This is the first part of a two-paper series that reports the design, experimentation, and results of a spray quenching experiment of a circular metal disk in terrestrial gravity condition. The objective of this experiment is to provide experimental data and corresponding analysis on the heat transfer characteristics and chilldown performance of the cryogenic spray quenching process. In this paper, the presented continuous-flow spray quenching results include the spray-cone angle visualization, spray cooling heat transfer characteristics represented by chilldown curves and boiling curves, gravity effects, and Leidenfrost rewet point temperatures. Additionally, detailed discussion is given on the film boiling heat transfer and rewet temperature in terms of various contributing factors such as gravitational acceleration, spray mass flux, and radial position on the plate. Based on the experimental data, empirical correlations for film boiling heat transfer coefficient, and rewet temperatures are provided. We expect that the current terrestrial study would offer invaluable information for the design of a robust in-space cryogenic propellant storage tank spray chilldown system.