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The dangers of radiation on Mars are greatly exaggerated. The dangers of low gravity on Titan and elsewhere are greatly understated, as is the immense distance

The dangers of radiation on Mars are greatly exaggerated. The dangers of low gravity on Titan and elsewhere are greatly understated, as is the immense distance between Mars and Titan. A floating habitat on Venus is harder and less attractive in every way than a rotating space station, which is clearly our next milestone in space. In terms of planets though, there's a reason Mars gets the most attention: it's obviously the best choice.

Fjolsvith 7y ago
The distance would be mitigated with a 1g thrust drive. It would reduce the transit time between Earth and Mars to three days, with the ship accelerating to midpoint and decelerating from there. We just need a craft that can thrust that strength for three days straight.
- scrumbledober 7y ago
  A craft that can sustain a 1g thrust for three days straight is the most outlandish idea in this entire thread.
  - Fjolsvith 7y ago
    Maybe, but Phd's are thinking about it: https://www.johndcook.com/blog/2012/08/30/flying-to-mars-in-three-days/ https://www.johndcook.com/blog/2012/08/30/flying-to-mars-in-... and https://www.skythisweek.info/constant1g.pdf https://www.skythisweek.info/constant1g.pdf
    - scrumbledober 7y ago
      talking about how it would be cool if we had a ship that could do that, and the implications of that. In no way is anyone with any serious education actually talking about HOW to possibly get a craft with the mass fraction and specific impulse to pull this off. we are several orders of magnitude off of this being possible when it comes to specific impulse, and the highest impulse engines we have have nowhere near enough thrust to weight.
      - Fjolsvith 7y ago
        Seems there are several thruster designs aimed towards this goal: https://larouchepub.com/other/2019/4622-revolutionary_space_propulsion.html https://larouchepub.com/other/2019/4622-revolutionary_space_... And at NASA: https://www.nasa.gov/pdf/501329main_TA02-InSpaceProp-DRAFT-Nov2010-A.pdf https://www.nasa.gov/pdf/501329main_TA02-InSpaceProp-DRAFT-N... https://futurism.com/nasas-new-ion-thruster-breaks-records-could-take-humans-to-mars https://futurism.com/nasas-new-ion-thruster-breaks-records-c...
kjs3 7y ago
Unless you think that the Moon is the obvious next milestone in space.
- btkramer9 7y ago
  The only thing going for the moon is its proximity to Earth. Mars has more than double the gravity of the moon, an atmosphere, nearly earth-like day night cycle and satellites have a much easier time orbiting mars
  - theseadroid 7y ago
    And its proximity is probably the most important factor?
    - btkramer9 7y ago
      I'm not so sure about that. It takes more delta-v to get to the moon than mars and both are still too far for immediate response to emergencies. Sure the moon has the advantage of emergency assistance of a few days (?) but I don't think that's more valuable than all of Mars's pros
      - jbattle 7y ago
        > It takes more delta-v to get to the moon than mars Is that true? I can't see how that'd be true, unless maybe you are considering aerobraking to enter mars orbit and parachutes for landing on the surface (?)
        btkramer9 7y ago
        yes with aerobreaking but I still believe that includes a propulsive landing after. The moon has no atmosphere so it has to be propulsive landing 100%
        kjs3 7y ago
        It's hyperselective framing the argument: bork bork Delta-V bork...and let's just ignore the 6 months of travel time and logistics difference as though that doesn't exist. Then I get to be right!
anewguy9000 7y ago
references?
rootbear 7y ago
I, too, have concerns about how well humans will thrive in low gravity (the moon, Mars, etc). Over time, we could evolve a branch of humanity, "Homo ares", for Mars, but it won't be easy. Venus is just a tragic waste of a planet. So close to Earth in size, so wrong in every other way.
- btkramer9 7y ago
  I've always wondered if Venus was as habitable as Mars on the surface which we'd choose. The lower gravity well of Mars makes it much easier to come back from which is practically a requirement to go there. But like you said, the jury is still out on how well we can live in lower gravity. Getting back from Venus after just beginning to colonize it may not be possible with current technology.
  - logfromblammo 7y ago
    I would choose Venus. The depth of the gravity well is less important when the colonists are being lowered into it from above rather than thrown out from the bottom. If you need something in orbit, you don't drop it down to the planet in the first place. But as things are, the relative effort to terraform Venus, compared with Mars, is absolutely colossal. It essentially requires a full-blown robotic asteroid mining industry, wherein olivine asteroids are diverted directly to Venus, and magnesium and calcium are mined, sent to Jupiter to produce saturated hydrides, and those sent on to Venus. It will take 1000 years, minimum. Mars can get realistic results within 200 years, just by diverting water-ice comets and managing temperature.
  - magduf 7y ago
    Getting back from Venus is as easy as launching from Earth: i.e., completely doable with present-day technology. The only issue is getting it there to begin with, but that's not really hard, though we'd probably need to launch several rockets here on Earth, and assemble stuff in space, to get all the mass needed for a single launch on Venus. Landing stuff on this hypothetical Venus would be much easier than on Mars, since this Venus has an atmosphere, and Mars only has an "atmosphere" (one that's 1/200 the pressure of Earth's, not really much of one), so we'd be able to use aerobraking, parachutes, etc. In fact, landing stuff on today's Venus is pretty easy, and the Soviets were doing this ages ago; the only problem is that landers didn't last long because of the heat and corrosive atmosphere.
palisade 7y ago
A floating habitat on Venus is actually more attractive. Venus (upper atmosphere): -human livable temperatures with modest temperature control -Earth-like pressure (Himalayans) leads to slow leaks that can be patched, and pressure can be increased inside to stop the leaks inward -protected by thick atmosphere from radiation, meteors, asteroids -strong magnetic field against radiation -atmosphere still thin enough for solar panel energy use -the sulfuric acid atmosphere requires a Teflon coating and/or mixing Teflon particles with the metals during fabrication -the escape velocity from the upper atmosphere is low and requires a small rocket and not much fuel, leaving more fuel for return trips -distance between Earth and Venus is 3 months, versus 6 months to a 1 year depending on the window of opportunity.. that means you can rescue crews faster, get them supplies quicker, and replace crew sooner on Venus -oxygen on Venus has a strong lifting power, you can float entire heavy concrete and steel cities on massive platforms, think cloud city from Star Wars(tm) -aerodynamics work similarly to Earth; airships (dirigibles), airplanes, drones are all possible here Concept mission to Venus compliments of NASA: https://www.youtube.com/watch?v=0az7DEwG68A https://www.youtube.com/watch?v=0az7DEwG68A Mars: -inhospitable temperatures not suitable for human or plant life -explosive decompression due to a micro-meteorite causing a hole -no atmosphere to protect against radiation or projectiles -weak magnetic field providing no protection -violent unpredictable wind storms on the surface -unbreathable atmosphere -the escape velocity from Mars requires a massive rocket equivalent to the one we use to leave Earth and therefore more fuel leaving less payload for delivering other resources or supplies -the distance is 6 months to 1 year depending on the window of opportunity, leading to some NASA scientists to suggest we should find it acceptable that it as a suicide mission with no hope of return Rotating space station: -high risk from impacts -no atmosphere to protect against radiation or projectiles -no magnetic field providing no protection -danger from space debris from previous missions -no surrounding breathable atmosphere -close distance makes resupplying and re-crewing more tenable -requires constant fuel and attention to not de-orbit -does not establish a permanent residence -not a base of significant distance for further operations to the rest of the solar system
- ggffryuuj 7y ago
  Literally everything you said is wrong except projectiles and space stations. Magnetic fields are easy to make. Wind storms and unbreathable air and radiation and projectiles don’t matter if you’re underground. The idea that a floating city is better than a city cemented in soil is laughable. Good luck maintaining that Teflon coating on literally every exterior surface.

Fjolsvith 7y ago

The distance would be mitigated with a 1g thrust drive. It would reduce the transit time between Earth and Mars to three days, with the ship accelerating to midpoint and decelerating from there. We just need a craft that can thrust that strength for three days straight.

scrumbledober 7y ago
A craft that can sustain a 1g thrust for three days straight is the most outlandish idea in this entire thread.
- Fjolsvith 7y ago
  Maybe, but Phd's are thinking about it: https://www.johndcook.com/blog/2012/08/30/flying-to-mars-in-three-days/ https://www.johndcook.com/blog/2012/08/30/flying-to-mars-in-... and https://www.skythisweek.info/constant1g.pdf https://www.skythisweek.info/constant1g.pdf
  - scrumbledober 7y ago
    talking about how it would be cool if we had a ship that could do that, and the implications of that. In no way is anyone with any serious education actually talking about HOW to possibly get a craft with the mass fraction and specific impulse to pull this off. we are several orders of magnitude off of this being possible when it comes to specific impulse, and the highest impulse engines we have have nowhere near enough thrust to weight.
    - Fjolsvith 7y ago
      Seems there are several thruster designs aimed towards this goal: https://larouchepub.com/other/2019/4622-revolutionary_space_propulsion.html https://larouchepub.com/other/2019/4622-revolutionary_space_... And at NASA: https://www.nasa.gov/pdf/501329main_TA02-InSpaceProp-DRAFT-Nov2010-A.pdf https://www.nasa.gov/pdf/501329main_TA02-InSpaceProp-DRAFT-N... https://futurism.com/nasas-new-ion-thruster-breaks-records-could-take-humans-to-mars https://futurism.com/nasas-new-ion-thruster-breaks-records-c...

kjs3 7y ago

Unless you think that the Moon is the obvious next milestone in space.

btkramer9 7y ago
The only thing going for the moon is its proximity to Earth. Mars has more than double the gravity of the moon, an atmosphere, nearly earth-like day night cycle and satellites have a much easier time orbiting mars
- theseadroid 7y ago
  And its proximity is probably the most important factor?
  - btkramer9 7y ago
    I'm not so sure about that. It takes more delta-v to get to the moon than mars and both are still too far for immediate response to emergencies. Sure the moon has the advantage of emergency assistance of a few days (?) but I don't think that's more valuable than all of Mars's pros
    - jbattle 7y ago
      > It takes more delta-v to get to the moon than mars Is that true? I can't see how that'd be true, unless maybe you are considering aerobraking to enter mars orbit and parachutes for landing on the surface (?)
      - btkramer9 7y ago
        yes with aerobreaking but I still believe that includes a propulsive landing after. The moon has no atmosphere so it has to be propulsive landing 100%
      - kjs3 7y ago
        It's hyperselective framing the argument: bork bork Delta-V bork...and let's just ignore the 6 months of travel time and logistics difference as though that doesn't exist. Then I get to be right!

anewguy9000 7y ago

references?

rootbear 7y ago

I, too, have concerns about how well humans will thrive in low gravity (the moon, Mars, etc). Over time, we could evolve a branch of humanity, "Homo ares", for Mars, but it won't be easy. Venus is just a tragic waste of a planet. So close to Earth in size, so wrong in every other way.

btkramer9 7y ago
I've always wondered if Venus was as habitable as Mars on the surface which we'd choose. The lower gravity well of Mars makes it much easier to come back from which is practically a requirement to go there. But like you said, the jury is still out on how well we can live in lower gravity. Getting back from Venus after just beginning to colonize it may not be possible with current technology.
- logfromblammo 7y ago
  I would choose Venus. The depth of the gravity well is less important when the colonists are being lowered into it from above rather than thrown out from the bottom. If you need something in orbit, you don't drop it down to the planet in the first place. But as things are, the relative effort to terraform Venus, compared with Mars, is absolutely colossal. It essentially requires a full-blown robotic asteroid mining industry, wherein olivine asteroids are diverted directly to Venus, and magnesium and calcium are mined, sent to Jupiter to produce saturated hydrides, and those sent on to Venus. It will take 1000 years, minimum. Mars can get realistic results within 200 years, just by diverting water-ice comets and managing temperature.
- magduf 7y ago
  Getting back from Venus is as easy as launching from Earth: i.e., completely doable with present-day technology. The only issue is getting it there to begin with, but that's not really hard, though we'd probably need to launch several rockets here on Earth, and assemble stuff in space, to get all the mass needed for a single launch on Venus. Landing stuff on this hypothetical Venus would be much easier than on Mars, since this Venus has an atmosphere, and Mars only has an "atmosphere" (one that's 1/200 the pressure of Earth's, not really much of one), so we'd be able to use aerobraking, parachutes, etc. In fact, landing stuff on today's Venus is pretty easy, and the Soviets were doing this ages ago; the only problem is that landers didn't last long because of the heat and corrosive atmosphere.

palisade 7y ago

A floating habitat on Venus is actually more attractive. Venus (upper atmosphere): -human livable temperatures with modest temperature control -Earth-like pressure (Himalayans) leads to slow leaks that can be patched, and pressure can be increased inside to stop the leaks inward -protected by thick atmosphere from radiation, meteors, asteroids -strong magnetic field against radiation -atmosphere still thin enough for solar panel energy use -the sulfuric acid atmosphere requires a Teflon coating and/or mixing Teflon particles with the metals during fabrication -the escape velocity from the upper atmosphere is low and requires a small rocket and not much fuel, leaving more fuel for return trips -distance between Earth and Venus is 3 months, versus 6 months to a 1 year depending on the window of opportunity.. that means you can rescue crews faster, get them supplies quicker, and replace crew sooner on Venus -oxygen on Venus has a strong lifting power, you can float entire heavy concrete and steel cities on massive platforms, think cloud city from Star Wars(tm) -aerodynamics work similarly to Earth; airships (dirigibles), airplanes, drones are all possible here Concept mission to Venus compliments of NASA: https://www.youtube.com/watch?v=0az7DEwG68A https://www.youtube.com/watch?v=0az7DEwG68A Mars: -inhospitable temperatures not suitable for human or plant life -explosive decompression due to a micro-meteorite causing a hole -no atmosphere to protect against radiation or projectiles -weak magnetic field providing no protection -violent unpredictable wind storms on the surface -unbreathable atmosphere -the escape velocity from Mars requires a massive rocket equivalent to the one we use to leave Earth and therefore more fuel leaving less payload for delivering other resources or supplies -the distance is 6 months to 1 year depending on the window of opportunity, leading to some NASA scientists to suggest we should find it acceptable that it as a suicide mission with no hope of return Rotating space station: -high risk from impacts -no atmosphere to protect against radiation or projectiles -no magnetic field providing no protection -danger from space debris from previous missions -no surrounding breathable atmosphere -close distance makes resupplying and re-crewing more tenable -requires constant fuel and attention to not de-orbit -does not establish a permanent residence -not a base of significant distance for further operations to the rest of the solar system

ggffryuuj 7y ago
Literally everything you said is wrong except projectiles and space stations. Magnetic fields are easy to make. Wind storms and unbreathable air and radiation and projectiles don’t matter if you’re underground. The idea that a floating city is better than a city cemented in soil is laughable. Good luck maintaining that Teflon coating on literally every exterior surface.