John has previously worked on the SpaceX Raptor engine and has presented a nuclear air-breathing rocket design. The new design is a single-stage to Orbit air-breathing rocket.

It would have a mission-average Isp of more than 1,600sec and payload fractions of 25-50%

John revisited the assumptions around rockets and will use hot hydrogen fuel to enable air-breathing hypersonic rockets to be simplified.

An air-breathing rocket can increase the payload capacity from 1-4% to 25-50%.

The rocket would run at 1000 to 1300 kelvin which does not require new materials.
There has been previous development of hot hydrogen vehicles.

It is a lighter rocket and will use air-braking and then a propulsive thrust landing. Vertical takeoff and vertical landing.