Primarily, Vulcan was intended as a high-altitude bomber capable of carrying nuclear bombs, but its role evolved over time. Thus, later served in low-level bombing and as a refueling tanker.

Browse a gallery of the U.S. Air Force's high-altitude balloon experiments and the researchers, scientists, and test pilots who made them possible.

Traveling at high altitude can be hazardous. The information provided here is designed for educational use only and is not a substitute for specific training or experience. Princeton University and ...