Technically, the internet as a whole is a mesh network. As are any of the independent communications systems composed of many relays like man made satellite systems, Starlink, etc.

I am positive that many many entities and probably every country and any big enough organization has their own private mesh networks for circumventing any of the “Big Brothers” and especially the Five Eyes. Just a basic matter of security rather than solely relying on encryption algorithms which we know are actively being circumvented by organizations such as the NSA, GCHQ, intel orgs all over, using computing technologies probably far beyond anything available to the public.

I would not be surprised AT ALL if part of the entire point of Space Force is to map and intercept communications within these private mesh networks. :)