Cooling a Second Stage Rocket Engine

Motor Driver to Deploy Cryogenic Propellant

We helped a company in the space industry develop and prototype a Motor Driver Box that can control a cryogenic pump in a second-stage launch vehicle’s engine. Included in this system are a DC-DC converter and an inverter that serve to drive the engine’s fuel and oxidizer pumps to deploy cryogenic propellant (liquid oxygen and hydrogen) before second stage ignition. This prevents the rocket’s pipes from bursting due to the rapid expansion of the fluid.

The intent of the prototype was to validate the efficiency and performance of the high-risk elements in the operational environment.

The prototype included a Boost Converter board, an Inverter & Phase Disconnect board, and an EMI board that was used as a backplane to support integrated testing at that stage. Firmware for the prototype was developed on a Motor Controller Unit (MCU) to expedite development, with the expectation that the client would implement an FPGA in a later phase. All hardware was designed to be form, fit, and function for flight and pass radiation and high-risk environmental testing, with the intent of passing QTP (Qualification Test Procedure).

System Diagram of SOE’s DC-DC Converter and Inverter