Hacker News Reader

Comment by ggreer | Hacker News Reader

The FCC requires that airborne transmitters identify themselves by broadcasting the an FAA designator such as the aircraft registration number.[1] The FAA has no identification or registration process for small weather balloons. So this effectively prohibits them from broadcasting. It's possible to add a radar reflector, but they add significant weight and bulk to the balloon's payload. I think reflectors are only required for larger weather balloons.

1. See § 87.107: https://www.govinfo.gov/content/pkg/CFR-2024-title47-vol5/pd...

View on HN

I'm confused about where the prohibition is. N991SS is an example of an FAA aircraft registration number for a balloon; I looked it up myself on the FAA N-number inquiry site to confirm. Your link does not talk about balloons at all. Where does the FAA prohibit weather balloons here? It sounds like it's just physically not possible to carry a transponder or reflector on a small weather balloon? But that's different than what the earlier posts were suggesting. It seems like it's physics preventing ADS-B on small balloons, not the FAA. If you did manage to get ADS-B on your balloon somehow, could you not register the balloon like the owners of N991SS did?

That balloon has a payload of up to 55lbs, so it follows different rules. WindBorne balloons are 1.1kg including the initial ballast.

There are ADS-B transmitters that weigh 50 grams and would require 60 grams of batteries to power them for 8 hours, so payload limitations are not an issue for WindBorne.[1]

The CEO of WindBorne replied to a comment about the inability to use ADS-B on weather balloons saying, "Yea, the FAA does a lot and I think overall they do a great job, but I wish there was better systems for communications here."[2] So I'm reasonably confident that my understanding is correct.

1. https://news.ycombinator.com/item?id=45660400

2. https://news.ycombinator.com/item?id=45660577

Sorry to drive by, but weather balloons like Windborne produces are deployed for a lot longer than eight hours. Many are up for more than two weeks, some even exceeding a month.

Reply on news.ycombinator.com