How Weather Balloons Work

Like many things in the aerospace industry, the complex mechanisms by which weather balloons operate can, at their core, be explained by very basic principles discovered by Archimedes over two and half  thousand years ago. Legend has it that Archimedes was taking a bath when he realized that floating objects displace their mass while submerged objects displace their volume. After this discovery, he allegedly ran through the streets of Athens naked, shouting “Eureka”, which in English translates as “I have found it.” This principle is what causes weather balloons to rise, their volume displaces more mass then the combined mass of the helium inside the balloon and the balloon skin itself, which produces a buoyant forces that acts on the balloon. This force continues to act on the balloon until it pops, the air around it becomes less dense, causing the gas inside the balloon to expand due to a difference in pressure. At some point, this pressure is too much for the balloon skin, and it bursts, sending the capsule plummeting back down to earth. On its way down,  aerodynamic drag caused by friction between the parachute and the shape of the capsule will slows it down enough to make a soft landing. A capsule’s time aloft can vary from a couple hours to almost half a day depending on its weight. Scientists use this time to make atmospheric measurements as well as to take stunning photographs of the upper atmosphere

A beautiful image taken by June Sky’s Gemini 1 of the cloud-tops.

Weather Balloons at June Sky

Weather Balloons have been an important element of things here at June Sky ever since the winter of 2012-2013. Reeling off setback after setback on the H2O2 project, we decided to switch our focus to High Altitude Test  weather balloons (HATs) to show the world that we were more than just talk, that we could actually accomplish something more than just making a logo and talking about creating cool things. The goals of the project were fourfold, to capture high quality images of the atmosphere, to track the altitude and speed of the balloon, reach an altitude of 80 thousand feet and mostly importantly to recover it. We eventually achieved all three of these goals, but not without months of hard work and extensive preparation. Weather balloons are still a big part of June Sky, as the group is currently working on two entries into the Global Space Balloon Challenge: an autonomous glider, and a biological experiment. You can read more about our different weather balloon capsules by clicking the pictures and text below or taking a look at our blog.

Vega 1


Gemini I




Thor Capsule