Developed a MATLAB-based mass flow calculator for the LOx pump system within the PURPL-Purdue/Turbopump repository, focusing on precise modeling of liquid nitrogen requirements based on thermodynamic principles. The solution was implemented as a standalone, well-documented script that computes mass flow using specific heat and temperature change calculations, supporting engineering and mathematics-driven design decisions. This utility enables more accurate system optimization and accelerates design iteration by providing a testable, ready-to-review artifact. The work demonstrated a methodical approach to problem-solving in thermodynamics and programming, delivering a focused feature that enhances the modeling fidelity of the LOx pump subsystem without introducing bug fixes.