Tunable diode laser absorption spectroscopy (TDLAS) and more specifically, wavelength modulation spectroscopy is used in the course of this work as a non-intrusive in-situ diagnostic method for determination of oxygen concentration and local temperatures of a laminar diffusion flame over a solid fuel (PMMA) under microgravity. With the information gathered regarding the species' concentration at a given time step and location, the burning rate of the flame can be characterized.
