Who discovered satellite virus?

Kassanis discovered satellite virus.
Satellite tobacco necrosis virus (STNV) was the first satellite virus to be recognized, the term “satellite virus” being coined to denote the 18 nm isometric particles associated with the 28 nm TNV isometric particles by Kassanis, in 1962.
Satellite viruses (SVs) are subviral pathogens that are entirely dependent upon the replication machinery of their helper viruses. There are only four known plant SVs, satellite tobacco necrosis virus, satellite tobacco mosaic virus, satellite panicum mosaic virus, and satellite maize white line mosaic virus.