Resolves as YES if a spacecraft with a nuclear engine achieves an Operational Empty Weight specific thrust power of >100 kW/kg at a specific impulse of >10,000 s prior to 2100.

"Nuclear engine" means that the engine derives it's thrust power from fission or fusion of fuel that is carried onboard the spacecraft prior to ignition - so a nuclear pulse engine, saltwater rocket, or direct fusion engine would qualify, but an thin film solar sail would not.