The Experiment for X-ray Characterization and Timing (EXACT) mission is a 3U CubeSat technology-development project being built by the SmallSat team at the University of MN – Twin Cities which is a joint research effort of the Aerospace Engineering and Mechanics (AEM) Department and the School of Physics and Astronomy (SPA). The main objective of this spacecraft is to carry a payload including a detector designed to measure energy and time of arrival time of individual hard x-ray photons emitted from the Sun and from other astrophysical sources. During the development process for EXACT, flights provided by the High-Altitude Student Platform (HASP) program run by Louisiana State University and NASA’s Balloon Program Office have allowed testing of payload components for multiple-hour-duration missions in near-space conditions on a high-altitude balloon platform. Conditions in near-space reachable by helium-filled balloons share many similarities with the outer space environment, so high-altitude balloon missions are becoming a popular form of CubeSat testing. Both frequent local weather ballooning and annual HASP flights have provided useful opportunities for experimentation, development, and testing for the EXACT project as well as fostering collaboration between research efforts in the two aforementioned departments, senior design projects, and the MN Space Grant’s stratospheric ballooning team at the U of MN – Twin Cities. Cooperation between the SmallSat team and the other groups has been crucial for the progress to date of the EXACT project