Canon Facts Backstage Info  Speculation

Notes : The Borg sphere has only been seen in action by the Federation on one occasion, during the Sector 001 battle. The last act of the Borg cube destroyed in that battle was to launch a sphere carrying a small group of drones. The sphere generated a temporal vortex, allowing it to travel into the year 2063 in order to prevent the formation of the federation.

The Sovereign class Enterprise-E followed the sphere through the vortex, and observed it firing some form of low energy plasma weapon on Earth. The Enterprise fired a volley of quantum torpedoes at the ship and succeeded in destroying it, although some Borg drones where able to beam aboard the Enterprise and begin assimilating it.

There is little solid evidence concerning the capabilities or numbers of the Borg sphere. It may have been specially constructed solely as a timeship, but this seems unlikely as the Borgs attempt to alter the past appears to have been a last minute plan after the failure of their conventional invasion. The lack of shields and relatively limited armament on this ship suggest that the sphere is some form of science vessel, perhaps with a scouting or courier role also. Given the nature of the Borg, it is likely that they could easily equip this vessel with heavier armament and the statistics above reflect Starfleet projections of a spheres potential combat capability. Given this, the data must me regarded as highly speculative.