Now look at the power density (and power/$) of rocket engines.
A Falcon 9's Merlin 1D engine is reported to cost $400K. Its jet kinetic power in vacuum is 1.5 GW, in an engine with a mass of ~500 kg.
$0.27/kW is insanely cheap for a heat engine.
A Falcon 9's Merlin 1D engine is reported to cost $400K. Its jet kinetic power in vacuum is 1.5 GW, in an engine with a mass of ~500 kg.
$0.27/kW is insanely cheap for a heat engine.
There are likely some compromises engineers can make when the engine is only running for that amount of time with refurbishment in between each 6 minute runtime.