The satellites would be deployed in orbit of a targeted planet by a mothership, and were designed to operate autonomously in a network of several satellites. Although they could function independently, a mothership could assume control of all satellites in the network by remote control, and all command functions would be routed for the mothership. The satellites computer systems were protected by a type of force field, and maintained at least one back-up system should the main system become damaged or disabled.
The satellites were equipped with directed energy weapons which were used for planetary bombardment, as well as deflector shields for defense. However, the deflector shields were rather weak and there effectiveness was severely reduced when subjected to only one blast from a Federation phaser.
In 2257, the crew of the USS Constitution encountered six N'shaii satellites in orbit of Sordinia IV. Although suffering heavy damage from the satellites' directed energy weapons, a boarding party was able to get aboard one of the satellites and relay data back about the satellites' networked systems. The crew soon devised a way to take down the network, but their plan was hampered by the arrival of a mothership. However, after sabotaging the mothership's control of the network, the Constitution was able to take down the satellites and take one aboard so it could be studied. (TOS - My Brother's Keeper novel: Constitution)