I’d like to address the partial myth that reusing latex weather balloons isn’t possible. Latex balloons are not normally reused, but they can be in certain limited situations.
I believe this myth comes from the fact that most amateur flights simply ascend until the weather balloon bursts. This provides a convenient and reliable termination method and helps to ensure that the payload remains close to the launch site. But there are many reasons why longer duration flights may be desirable. Some examples are: extended time at altitude, drifting with an air mass, or reducing the payload motion.
I’ve successfully reused latex balloons on 3 different low-altitude flights. I vented just enough lift gas for a slow descent once the balloon was over an area where it was possible to grab it. Then waited for it to come down. It is not even necessary to immediately catch the balloon in calm conditions. Once part of the payload touches the ground the balloon will stop descending.
Why reuse the balloon?
The main benefit of recovering and reusing the latex balloon in these instances was that all of the lift gas is not lost between flights. Only the small amount of lift gas vented for altitude control was lost. A small additional amount of lift gas had to be added before relaunching the balloon to provide the free-lift necessary to get back up to the desired altitude.
Being able to reuse a latex balloon in this manor will require calm conditions, controlled venting capability, and a need for quick-succession flights. Latex weather balloon envelopes are more resilient than most people think. Most human caused ruptures I’ve witnessed are from a forgotten watch or ring on a finger puncturing the envelope. I would also suggest only trying this with light payloads (<10 lbs) as ground personal safety is an issue.
For certain flight cases catching and relaunching a free-floating latex balloon can be a useful technique. For instance, I successfully used this technique on flights for R&D, acoustic bird surveys, and low-altitude icing studies.
I would be interested to hear about other people’s experience with reusing latex weather balloons!