2 ms·

Also speaking very hypothetically, why do you suppose that all the input electrical power is wasted for the propulsion goal? Each fusion mini-explosion will hav

Also speaking very hypothetically, why do you suppose that all the input electrical power is wasted for the propulsion goal? Each fusion mini-explosion will have a total energy that is the sum of the input (ignition) energy and the fusion itself, not just that of the fusion. Edit: This would mean that the thrust could be higher than the electrical input power even below break-even for the controlled fusion. If you only consider the electrical input, you could have a >1 ratio for the electrical energy/kinetic energy conversion (thanks to the fusion).

lutusp 14y ago
> Also speaking very hypothetically, why do you suppose that all the input electrical power is wasted for the propulsion goal? Each fusion mini-explosion will have a total energy that is the sum of the input (ignition) energy and the fusion itself, not just that of the fusion. Yes, technically true, but consider this hypothetical scenario: 1. A power source, let's say 1000 watts, can be used for any purpose, or can be used to heat a fusion plasma. 2. A fusion reactor requires 1000 watts to sustain fusion but delivers 250 watts of fusion power. 3. The total power in the system is now 1,250 watts. 4. But that total power is not available for external uses. 1000 watts of it must perpetually be applied only to the task of heating the plasma. 5. That leaves 250 watts for other uses. That means the fusion reaction uses more power than it produces, only 250 watts is available for other purposes, and there is no remedy except to not use the fusion reactor. That's why break-even is an essential precondition for this project's viability.