I’ve been reading some of the past columns and found a few references to weather balloons, and I got to thinking about their limits. How high can a balloon go into the atmosphere? Presumably, if the balloon itself can hold up under the conditions, it would eventually hit a “ceiling.” Has there ever been any determination as to how high that ceiling is? What happens to balloons in the process of getting there (and after they get there), and what kind of preparation is necessary for them to make it?
Balloon telescopes run at around 120,000 feet.
The photo in the above link shows the telescope balloon fully infated on the ground, ready for flight. By the time it reaches 120,000 feet the gas inside the balloon will have expanded to make the craft nearly spherical.