In rocket engines and gas turbine engines, a gas generator is a small combustion chamber used to produce a steady stream of hot, high-pressure gas. Instead of producing thrust directly, this gas is routed to spin a turbine, which in turn drives the main fuel and oxidizer pumps. It acts as the power plant for the engine's internal plumbing, ensuring massive amounts of propellant are fed into the main combustion chamber.
We saw a pressure drop in the gas generator right before the turbopump stalled.
Related terms
Preburner
A small combustion chamber in a staged-combustion rocket engine used to drive the turbopumps.
Turbojet
An airbreathing jet engine that generates all its forward thrust directly from high-velocity exhaust gas.
Sustainer
A rocket engine designed to burn continuously from liftoff through the later stages of ascent.