Google Loon project balloons are equipped with ADS-B. This is more a question for the satellite guys.
Satellites don't have/need mode-s transponders. Interestingly there *are* satellites with ADS-B *receivers* on them for global aircraft tracking. It's very much like what we're doing only each receiver has waaaaaaaaaaaaaay more range than ours do!
I was aware of the situation when they are in orbit, but the first and second stages, are transponders required, and where registered?
Rocket stages aren't aircraft so I really don't think they need ADS-B transponders. They do have telemetry transmitters on them but it's all custom stuff.
Kind of an old thread but here goes: Satellites are easy to track because once they are in orbit they mostly coast so their positions are kept track of by knowing their orbital parameters and knowing the current time. Various organizations maintain satellite databases that get updated frequently. You can download this data and as long as the data is fresh (like within 4-5 days) you can be off the net and predict Satellite orbits. Marlin
Actually space based receivers have about as much range as ours do. There are 2 main differences 1) is the height above ground gives them a larger horizon. For example the ISS orbits at a fairly low altitude between 403 and 406 km (250-252 miles) can see a good chunk, but towards the edges resolution would be poor. 2) they have mostly nothing between them and the plane over that distance, while we have wet atmosphere. The upside for us is that ADSB usually isn't transmitted much up, and more out and down. however that "nothing in the way" really helps reception.
