Launch and Propulsion

Tsiolkovsky’s equation, staging, and the mass fractions that decide whether a vehicle closes.

Propellant combinations, their performance, and the practical constraints behind each choice.

Gas generator, staged combustion, expander and pressure-fed cycles, and what each one buys.

The converging-diverging nozzle, expansion ratio, and altitude compensation.

Ion engines, the power-limited regime, and why high specific impulse changes mission design.

The workhorse of commercial electric propulsion: how it works and where it is used.

Thermal and electric nuclear systems, their promise, and the constraints that have kept them grounded.

Propulsive landing, recovery and refurbishment, and the economics that decide whether reuse pays.

The operational fleet, its performance, and how a vehicle is matched to a payload.

Air launch, rotary launch, mass drivers and tethers, assessed against the physics.