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Radiation is a huge problem. Both en route and on Mars. A lot of these problems beg the question. Is Mars really the best target? Sure it's close but there

Radiation is a huge problem. Both en route and on Mars. A lot of these problems beg the question. Is Mars really the best target? Sure it's close but there are moons around Saturn that are interesting as well. Titan for example. Sure it's cold but it has a lot of atmosphere. Presumably landing would be easier. If we could learn to live underwater we could possibly visit Ganymede or Europa.

semi-extrinsic 10y ago
Radiation, as you mention, is a very big problem which is independent of destination. Human psychology is another, perhaps even bigger problem, also independent of destination. We've had various experiments with prolonged isolation, but none where the subjects know that they're never coming back to Earth. I'd say psychology has a >50% chance of wrecking the first manned missions to other planets/moons, unless we send huge ships with hundreds of people. In the Red Mars trilogy by Kim Stanley Robinson, the author has come to the very astute observation that a) no perfectly rational, mentally healthy human would volunteer for such a mission b) there will necessarily be extensive psychological screening to ensure we only send rational people thus c) the people who will be selected are likely to be non-rational actors very good at concealing their non-rationality from psychologists. Also known as people with psychopathic tendencies.
- coldtea 10y ago
  >Human psychology is another, perhaps even bigger problem, also independent of destination. We've had various experiments with prolonged isolation, but none where the subjects know that they're never coming back to Earth. Who said they're never coming back to Earth? >no perfectly rational, mentally healthy human would volunteer for such a mission That's an easy problem to solve, as there are no "perfectly rational" and/or absolutely "mentally healthy humans", and have never been anyway. And people can still be quite rational and mentally healthy and yet cherish the possibility to take such a mission, even if there's a possibility to die, etc. In fact, it's needs no more troubled people than those that go to the army and are OK to be sent to war, or people that dive and explore the oceans, etc etc.
  - semi-extrinsic 10y ago
    How are they going to come back? All realistic plans I've seen are for one-way trips. The thought of dying isn't the inherently problematic part, but rather the extreme isolation. People who go to war are there for only some months and have plans for going home, back to friends and family. People who dive and explore the oceans are isolated for a few days at worst; perhaps months in a nuclear sub, but there you have already a pretty large crew around you. Compared to decades spent isolated with a handful of people, and no return ticket to the rest of humanity, those are nothing.
    - coldtea 10y ago
      >How are they going to come back? All realistic plans I've seen are for one-way trips. Huh? "The first crewed Mars mission would be expected to have approximately 12 people, with the primary goal to "build out and troubleshoot the propellant plant and Mars Base Alpha power system" as well as a" rudimentary base." In the event of an emergency, the spaceship would be able to return to Earth without having to wait a full 26 months for the next synodic period." https://en.wikipedia.org/wiki/Interplanetary_Transport_System#Mars_early_missions https://en.wikipedia.org/wiki/Interplanetary_Transport_Syste...
      - chandmer 10y ago
        Yep. The spaceship has to come back at the very least.
    - namlem 10y ago
      What are you talking about? Both NASA's and Musk's plans involve return trips.
      - semi-extrinsic 10y ago
        Wow, that is so hard I didn't think it was being seriously considered. They're going to send a Mars surface-to-orbit launcher as payload in one piece, without fuel, and then produce >30 tons of rocket fuel on Mars? My hat's off to them.
- LeifCarrotson 10y ago
  > no perfectly rational, mentally healthy human would volunteer for such a mission That depends entirely on what they value. If they value their own safety, comfort, and health, then it wouldn't be rational for them. But if they value the advancement of future humans, honor, fame, legacy, scientific discovery, adventure, and so on (which may seem to be irrational things to value for someone in the first group) then it would be rational. There are some people who will be excited about the fictitious ad from Earnest Shackelton "Men wanted for hazardous journey, small wages, and bitter cold, long months of complete darkness, constant danger, safe return doubtful, honor and recognition in case of success."
- Jeema101 10y ago
  Exactly. Who is going to want to live underground in a freezing wasteland for the rest of their lives after the initial novelty of 'being on Mars' wears off? Nobody even does that here on Earth, so why would they want to do it on Mars? Floating around in aerostats on the cloud tops of Venus where it's roughly room temperature at 1 atm on the other hand... or living on the Moon where you can at least communicate with Earth in roughly real-time and are only 3 days away...
coldtea 10y ago
>A lot of these problems beg the question. Is Mars really the best target? Sure it's close but there are moons around Saturn that are interesting as well. You seem to imply that the issue of radiation should cause us to reconsider whether Mars is worth it. But the same, and worse, problem people will have with Saturn too.
- jcoffland 10y ago
  No, I mean all the problems taken together.
IndianAstronaut 10y ago
Titan may be a very good bet. It has an atmosphere so you aren't worrying if your water resources may boil away, or if a small tear in your suit hapens, you have more time to fix the situation.
- chandmer 10y ago
  Titan is super cool, and also freezing. I think it falls into the "need infinite fusion" bin, but after that, sure!
nine_k 10y ago
A floating station (eventually a city?) in the atmosphere of Venus would also be fine. On certain height, the temperature and the pressure are close to Earth's surface, and sun shines brightly enough for plants to generate oxygen. There's plenty of carbon dioxide in the atmosphere to feed the plants. No roaming over the surface, though.
- chandmer 10y ago
  No access to generic raw materials and huge lifting gas overhead, even huger delta-V requirements to do anything. I don't get Venus cloud tops. I've never seen anyone explain how to transport, fuel and launch a Saturn V rocket from a zeppelin.
  - nine_k 10y ago
    The access to solids is definitely a problem. One approach might be digging them from the surface and lifting up using balloons. High temperatures don't help, but without the need to stay on the surface for very long periods, the digging robots may probably accumulate enough cold while high in the atmosphere, and then dive down for a short while, managing the temperature e.g. by melting and boiling the coolant, then go up again. The lifting gas can be initially transported in a highly pressurized form (e.g. liquid helium). It would be enough to support a small initial platform. That platform can generate lighter gases right from the atmosphere, using solar energy. CO2 is pretty heavy, so even oxygen and nitrogen would be lifting gases. Hydrogen is also somehow available for extraction from the atmosphere. These gases could be used to support more and more incoming structures as they arrive from orbit. (Yes, easier said than done.) The bigger problem would probably be compounds like sulfuric acid, hydrogen chloride and fluoride, etc, that would readily react with many construction materials, especially metals. Given the atmosphere composition, it's probably even possible to synthesize both fuel and oxidizer for a rocket, e.g. hydrocarbons and O2 or HNO3. Launching a large rocket from a zeppelin is tricky. Launching a rocket from a plane has been shown to work on Earth, so it's possibly also doable from Venusian cloud tops. Again, easier said than done. But still possible!
    - 10y ago
restalis 10y ago
"Is Mars really the best target? Sure it's close but there are moons around Saturn that are interesting as well. Titan for example." First, for what is worth, I share your Mars questioning. But then I can't just let you downplay the distance factor with "sure it's close" glossing-over. One can find interesting tools out there¹ that may help grasping the astronomical distances better. The bottom line is that it just makes more sense to take our chances with planets closer to us and so far, at least with the landing on Moon, the humans respected in this regard their species' "rational" self designation. ¹ http://joshworth.com/dev/pixelspace/pixelspace_solarsystem.html#earthtxt http://joshworth.com/dev/pixelspace/pixelspace_solarsystem.h...

semi-extrinsic 10y ago

Radiation, as you mention, is a very big problem which is independent of destination. Human psychology is another, perhaps even bigger problem, also independent of destination. We've had various experiments with prolonged isolation, but none where the subjects know that they're never coming back to Earth. I'd say psychology has a >50% chance of wrecking the first manned missions to other planets/moons, unless we send huge ships with hundreds of people. In the Red Mars trilogy by Kim Stanley Robinson, the author has come to the very astute observation that a) no perfectly rational, mentally healthy human would volunteer for such a mission b) there will necessarily be extensive psychological screening to ensure we only send rational people thus c) the people who will be selected are likely to be non-rational actors very good at concealing their non-rationality from psychologists. Also known as people with psychopathic tendencies.

coldtea 10y ago
>Human psychology is another, perhaps even bigger problem, also independent of destination. We've had various experiments with prolonged isolation, but none where the subjects know that they're never coming back to Earth. Who said they're never coming back to Earth? >no perfectly rational, mentally healthy human would volunteer for such a mission That's an easy problem to solve, as there are no "perfectly rational" and/or absolutely "mentally healthy humans", and have never been anyway. And people can still be quite rational and mentally healthy and yet cherish the possibility to take such a mission, even if there's a possibility to die, etc. In fact, it's needs no more troubled people than those that go to the army and are OK to be sent to war, or people that dive and explore the oceans, etc etc.
- semi-extrinsic 10y ago
  How are they going to come back? All realistic plans I've seen are for one-way trips. The thought of dying isn't the inherently problematic part, but rather the extreme isolation. People who go to war are there for only some months and have plans for going home, back to friends and family. People who dive and explore the oceans are isolated for a few days at worst; perhaps months in a nuclear sub, but there you have already a pretty large crew around you. Compared to decades spent isolated with a handful of people, and no return ticket to the rest of humanity, those are nothing.
  - coldtea 10y ago
    >How are they going to come back? All realistic plans I've seen are for one-way trips. Huh? "The first crewed Mars mission would be expected to have approximately 12 people, with the primary goal to "build out and troubleshoot the propellant plant and Mars Base Alpha power system" as well as a" rudimentary base." In the event of an emergency, the spaceship would be able to return to Earth without having to wait a full 26 months for the next synodic period." https://en.wikipedia.org/wiki/Interplanetary_Transport_System#Mars_early_missions https://en.wikipedia.org/wiki/Interplanetary_Transport_Syste...
    - chandmer 10y ago
      Yep. The spaceship has to come back at the very least.
  - namlem 10y ago
    What are you talking about? Both NASA's and Musk's plans involve return trips.
    - semi-extrinsic 10y ago
      Wow, that is so hard I didn't think it was being seriously considered. They're going to send a Mars surface-to-orbit launcher as payload in one piece, without fuel, and then produce >30 tons of rocket fuel on Mars? My hat's off to them.
LeifCarrotson 10y ago
> no perfectly rational, mentally healthy human would volunteer for such a mission That depends entirely on what they value. If they value their own safety, comfort, and health, then it wouldn't be rational for them. But if they value the advancement of future humans, honor, fame, legacy, scientific discovery, adventure, and so on (which may seem to be irrational things to value for someone in the first group) then it would be rational. There are some people who will be excited about the fictitious ad from Earnest Shackelton "Men wanted for hazardous journey, small wages, and bitter cold, long months of complete darkness, constant danger, safe return doubtful, honor and recognition in case of success."
Jeema101 10y ago
Exactly. Who is going to want to live underground in a freezing wasteland for the rest of their lives after the initial novelty of 'being on Mars' wears off? Nobody even does that here on Earth, so why would they want to do it on Mars? Floating around in aerostats on the cloud tops of Venus where it's roughly room temperature at 1 atm on the other hand... or living on the Moon where you can at least communicate with Earth in roughly real-time and are only 3 days away...

coldtea 10y ago

>A lot of these problems beg the question. Is Mars really the best target? Sure it's close but there are moons around Saturn that are interesting as well. You seem to imply that the issue of radiation should cause us to reconsider whether Mars is worth it. But the same, and worse, problem people will have with Saturn too.

jcoffland 10y ago
No, I mean all the problems taken together.

IndianAstronaut 10y ago

Titan may be a very good bet. It has an atmosphere so you aren't worrying if your water resources may boil away, or if a small tear in your suit hapens, you have more time to fix the situation.

chandmer 10y ago
Titan is super cool, and also freezing. I think it falls into the "need infinite fusion" bin, but after that, sure!

nine_k 10y ago

A floating station (eventually a city?) in the atmosphere of Venus would also be fine. On certain height, the temperature and the pressure are close to Earth's surface, and sun shines brightly enough for plants to generate oxygen. There's plenty of carbon dioxide in the atmosphere to feed the plants. No roaming over the surface, though.

chandmer 10y ago
No access to generic raw materials and huge lifting gas overhead, even huger delta-V requirements to do anything. I don't get Venus cloud tops. I've never seen anyone explain how to transport, fuel and launch a Saturn V rocket from a zeppelin.
- nine_k 10y ago
  The access to solids is definitely a problem. One approach might be digging them from the surface and lifting up using balloons. High temperatures don't help, but without the need to stay on the surface for very long periods, the digging robots may probably accumulate enough cold while high in the atmosphere, and then dive down for a short while, managing the temperature e.g. by melting and boiling the coolant, then go up again. The lifting gas can be initially transported in a highly pressurized form (e.g. liquid helium). It would be enough to support a small initial platform. That platform can generate lighter gases right from the atmosphere, using solar energy. CO2 is pretty heavy, so even oxygen and nitrogen would be lifting gases. Hydrogen is also somehow available for extraction from the atmosphere. These gases could be used to support more and more incoming structures as they arrive from orbit. (Yes, easier said than done.) The bigger problem would probably be compounds like sulfuric acid, hydrogen chloride and fluoride, etc, that would readily react with many construction materials, especially metals. Given the atmosphere composition, it's probably even possible to synthesize both fuel and oxidizer for a rocket, e.g. hydrocarbons and O2 or HNO3. Launching a large rocket from a zeppelin is tricky. Launching a rocket from a plane has been shown to work on Earth, so it's possibly also doable from Venusian cloud tops. Again, easier said than done. But still possible!
  - 10y ago

restalis 10y ago

"Is Mars really the best target? Sure it's close but there are moons around Saturn that are interesting as well. Titan for example." First, for what is worth, I share your Mars questioning. But then I can't just let you downplay the distance factor with "sure it's close" glossing-over. One can find interesting tools out there¹ that may help grasping the astronomical distances better. The bottom line is that it just makes more sense to take our chances with planets closer to us and so far, at least with the landing on Moon, the humans respected in this regard their species' "rational" self designation. ¹ http://joshworth.com/dev/pixelspace/pixelspace_solarsystem.html#earthtxt http://joshworth.com/dev/pixelspace/pixelspace_solarsystem.h...