Physics of an Exploding Space Weather Balloon

by Dr. Tony Phillips (Spaceweather.com)

On Feb. 27, 2016, the students of Earth to Sky Calculus launched a space weather balloon to measure increasing levels of cosmic rays. At the apex of the flight, the balloon exploded as planned and the radiation sensors parachuted back to Earth. A high-speed camera on top of the payload captured some extraordinary images of the pop:

These images illustrate new findings about the physics of exploding balloons. In Oct. 2015, researchers SĂ©bastien Moulinet and Mokhtar Adda-Bedia of the Ecole Normale SupĂ©rieure published a Physical Review Letter entitled “Popping Balloons: A Case Study of Dynamical Fragmentation.” In it, they reported the results of a series of fun yet informative laboratory experiments in which one balloon after another was popped and analyzed.

Basically, there are two ways a balloon can pop: along a single tear (the “opening regime”) or along many tears (the “fragmentation regime”). This video shows the two regimes in action. Which way the balloon decided to pop depends on the stress in the rubber membrane. When the stress is low, it can be relieved with a single tear, but when the stress is high, many tears are required to do the job.

Clearly, space weather balloons explode in the fragmentation regime. This is hardly a surprise. When space weather balloons are launched, they measure no more than 6 to 8 feet in diameter. By the time they reach the stratosphere, they have stretched into a sphere as wide as a house. That’s a lot of tension to release!

More information about this research is available from the American Physical Society.