaceship will stay in an orbit around that body and exploration teams will live on the surface only for short times, short enough to not be affected by the insufficient gravity. It is likely that such big spaceships would be practical only when propelled by nuclear reactors, assembled in an Earth orbit, or on the Moon. Or else, for living on Mars one would have to use underground bases where the habitable part would be rotating, to enhance the gravity.