6 ms·

But also, we don't have the technology to do that, either.

lmilcin 6y ago
Sure we have. We have rockets to get there and we have nuclear reactors to vaporize stuff. Asteroid itself can be used as reaction mass. The amounts of energy can be as little as you want if you go far from the sun where orbits are very slow and very little energy needs to be used to move an asteroid in any direction you want.
- manderley 6y ago
  This is pure sci-fi. We don't have the technology to travel within our solar system in any reasonable amount of time, let alone to bring back and mine an asteroid.
  - lmilcin 6y ago
    Again, that is simply not true. The technology already exists. Need a modest rocket that can bring a nuclear reactor to an asteroid and heat up part of its mass as exhaust for a long enough time to deflect it by couple cm/s to maybe 1 m/s. The only thing you need to do is to be patient. A lot depends on how greedy you are, if you want a smaller one it gets exponentially easier. Just read this 10 year old report: https://space.nss.org/technologies-for-asteroid-capture-into-earth-orbit/ https://space.nss.org/technologies-for-asteroid-capture-into...
    - jessaustin 6y ago
      Did you read the "Note" at the top of that link? From that it's clear that this is a many-decade project: if it had been started in 2011, it would only be partially done by 2030. That would not be the "reasonable amount of time" requested by parent. Technology will improve, and eventually all sorts of things will be feasible. More reasonable plans can be hatched at that time.
      - lmilcin 6y ago
        There is huge difference between multi-decade projects and "pure sci-fi" or "impossible". "Reasonable" is subjective to define, but there are many multi-decade projects running right now so I don't think of multi-decade projects as unreasonable. Things like sending man to the Moon or building Space Station would have been deemed "pure sci-fi" with the approach of the parent commenter.
  - Teever 6y ago
    People said the same thing about reusable rockets only a decade ago. Now they're common place. All the things above are fully realizable in the coming decades, they are not in the realm of science fiction what so ever they are merely engineering problems.
  - adolph 6y ago
    1. Define “reasonable amount of time” 2. Define “technology” The meta-technology of R&D and socio-economic programs that will make these things happen exists and gets better every day. If a method to perform the needful does not exist, it will given the right conditions.
- blackrock 6y ago
  How exactly would you use a nuclear reactor in space to melt stuff? I assume it would be indirectly right? On earth, the nuclear reactors are radioactive rods that heats up water, to create steam, to spin a turbine, to create electricity. This is like a 5 stage process to indirectly generate electricity. But all the intermediary products are now radioactive. So in space, I assume you can use the same steps to generate electricity, and then use the electricity to run a furnace, to heat up the minerals to melt it into pure metals. Or is there some other process of using the nuclear radiation directly in space?
  - lmilcin 6y ago
    On Earth, nuclear reactors are complicated because they must be safe. But really, reactors are extremely simple. For example, on Voyager missions the it is just a hunk of metal that is constantly hot. https://en.wikipedia.org/wiki/MHW-RTG https://en.wikipedia.org/wiki/MHW-RTG You then do with that energy whatever you want. You can use part of it to power electronics and actuators, part to melt a piece of asteroid and part of it to convert it to ions and send whichever way you want.
    - perl4ever 6y ago
      An RTG is not the same sort of thing as a regular fission power plant. I don't believe they are efficient or high powered - they are just useful as batteries that last a long time without maintenance or recharging. Also, RTGs have been used on earth, contrary to your implication they are only in space for safety reasons. Russian equipment in the arctic, for instance, has been powered by RTGs.
      - lmilcin 6y ago
        You missed the point of the comment. The point is you don't need huge complicated nuclear reactor to produce practically endless supply of energy in space, which is what the parent said he thought is a problem. You probably need more energy than RTG but probably not as much as most people think. If you can apply a steady force for years, you would be able to give the required 10-100cm/s velocity delta to even large asteroid.

Sure we have. We have rockets to get there and we have nuclear reactors to vaporize stuff. Asteroid itself can be used as reaction mass. The amounts of energy can be as little as you want if you go far from the sun where orbits are very slow and very little energy needs to be used to move an asteroid in any direction you want.

manderley 6y ago
This is pure sci-fi. We don't have the technology to travel within our solar system in any reasonable amount of time, let alone to bring back and mine an asteroid.
- lmilcin 6y ago
  Again, that is simply not true. The technology already exists. Need a modest rocket that can bring a nuclear reactor to an asteroid and heat up part of its mass as exhaust for a long enough time to deflect it by couple cm/s to maybe 1 m/s. The only thing you need to do is to be patient. A lot depends on how greedy you are, if you want a smaller one it gets exponentially easier. Just read this 10 year old report: https://space.nss.org/technologies-for-asteroid-capture-into-earth-orbit/ https://space.nss.org/technologies-for-asteroid-capture-into...
  - jessaustin 6y ago
    Did you read the "Note" at the top of that link? From that it's clear that this is a many-decade project: if it had been started in 2011, it would only be partially done by 2030. That would not be the "reasonable amount of time" requested by parent. Technology will improve, and eventually all sorts of things will be feasible. More reasonable plans can be hatched at that time.
    - lmilcin 6y ago
      There is huge difference between multi-decade projects and "pure sci-fi" or "impossible". "Reasonable" is subjective to define, but there are many multi-decade projects running right now so I don't think of multi-decade projects as unreasonable. Things like sending man to the Moon or building Space Station would have been deemed "pure sci-fi" with the approach of the parent commenter.
- Teever 6y ago
  People said the same thing about reusable rockets only a decade ago. Now they're common place. All the things above are fully realizable in the coming decades, they are not in the realm of science fiction what so ever they are merely engineering problems.
- adolph 6y ago
  1. Define “reasonable amount of time” 2. Define “technology” The meta-technology of R&D and socio-economic programs that will make these things happen exists and gets better every day. If a method to perform the needful does not exist, it will given the right conditions.
blackrock 6y ago
How exactly would you use a nuclear reactor in space to melt stuff? I assume it would be indirectly right? On earth, the nuclear reactors are radioactive rods that heats up water, to create steam, to spin a turbine, to create electricity. This is like a 5 stage process to indirectly generate electricity. But all the intermediary products are now radioactive. So in space, I assume you can use the same steps to generate electricity, and then use the electricity to run a furnace, to heat up the minerals to melt it into pure metals. Or is there some other process of using the nuclear radiation directly in space?
- lmilcin 6y ago
  On Earth, nuclear reactors are complicated because they must be safe. But really, reactors are extremely simple. For example, on Voyager missions the it is just a hunk of metal that is constantly hot. https://en.wikipedia.org/wiki/MHW-RTG https://en.wikipedia.org/wiki/MHW-RTG You then do with that energy whatever you want. You can use part of it to power electronics and actuators, part to melt a piece of asteroid and part of it to convert it to ions and send whichever way you want.
  - perl4ever 6y ago
    An RTG is not the same sort of thing as a regular fission power plant. I don't believe they are efficient or high powered - they are just useful as batteries that last a long time without maintenance or recharging. Also, RTGs have been used on earth, contrary to your implication they are only in space for safety reasons. Russian equipment in the arctic, for instance, has been powered by RTGs.
    - lmilcin 6y ago
      You missed the point of the comment. The point is you don't need huge complicated nuclear reactor to produce practically endless supply of energy in space, which is what the parent said he thought is a problem. You probably need more energy than RTG but probably not as much as most people think. If you can apply a steady force for years, you would be able to give the required 10-100cm/s velocity delta to even large asteroid.