Introduction to Weather Balloons

Weather balloons are a type of high altitude balloon specifically used for transporting scientific payloads into our upper atmosphere. They can carry their payloads as high as 40,000 m ~ 130,000 ft. Every day approximately 800 meteorological weather balloons are released at 00:00 and again at 12:00 GMT at locations around the world. This provides a “snapshot” of our earth’s upper atmosphere twice a day. The few launches done by amateurs every day are just a drop in the bucket compared to the 1,600 or so launches done by meteorological organizations around the world.

History

One of the earliest documented uses of weather balloons was by French meteorologist Leon Teisserenc de Bort. He was actively launching weather balloons as early as 1896. His work was instrumental in the discovery of the tropopause and stratosphere. These are unique layers in our atmosphere which you can discover for yourself with the Eagle Flight Computer. James Van Allen, who would later discover our Earth’s Van Allen Belts, also performed many important weather balloon experiments in the 1950’s.

Manufacturing Process

Weather balloons are typically manufactured from latex or Chloroprene (more commonly known as Neoprene). Latex is a natural substance found in many plants (not to be confused with sap). Plants use latex as a defense against herbivorous insects. This milk like liquid can be extracted from trees much like maple syrup is extracted from maple trees. Once the latex is naturally extracted or the Neoprene is chemically produced, it is spun in a mold in the shape of the balloon and cured.

Many high altitude balloonists prefer using latex balloons as they are more environmentally friendly than Neoprene balloons. Sometimes a bleach is added to latex to give it a whiter appearance. This is unnecessary and makes the balloon less environmentally friendly. Latex balloons with no bleach additive have a slightly brown color which is more noticeable at their neck where the balloon membrane is thickest.

  

Different Sizes

Weather balloons are listed by weight in grams and not by physical size. Websites that advertise the “bursting diameter” of a balloon are simply trying to take advantage of potential customers with little or no experience launching balloons. There are many factors that affect “bursting diameter,” including pressure, temperature, manufacturing process, humidity, etc.

Why does the actual weight of a balloon matter? A balloon will slowly expand as it climbs higher into our atmosphere. The heavier the balloon, the larger it can expand before bursting, thus a 1200 g balloon is capable of climbing higher into our atmosphere with a given payload before bursting than a 600 g balloon.

What Size is Right for Me?

Heavier balloons typically have a larger uninflated envelope size  and are harder to inflate. If you don’t have much experience inflating weather balloons, we recommend starting with a 600g weather balloon. A 600 g balloon is still capable of taking our Eagle to an altitude of over 27,000 m ~ 90,000 ft. If you want to fly a heavier payload or wish to get your Eagle over 30,000 m ~ 110,000 ft, we recommend using our 1,200g weather balloon.

Balloon Neck

The diameter of the balloon's neck is an important consideration. The greater the diameter of the neck, the more surface area there is between the inflation nozzle and the neck. Extra surface area increases friction and drastically reduces the chance of your balloon slipping off its inflation nozzle during the inflation process and floating off. Just make sure you use the right size inflation nozzle. Having a balloon with a larger diameter neck won't help you unless you use a larger diameter inflation nozzle.

 



 Lifting Gas

Common lighter-than-air gasses used for inflating high altitude balloons are helium and hydrogen. Hydrogen is easy to manufacture and is thus cheaper than helium, but it is far more dangerous to work with. Helium is a byproduct of the radioactive decay of uranium and there are no practical known ways of manufacturing helium… short of creating your own miniature sun. Luckily for us, our earth has large reserves of helium in the North American natural gas fields.

We would never recommend that any of our customers ever use hydrogen as their lifting gas. It is an extremely dangerous gas to work with without proper training. Think Hindenburg. Zeppelin never designed the Hindenburg to be flown with hydrogen as its lifting gas. It was only after he went before Congress and they refused the export of helium to Germany that he used hydrogen.