A "House of Cards" is a wonderful English phrase that it seems is now primarily associated with a Netflix political drama. However, its original meaning is of a system that is fundamentally unstable. It's also the term Sarah Thiele, originally a Ph.D. student at the University of British Columbia, and now at Princeton, and her co-authors used to describe our current satellite mega-constellation system in a new paper available in pre-print on arXiv.
It’s pretty hard without state-level resources. A balloon can go abou 60km up. LEO begins like 400km IIRC.
LEO begins at around 160km. The ISS is between 400 and 420km at any given moment
Thank you, I stand corrected.