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Completely off-topic, but what's the latest thinking on space-elevators? Is there any active research on them? I thought that carbon nanotubes or diamond nano

Completely off-topic, but what's the latest thinking on space-elevators? Is there any active research on them? I thought that carbon nanotubes or diamond nanothreads were likely candidates for the cable material.

ori_b 10y ago
Materials science isn't there yet, and the investigation is still in the more general material research phase. We're decades off. You're asking about the state of supersonic air travel while researchers are still figuring out how to smelt aluminum.
geuis 10y ago
Still a lot of active research going on. The biggest issues that need to be resolved are currently with the cable material. There has been a surprising amount of progress in the last few years with creating longer carbon fibers, but its still nascent and has a minimum of 5-10 years of work. Probably much more. Then even when the cable strength and length issues are satisfactorily resolved, there are lots of other logistics to deal with. I think any future barriers to the elevator(s) will be more regulatory than technological in the future.
- aetherson 10y ago
  I'm not sure what "future barriers to the elevator(s) will be more regulatory than technological" means. Like, right now, the barriers are firmly technological. From the perspective of a hypothetical future in which all the technological problems have been solved, the barriers might be regulatory. But that seems tautological.
oliwaw 10y ago
Probably the biggest barrier to space elevators is exactly what SpaceX and Blue Origin are doing - safe, reliable, and eventually (relatively) inexpensive rockets will make the large fixed costs of setting up a space elevator uneconomical.
- planteen 10y ago
  It seems like there is a wall in reliability with getting chemical rockets much more reliable than about 99% - 99.5%. SpaceX and Blue Origin are doing cool things, but I don't see them being any more reliable than previous generations of chemical rockets. If an elevator could provide more 9s of reliability, that could be huge.
  - oliwaw 10y ago
    But cost is also at issue. For cargo, it might make sense to take on 0.5-1.0% risk versus the massive investments necessary for the development of a space elevator. And when we're talking about human spaceflight, consider the work SpaceX and Blue are putting into in-flight abort and propulsive landing - SpaceX's Crew Dragon should be much safer than the Space Shuttle, for example.
    - planteen 10y ago
      Yeah for cargo I agree. I was thinking more along the lines for human rating. Propulsive landing helps for some failure modes but not all. Like I don't think it would have helped the CRS-7 failure had that been manned.
      - hLHEDuYtSh 10y ago
        It actually would have helped on CRS-7 -- That capsule was fine until it hit the water. https://www.nasaspaceflight.com/2015/07/saving-spaceship-dragon-contingency-chute/ https://www.nasaspaceflight.com/2015/07/saving-spaceship-dra...
        deleted 10y ago
        [deleted]
- chriswarbo 10y ago
  I think that the best long term way to spur investment in projects like a space elevator would be to make space as economically attractive as possible. In-situ resources, extracted/processed robotically and accessed via low cost rockets is the way to do that. Once we have a rocket-powered transport network between, say, Earth-orbiting space stations, a moon colony, some near-Earth asteroid mines, fuel depots at lagrange points, a Phobos outpost and robotic factories on Mars, the economic payoff of a space elevator will be more immediate. Plus we could try them out on less massive bodies first, like the moon.
astazangasta 10y ago
The issues are huge and probably insurmountable. For example: where would you site it? It has to be equatorial so it can be below the geostationary counterweight. Just the motion of the cable from the eccentricity in the earth's rotation and orbit would probably tear the cable apart (imagine what the foundation of the base station would have to be, and how it would buckle and lift as the earth rotates). The space elevator is an idea that sounds cool but is fucking dumb if you think about it for more than ten minutes, like the idea of accelerating ships to near light speed, when every hydrogen atom in the void will shred your hull like a cosmic ray.
anubisresources 10y ago
They make no sense when compared with alternate method like launch loops, which can be built with current tech
- _archon_ 10y ago
  80km high track supported by centrifugal force and belt momentum, and tethered by (the same type of cable necessary for a space elevator)? With a belt over 4000 km long capable of 14km/sec without flying apart or overheating? Which part of this is current tech?

ori_b 10y ago

Materials science isn't there yet, and the investigation is still in the more general material research phase. We're decades off. You're asking about the state of supersonic air travel while researchers are still figuring out how to smelt aluminum.

geuis 10y ago

Still a lot of active research going on. The biggest issues that need to be resolved are currently with the cable material. There has been a surprising amount of progress in the last few years with creating longer carbon fibers, but its still nascent and has a minimum of 5-10 years of work. Probably much more. Then even when the cable strength and length issues are satisfactorily resolved, there are lots of other logistics to deal with. I think any future barriers to the elevator(s) will be more regulatory than technological in the future.

aetherson 10y ago
I'm not sure what "future barriers to the elevator(s) will be more regulatory than technological" means. Like, right now, the barriers are firmly technological. From the perspective of a hypothetical future in which all the technological problems have been solved, the barriers might be regulatory. But that seems tautological.

oliwaw 10y ago

Probably the biggest barrier to space elevators is exactly what SpaceX and Blue Origin are doing - safe, reliable, and eventually (relatively) inexpensive rockets will make the large fixed costs of setting up a space elevator uneconomical.

planteen 10y ago
It seems like there is a wall in reliability with getting chemical rockets much more reliable than about 99% - 99.5%. SpaceX and Blue Origin are doing cool things, but I don't see them being any more reliable than previous generations of chemical rockets. If an elevator could provide more 9s of reliability, that could be huge.
- oliwaw 10y ago
  But cost is also at issue. For cargo, it might make sense to take on 0.5-1.0% risk versus the massive investments necessary for the development of a space elevator. And when we're talking about human spaceflight, consider the work SpaceX and Blue are putting into in-flight abort and propulsive landing - SpaceX's Crew Dragon should be much safer than the Space Shuttle, for example.
  - planteen 10y ago
    Yeah for cargo I agree. I was thinking more along the lines for human rating. Propulsive landing helps for some failure modes but not all. Like I don't think it would have helped the CRS-7 failure had that been manned.
    - hLHEDuYtSh 10y ago
      It actually would have helped on CRS-7 -- That capsule was fine until it hit the water. https://www.nasaspaceflight.com/2015/07/saving-spaceship-dragon-contingency-chute/ https://www.nasaspaceflight.com/2015/07/saving-spaceship-dra...
      - deleted 10y ago
        [deleted]
chriswarbo 10y ago
I think that the best long term way to spur investment in projects like a space elevator would be to make space as economically attractive as possible. In-situ resources, extracted/processed robotically and accessed via low cost rockets is the way to do that. Once we have a rocket-powered transport network between, say, Earth-orbiting space stations, a moon colony, some near-Earth asteroid mines, fuel depots at lagrange points, a Phobos outpost and robotic factories on Mars, the economic payoff of a space elevator will be more immediate. Plus we could try them out on less massive bodies first, like the moon.

astazangasta 10y ago

The issues are huge and probably insurmountable. For example: where would you site it? It has to be equatorial so it can be below the geostationary counterweight. Just the motion of the cable from the eccentricity in the earth's rotation and orbit would probably tear the cable apart (imagine what the foundation of the base station would have to be, and how it would buckle and lift as the earth rotates). The space elevator is an idea that sounds cool but is fucking dumb if you think about it for more than ten minutes, like the idea of accelerating ships to near light speed, when every hydrogen atom in the void will shred your hull like a cosmic ray.

anubisresources 10y ago

They make no sense when compared with alternate method like launch loops, which can be built with current tech

_archon_ 10y ago
80km high track supported by centrifugal force and belt momentum, and tethered by (the same type of cable necessary for a space elevator)? With a belt over 4000 km long capable of 14km/sec without flying apart or overheating? Which part of this is current tech?