Everyday Life in SF: Exploring Realistic Possibilities

[mfb]

UV is easily blocked by most types of glass.

Phobos has 2.14 km/s average orbital velocity at a semi-major axis of 2.76 times the Mars radius. A skyhook hanging from Phobos would have a speed of about 1 km/s a few hundred kilometers above the Martian surface. At ~5500 km length and 0 to 0.4 g gravitational acceleration, it is probably something that can be deployed in a single piece with a moderate tapering ratio with current materials. How to dock to such a tether? Who knows.

 

[Noisy Rhysling]

UV is easily blocked by most types of glass.

Phobos has 2.14 km/s average orbital velocity at a semi-major axis of 2.76 times the Mars radius. A skyhook hanging from Phobos would have a speed of about 1 km/s a few hundred kilometers above the Martian surface. At ~5500 km length and 0 to 0.4 g gravitational acceleration, it is probably something that can be deployed in a single piece with a moderate tapering ratio with current materials. How to dock to such a tether? Who knows.

Have you ever seen "Aeon Flux"?

 

[GTOM]

Have you ever seen "Aeon Flux"?

Havent seen that, or heard good reviews about it.
Martians will surely have serious UV-blocking glass, X-rays are nastier, during solar storms, they get their rad dose.

So they should be rather pale, and have increased cancer risks (compensated by more freedom or bigger share of the pie)

 

[Noisy Rhysling]

Havent seen that, or heard good reviews about it.
Martians will surely have serious UV-blocking glass, X-rays are nastier, during solar storms, they get their rad dose.

So they should be rather pale, and have increased cancer risks (compensated by more freedom or bigger share of the pie)

There's one sequence in the movie where Aeon needs to get up to the giant balloon-thingy. Just so happens that it trails long streamers (for no apparent reason). She climbs a tall structure and jumps to catch the streamers, then hoists herself up via that route.

That's a low level demonstration of how I see the elevator working. Its "streamer" is just outside the atmosphere, and Martians would use a shuttle to meet that. From there a somewhat conventional elevator takes the passengers up to Phobos. The elevators are paired, one going up with another goes down, so the only power needed is lift the mass of the passengers.

(As for the movie, I didn't read the comic book, so I didn't go in hating the movie.)

 

[mfb]

Martians will surely have serious UV-blocking glass, X-rays are nastier, during solar storms, they get their rad dose.

Everything that shields against cosmic rays will easily shield everything that comes from the Sun. Just don't go out when a solar storm is approaching.

The elevators are paired, one going up with another goes down, so the only power needed is lift the mass of the passengers.

By moving the whole cable? That is impractical and wouldn't work with current materials. Make them go up/down with electric motors.

 

[Noisy Rhysling]

Everything that shields against cosmic rays will easily shield everything that comes from the Sun. Just don't go out when a solar storm is approaching.By moving the whole cable? That is impractical and wouldn't work with current materials. Make them go up/down with electric motors.

The main cable is ultra-strong. The elevator cables ride that cable. One cable, each end attached to an elevator. The weight of cars cancel out.

And I'm very sure we're not working with "current materials" on this.

 

[mfb]

Where is the point in a "main cable" if the elevator cable holds the payload?

And I'm very sure we're not working with "current materials" on this.

But we could build this with current materials. Just not with the setup you imagine, which doesn't help and makes everything way more difficult.

 

[Noisy Rhysling]

If you say so.

 

[GTOM]

If you say so.

I also think, it is easier if only the elevator cabins moving, not the whole thousands kms cables.

 

[Noisy Rhysling]

In that system power is needed to move the cabins and their contents. In a counterweight system you just need to move the weight of the contents.

 

[GTOM]

In that system power is needed to move the cabins and their contents. In a counterweight system you just need to move the weight of the contents.

And the thousand km cable between the two.

 

[Noisy Rhysling]

And the thousand km cable between the two.

Pity the engineers didn't figure that in.

 

[mfb]

You have to move the whole mass of the cable, exceeding the mass of the payload by a factor of10 to 1000, depending on the implementation. Even worse, tapering gets much more complicated if you want to move cables and you need hours to start and stop the system without undue stress in the cable.

This is not your typical building elevator where the cables are just a convenient tool to hold the cabin. The cables are thousands of kilometers long and have much more mass than the cabin itself. Moving the cables around is extremely impractical.

 

[GTOM]

https://phys.org/news/2017-09-lava-tubes-hidden-sites-future.html

Found that one. Although it looks like, it isn't absolutely sure, that such large caves exists, just assumed.

Based on the article, it looks like a martian cavern wouldn't be enough for capital (that would be a domed city at equator, i think a MW laser enough for anti meteor protection), but it would be good for a mining town.