3 ms·
According to https://www.etec.energy.gov/Operations/Major_Operations/MajorOpsImages/SNAP_10A_Thermodynamic_cycle.jpg https://www.etec.energy.gov/Operations/Majo
by mumblemumble 5y ago
According to https://www.etec.energy.gov/Operations/Major_Operations/MajorOpsImages/SNAP_10A_Thermodynamic_cycle.jpg https://www.etec.energy.gov/Operations/Major_Operations/Majo... it's even worse than that; 1.83%.
That said, it seems like, all by itself, conversion efficiency is a tricky measure of the usefulness of a design for spaceflight purposes. Wouldn't it be more useful to consider the total cost to deliver a given energy production capacity to space? In that case, rocket fuel itself, and the tyranny of the rocket equation, becomes a major consideration. If an efficiency gain comes at the cost of increasing the weight of the energy generation system in some way, then perhaps it doesn't end up being a net win over the less efficient design.
- Retric 5y agoEfficiency is a big deal in part because you need to radiate out all that thermal energy. A radiator that’s dumping 100kw of thermal energy for 1.3kw of electricity is much heavier than a 1.3kw solar panel anywhere near earth. Add 50kg for fuel and and things look even worse. By comparison the voyager probe RTG used ~1/10th the fuel for a little over 1/10th the power. https://en.wikipedia.org/wiki/MHW-RTG https://en.wikipedia.org/wiki/MHW-RTG So the only advantage was cheaper fuel.