Actually dragging (or wheeling in) a wire or having a wire car supplying the plane with electricity during takeoff would work too.
After doing more of the math, I realized that the energetic cost of takeoff is quite a small fraction of the overall cost. So the only real benefit of the catapult would be to reduce the size and weight of the propulsive machinery on the plane. So externally providing just the electricity wouldn’t be much of a benefit.
This is a pretty bananas idea, but I wondered if in the future we’ll be able to have something like a large robot arm “throw” a small plane from the top of a skyscraper as well as catch it for landing. Something like a modified trebuchet, slowly storing energy in a suspended weight to power throwing the plane, or to store the energy from catching the plane. We’d probably need further advances in robotics control, and the arm might need to be too heavy to be fast enough. And overall this makes even less sense than a catapult / puller that is already in use for gliders.
After doing more of the math, I realized that the energetic cost of takeoff is quite a small fraction of the overall cost. So the only real benefit of the catapult would be to reduce the size and weight of the propulsive machinery on the plane. So externally providing just the electricity wouldn’t be much of a benefit.
This is a pretty bananas idea, but I wondered if in the future we’ll be able to have something like a large robot arm “throw” a small plane from the top of a skyscraper as well as catch it for landing. Something like a modified trebuchet, slowly storing energy in a suspended weight to power throwing the plane, or to store the energy from catching the plane. We’d probably need further advances in robotics control, and the arm might need to be too heavy to be fast enough. And overall this makes even less sense than a catapult / puller that is already in use for gliders.