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I just realized something. Supposing we ever colonize Mars (lol!), helicopters and planes won't work there. That means long-distant transport will be either by

I just realized something. Supposing we ever colonize Mars (lol!), helicopters and planes won't work there. That means long-distant transport will be either by ground or by reusable ballistic rocket. I'm sure that's not a surprise to anyone but me, but I think it would be an interesting contribution to e.g. setting an old western on Mars.

rbanffy 5y ago
> helicopters and planes won't work there. They could, provided they have very large wings. Lower gravity helps, but near vacuum on the surface, winds and dust storms are problematic. OTOH, SSTO is easier on Mars and there will be quite a surplus of rocket engines, at least at the start of the colonization effort. Suborbitals are much easier. Finally, I think settlements will tend to be closer to each other because it's easier to manage emergencies when one does not require air travel.
- dsr_ 5y ago
  Mars is, by Earth's standard, tectonically inactive. You should not expect dangerous marsquakes. Mars is hydrologically impoverished: you should not expect flooding. Meteorite impacts might be more severe because of the reduced atmosphere, so more small impacts should be expected. Medium and large impacts should be about the same: rare. The biggest problems on Mars are air, water, and temperature. All of these have scalar efficiencies, so I suspect an optimal arrangement for Mars would be three cities not very far from each other, so as to be able to provide mutual support while avoiding single points of failure.
  - rbanffy 5y ago
    Lava tubes can provide adequate protection against radiation and small impacts. Inflatables can provide additional mechanical support for the tube walls and offer space for huge areas (which are not that great an idea, for redundancy reasons).
    - stjohnswarts 5y ago
      So how exactly would you know where said lava tubes exist?
      - rbanffy 5y ago
        We found a couple: https://planetary-science.org/research/prospective-lava-tubes-at-hellas-planitia/ https://planetary-science.org/research/prospective-lava-tube... https://mars.nasa.gov/resources/26349/hirise-spots-the-mouth-of-a-martian-lava-tube/ https://mars.nasa.gov/resources/26349/hirise-spots-the-mouth...
  - abhaynayar 5y ago
    > marsquakes I thought you made that term up, but apparently not: https://en.wikipedia.org/wiki/Marsquake https://en.wikipedia.org/wiki/Marsquake And some more quakes: https://en.wikipedia.org/wiki/Quake_(natural_phenomenon) https://en.wikipedia.org/wiki/Quake_(natural_phenomenon)
- TremendousJudge 5y ago
  Or airships as well
  - rbanffy 5y ago
    Wind is a problem. Even with low pressure, the speeds are high enough to create some forces.
spaetzleesser 5y ago
They could do hyperloops . Pressure is already low so vacuum tubes maybe easier.
ur-whale 5y ago
Hence the Boring Company
burkaman 5y ago
Or vacuumships? https://www.nasa.gov/directorates/spacetech/niac/2017_Phase_I_Phase_II/Evacuated_Airship_for_Mars_Missions/ https://www.nasa.gov/directorates/spacetech/niac/2017_Phase_...
jessriedel 5y ago
High-speed rail on Mars will have all the advantages of hyperloop (greatly reduced drag from 1% atmosphere) with none of the downsides (the cost of building miles of enclosed tubing and keeping it evacuated). At Marian sea level you could travel by rail much faster than an airplane at 30k feet on Earth. Only downside relative to air travel on Earth would be building out the track.
- ethagknight 5y ago
  Don't really need the rail, same benefits apply to a 'paved' road.
  - DiggyJohnson 5y ago
    Mad Max showed us the way.
  - kbelder 5y ago
    1/3rd the surface gravity... steering, accelerating, and braking will have some unique challenges.
  - jessriedel 5y ago
    Well, just as on Earth, there are cases where pavement for wheeled vehicles makes sense and cases where trains on tracks makes sense. But I expect rail will be more widely deployed on Mars since typical travel speeds will be higher on account of the thinner atmosphere. Going 300 mph by rail would be a snap, but you'd need awfully smooth and wide pavement, and a steady hand, to drive that fast on Mars. And going significantly faster will require levitation, where there isn't any advantage to not using a track.
- 6gvONxR4sf7o 5y ago
  > At Marian sea level Well thanks for nerd sniping me! This got me googling, and the closest thing to a martian sea level turns out to be super interesting. And so I’ll share the interesting stuff I just learned. Since mars doesn’t have a sea, there’s no easy sea level equivalent, so (if I understand correctly) they have a level called the aeroid [0] (the corresponding term for earth’s sea level is geoid. ‘aer’ for Ares, I suppose). At first, this was defined in terms of the level with a specific constant atmospheric pressure, but in 2001, ‘they’ made a new convention based on constant gravitational+rotational potential, since they finally had that data. So now mars ‘sea level’ is that “equipotential [constant potential] surface… whose average value at the equator is equal to the mean radius of the planet.” [1] …Thank you for coming to my ted talk. [0] https://en.wikipedia.org/wiki/Gravity_of_Mars#Areoid https://en.wikipedia.org/wiki/Gravity_of_Mars#Areoid [1] https://en.wikipedia.org/wiki/Geography_of_Mars#Zero_elevation https://en.wikipedia.org/wiki/Geography_of_Mars#Zero_elevati...
Melatonic 5y ago
Not necessarily true - I can see some combo of a Zeppelin and a helicopter or prop powered plane like thing being workable. It may not be as fast as planes we have today but it would likely also have a huge efficiency advantage.
panick21_ 5y ago
Why?
guenthert 5y ago
> Supposing we ever colonize Mars (lol!), helicopters and planes won't work there. Quite a bold statement in a thread celebrating the 22nd successful flight of a helicopter on Mars.
- jml7c5 5y ago
  It's fairly clear they are referring to passenger-carrying helicopters and planes.

rbanffy 5y ago

> helicopters and planes won't work there. They could, provided they have very large wings. Lower gravity helps, but near vacuum on the surface, winds and dust storms are problematic. OTOH, SSTO is easier on Mars and there will be quite a surplus of rocket engines, at least at the start of the colonization effort. Suborbitals are much easier. Finally, I think settlements will tend to be closer to each other because it's easier to manage emergencies when one does not require air travel.

dsr_ 5y ago
Mars is, by Earth's standard, tectonically inactive. You should not expect dangerous marsquakes. Mars is hydrologically impoverished: you should not expect flooding. Meteorite impacts might be more severe because of the reduced atmosphere, so more small impacts should be expected. Medium and large impacts should be about the same: rare. The biggest problems on Mars are air, water, and temperature. All of these have scalar efficiencies, so I suspect an optimal arrangement for Mars would be three cities not very far from each other, so as to be able to provide mutual support while avoiding single points of failure.
- rbanffy 5y ago
  Lava tubes can provide adequate protection against radiation and small impacts. Inflatables can provide additional mechanical support for the tube walls and offer space for huge areas (which are not that great an idea, for redundancy reasons).
  - stjohnswarts 5y ago
    So how exactly would you know where said lava tubes exist?
    - rbanffy 5y ago
      We found a couple: https://planetary-science.org/research/prospective-lava-tubes-at-hellas-planitia/ https://planetary-science.org/research/prospective-lava-tube... https://mars.nasa.gov/resources/26349/hirise-spots-the-mouth-of-a-martian-lava-tube/ https://mars.nasa.gov/resources/26349/hirise-spots-the-mouth...
- abhaynayar 5y ago
  > marsquakes I thought you made that term up, but apparently not: https://en.wikipedia.org/wiki/Marsquake https://en.wikipedia.org/wiki/Marsquake And some more quakes: https://en.wikipedia.org/wiki/Quake_(natural_phenomenon) https://en.wikipedia.org/wiki/Quake_(natural_phenomenon)
TremendousJudge 5y ago
Or airships as well
- rbanffy 5y ago
  Wind is a problem. Even with low pressure, the speeds are high enough to create some forces.

spaetzleesser 5y ago

They could do hyperloops . Pressure is already low so vacuum tubes maybe easier.

ur-whale 5y ago

Hence the Boring Company

burkaman 5y ago

Or vacuumships? https://www.nasa.gov/directorates/spacetech/niac/2017_Phase_I_Phase_II/Evacuated_Airship_for_Mars_Missions/ https://www.nasa.gov/directorates/spacetech/niac/2017_Phase_...

jessriedel 5y ago

High-speed rail on Mars will have all the advantages of hyperloop (greatly reduced drag from 1% atmosphere) with none of the downsides (the cost of building miles of enclosed tubing and keeping it evacuated). At Marian sea level you could travel by rail much faster than an airplane at 30k feet on Earth. Only downside relative to air travel on Earth would be building out the track.

ethagknight 5y ago
Don't really need the rail, same benefits apply to a 'paved' road.
- DiggyJohnson 5y ago
  Mad Max showed us the way.
- kbelder 5y ago
  1/3rd the surface gravity... steering, accelerating, and braking will have some unique challenges.
- jessriedel 5y ago
  Well, just as on Earth, there are cases where pavement for wheeled vehicles makes sense and cases where trains on tracks makes sense. But I expect rail will be more widely deployed on Mars since typical travel speeds will be higher on account of the thinner atmosphere. Going 300 mph by rail would be a snap, but you'd need awfully smooth and wide pavement, and a steady hand, to drive that fast on Mars. And going significantly faster will require levitation, where there isn't any advantage to not using a track.
6gvONxR4sf7o 5y ago
> At Marian sea level Well thanks for nerd sniping me! This got me googling, and the closest thing to a martian sea level turns out to be super interesting. And so I’ll share the interesting stuff I just learned. Since mars doesn’t have a sea, there’s no easy sea level equivalent, so (if I understand correctly) they have a level called the aeroid [0] (the corresponding term for earth’s sea level is geoid. ‘aer’ for Ares, I suppose). At first, this was defined in terms of the level with a specific constant atmospheric pressure, but in 2001, ‘they’ made a new convention based on constant gravitational+rotational potential, since they finally had that data. So now mars ‘sea level’ is that “equipotential [constant potential] surface… whose average value at the equator is equal to the mean radius of the planet.” [1] …Thank you for coming to my ted talk. [0] https://en.wikipedia.org/wiki/Gravity_of_Mars#Areoid https://en.wikipedia.org/wiki/Gravity_of_Mars#Areoid [1] https://en.wikipedia.org/wiki/Geography_of_Mars#Zero_elevation https://en.wikipedia.org/wiki/Geography_of_Mars#Zero_elevati...

Melatonic 5y ago

Not necessarily true - I can see some combo of a Zeppelin and a helicopter or prop powered plane like thing being workable. It may not be as fast as planes we have today but it would likely also have a huge efficiency advantage.

panick21_ 5y ago

Why?

guenthert 5y ago

> Supposing we ever colonize Mars (lol!), helicopters and planes won't work there. Quite a bold statement in a thread celebrating the 22nd successful flight of a helicopter on Mars.

jml7c5 5y ago
It's fairly clear they are referring to passenger-carrying helicopters and planes.