Design and analysis of a single stage to orbit nuclear thermal rocket reactor engine - ScienceDirect

Single-stage-to-orbit - Wikipedia

Can nuclear thermal propulsion power a single stage to orbit a spacecraft? - Quora

Figure 1 from The Nuclear Thermal Propulsion Stage (NTPS): A Key Space Asset for Human Exploration and Commercial Missions to the Moon

NASA Reignites Program for Nuclear Thermal Rockets - Universe Today

ToughSF: NTER: Nuclear Thermal-Electric Rocket

Can nuclear thermal propulsion power a single stage to orbit a spacecraft? - Quora

Design and analysis of a single stage to orbit nuclear thermal rocket reactor engine - ScienceDirect

Timber Wind: America's Return to Nuclear Thermal Rockets – Beyond NERVA

Initial risk assessment for a single stage to orbit nuclear thermal rocket - ScienceDirect

Gaseous core nuclear design, the Liberty Ship

Why Do Rockets Need Stages? The Quest to Build a Single Stage to Orbit (SSTO) - Universe Today