Comment by tndl

What's the project? Maybe we can help!

> Can I ask how you handled the regulatory aspect of launching from urban areas in SF? I can imagine the FAA would have given you some trouble?

We actually fall under a weather balloon exemption to the normal FAA rules for unmanned balloon flights. Here’s a quick rundown of the relevant rules and regulations (Part 101.1) for weather balloon flights in the U.S. Our balloons fully comply with all of these:

- Any on-board cellular tracking devices must be set to Airplane mode before takeoff (we don't have any cellular) - Each individual payload box/package must weigh less than 6 pounds (ours is <250g)

- If a payload has a weight-to-size ratio exceeding 3.0 ounces per square inch, it must weigh less than 4 pounds.

  - Calculation: Divide the total payload weight in ounces by the area of its smallest face in square inches.

- If multiple payloads are carried by a single balloon, their combined weight must be under 12 pounds.

- The string connecting the payload to the balloon must break under an impact force of no more than 50 pounds (our string is 30g)

- It’s prohibited to design or operate an unmanned free balloon in a way that poses a hazard to people or property.

- Dropping objects from the balloon that could endanger people or property is not allowed.

We don't have to notify the FAA about our operations as long as we meet these criteria. To be super safe, we don't launch near airports or other busy areas.