[throw0101a]

The return link seems to be part of the EU's Galileo GNSS system, which has SAR components to it generally, and this is a new one:

* https://www.euspa.europa.eu/newsroom/news/galileo-return-lin...

Galileo's implementation actually seems to have entered "full operational capacity" a few months ago:

* https://ec.europa.eu/defence-industry-space/galileosar-uniqu...

The US has officially approved use of the appropriate spectrum (406 MHz) as well:

* https://www.federalregister.gov/documents/2021/02/08/2021-02...