ISRO's role in delivering cost-effective launch solutions has been known worldwide for quite some time. The LVM3 launch vehicle recently injected multiple satellites into a low earth orbit using its terminal cryogenic stage. The cryogenic stage was reconfigured for the short-duration orbital mission with a short mission planning and stage realization time and it was decided to use residual propellant for mission execution. The need of the hour was a brisk yet effective modeling strategy to determine the fluid motion in the cryogenic propellant tank, its effect on the tank pressure, evaporation of liquid, and loss of propellant due to venting under microgravity conditions. This study highlights a hybrid finite difference/lumped parameter thermal model developed in SINDA/FLUINT which maps the interface and wetted area changes from a 3D CFD model and simulates heat and mass transfer interactions in the cryogenic tank. Post-flight simulations indicated that the model predicts the tank pressure and liquid evaporation with reasonable accuracy and has provided vital information for further shortduration orbital mission studies.