4 ms·

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 mil

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...

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...