Here's the Tweet by the author of the blog post that kicks off an interesting Twitter thread:
New blog post: Anatomy of @Blockstream Satellite. Motivated by a GRCon22 CTF challenge, here I look at the details of how Blockstream Satellite's protocol stack works. It's based on DVB-S2, MPE, and some custom UDP multicast packets. https://destevez.net/2022/10/anatomy-of-blockstream-satellite