Scansats were non-mobile surveillance devices used by the Royal Manticoran Navy.
Because they did not have to generate an impeller wedge, they have a longer life-span than recon drone. However, their stealth systems were fairly rudimentary, making them relatively easy to spot.
Patrolling RMN warships made a routine out of seeding the outer volumes of their star systems of responsibility with FTL scansats. (HH10)