Dorandan firing unit

A powerful energy weapon created by the Ancients, it was located at the Doranda outpost, the site of Project Arcturus. In order to prevent a catastrophic overload, they built this energy weapon as a means to filter the excessive energy. Capable of rotating 360 degrees, it was able to automatically track and fire at ships in orbit. It does not, apparently, have the ability to differentiate between an enemy vessel and a friendly vessel. It was linked directly to the power generator, and, as there is no connection between the power generator and the primary capacitor, the weapon was able to fire a continuous series of shots without pausing to re-energize for another shot.

The weapon has shown to be powerful enough to single-handedly destroy an entire Wraith fleet, and it was stated that one shot would completely obliterate a Puddle jumper.

When the Atlantis Expedition revived Project Arcturus, they unwittingly caused a massive overload, which not only destroyed the weapon and the outpost, but 5/6s of the solar system.