The Jupiter Outposts was a series of unmanned sensor satellites that were deployed in a network around the planet Jupiter in the Sol system. Their purpose was to serve as an early warning system if any danger threatened Earth, the capital for the United Federation of Planets. The monitoring of the information transmitted from the satellites was examined at Jupiter Station.
In 2367, Jupiter Outpost 92 warned of the approach of a Borg cube; the network did not detect the Breen raid against Earth in 2371, during the Dominion War. As a result of this later failure, Starfleet Command debated whether to scrap the network, as it was considered a relic of older technology. (Decipher RPG module: Worlds)