I believe you're referring to https://en.wikipedia.org/wiki/Orion_(satellite)
> The satellites have estimated mass close to 5,200 kg and very large (estimated 100 m diameter)[2] radio reflecting dishes. USA-223 (NROL-32), which is seen as the fifth satellite in the series, is according to NRO director Bruce Carlson "the largest satellite in the world".[3] It is believed that this refers to the diameter of the main antenna, which might be well in excess of 100 m (330 ft).[4]
I've never bothered following the citations so I don't know how true this is, but it's pretty insane if it's real. A 100-meter-diameter satellite! I know it's an unfolding-umbrella-style mesh like you said, but still, that's impressive.
Re:Your Cellphone Will Be a Satphone
by walrus01 on Wednesday December 28, 2022 @04:29AM
(#34159156)
The giant unfolding umbrella antenna is not far off from what has been thoroughly commercially publicized for the unclassified commercial first and second gen Thuraya satellites (Boeing 702 bus).
Trevor Paglen has a pretty amazing talk that discusses finding and photographing one of these satellites. I've linked the specific part of the talk where he starts getting into this, but the entire talk is worth a watch.
Same size satellite bus as the largest class of things you would see in geostationary orbit (approx 6500 kg and the size of a school bus) but in high inclination orbits around 600 km.