Once the payloads were finished, it was time to fly. We gathered early on the morning of launch day and headed to the university’s ballooning facility out by the Laramie airport. The weather, which is always a concern on launch day, was gorgeous! Temperatures were in the 60s and the wind—the balloon’s ultimate enemy—was quite gentle at less than 10 mph. Perfect launch conditions!
After setting up our equipment and discussing launch procedures, we began inflating our balloon. We used a 1200-g balloon, which has a burst diameter of about 30 feet. Based on our pre-flight calculations, we estimated that the balloon should be able to carry our 11-lb payload assembly to an altitude of about 90,000 feet above sea level, if not higher.