3 ms·

You could run the mass driver in reverse for landing, but you'd have to aim well.

by tveita 9y ago

adrianN 9y ago
That would be an amazing feat with the risk of destroying an extremely expensive piece of equipment.
- stcredzero 9y ago
  Is it any more amazing than doing an orbital rendezvous?
  - adrianN 9y ago
    You brake before getting close to whatever you want to rendevous with. You couldn't brake if you wanted to hit the nozzle of your mass driver to use it for braking.
    - stcredzero 9y ago
      You brake before getting close to whatever you want to rendevous with. This makes me question whether you actually understand how orbital rendezvous works. How about as an exercise, you explain why I would say this. Otherwise, I think the resulting conversation would be tiresome and not worth my time.
      - adrianN 9y ago
        How about you, just as an exercise, compare the difference in velocities of the mass driver and the incoming space craft with the difference of velocities of a capsule docking at the ISS.
        stcredzero 9y ago
        Ok, you clearly don't understand enough to understand what you don't understand. You don't have to make the velocities or the positions of specific points on the mass driver and the orbit coincide. All you have to do is to make an orbital path coincide with a great circle pathway on the moon. We can already guide spacecraft with this degree of precision. Anyone suggesting that you'd need to make specific point on the mass driver coincide in position and velocity -- that you'd need to brake first -- just doesn't understand what the discussed device is for in the first place. Basically you've just "proved" that you can't land airplanes, because they come in too fast to brake the same 1/10th of a second they touch the tarmac. o_O If you can't explain my analogy, then I'm just going to conclude you're trolling based on my previously stated disdain for DK syndrome.
      - SAI_Peregrinus 9y ago
        The relative speed of two objects docking in orbit is very small. You brake or accelerate as you get close to matching orbits. The relative speed of a capsule and the mass driver will be very high IF you're using the mass driver to slow down substantially. That's in the definition, you're using it to slow down so the initial relative speed at contact must be high. The higher the speed the less energy you have to waste lowering your orbit (slowing down beforehand). If you're slowing down beforehand enough that your relative speed of contact is low then you don't need the mass driver to brake.
ChuckMcM 9y ago
That would be rather difficult :-) I wonder sometimes however if you've ever dropped a magnet down a conductive pipe you see how the eddy currents prevent it from falling through. If you had series of conductive rings that were of a large diameter and you had electromagnets on the outside of your cargo container could you make a landing pad that primarily used the eddy currents to slow you to landing velocity? That would be a fun problem to give the physics class.

You could run the mass driver in reverse for landing, but you'd have to aim well.

by tveita 9y ago

You could run the mass driver in reverse for landing, but you'd have to aim well.

adrianN 9y ago

That would be an amazing feat with the risk of destroying an extremely expensive piece of equipment.

stcredzero 9y ago
Is it any more amazing than doing an orbital rendezvous?
- adrianN 9y ago
  You brake before getting close to whatever you want to rendevous with. You couldn't brake if you wanted to hit the nozzle of your mass driver to use it for braking.
  - stcredzero 9y ago
    You brake before getting close to whatever you want to rendevous with. This makes me question whether you actually understand how orbital rendezvous works. How about as an exercise, you explain why I would say this. Otherwise, I think the resulting conversation would be tiresome and not worth my time.
    - adrianN 9y ago
      How about you, just as an exercise, compare the difference in velocities of the mass driver and the incoming space craft with the difference of velocities of a capsule docking at the ISS.
      - stcredzero 9y ago
        Ok, you clearly don't understand enough to understand what you don't understand. You don't have to make the velocities or the positions of specific points on the mass driver and the orbit coincide. All you have to do is to make an orbital path coincide with a great circle pathway on the moon. We can already guide spacecraft with this degree of precision. Anyone suggesting that you'd need to make specific point on the mass driver coincide in position and velocity -- that you'd need to brake first -- just doesn't understand what the discussed device is for in the first place. Basically you've just "proved" that you can't land airplanes, because they come in too fast to brake the same 1/10th of a second they touch the tarmac. o_O If you can't explain my analogy, then I'm just going to conclude you're trolling based on my previously stated disdain for DK syndrome.
    - SAI_Peregrinus 9y ago
      The relative speed of two objects docking in orbit is very small. You brake or accelerate as you get close to matching orbits. The relative speed of a capsule and the mass driver will be very high IF you're using the mass driver to slow down substantially. That's in the definition, you're using it to slow down so the initial relative speed at contact must be high. The higher the speed the less energy you have to waste lowering your orbit (slowing down beforehand). If you're slowing down beforehand enough that your relative speed of contact is low then you don't need the mass driver to brake.

ChuckMcM 9y ago

That would be rather difficult :-) I wonder sometimes however if you've ever dropped a magnet down a conductive pipe you see how the eddy currents prevent it from falling through. If you had series of conductive rings that were of a large diameter and you had electromagnets on the outside of your cargo container could you make a landing pad that primarily used the eddy currents to slow you to landing velocity? That would be a fun problem to give the physics class.