Lagrangian Point satellite

"This might be the single largest weapons platform ever constructed."

- Brendan Gall

Lantean defense satellites were spaceborne weapons platforms created by the Lanteans and put to extensive use during their war with the Wraith.

Overview
"According to the Ancient database, [the satellite] should be able to take out all three [hive-ships] when fully charged. Keep in mind that the Ancient technology was far superior—they only lost the war because they were vastly outnumbered."

- Rodney McKay

Though nearly as large as a Goa'uld Ha'tak, these satellites have relatively little internal space, with only a control room accessible via an airlock capable of docking with a single gateship. Its power requirements are also fairly low, to the point where its primary weapon could be run using a single naquadah generator. Each satellite carries at least one beam weapon powerful enough to split a hive-ship in half with a single shot, far exceeding the power of even the most potent Asgard weapons; it was stated that this weapon would be more than capable of destroying at least three hive-ships when fully charged, likely with more than half of its buffer still charged. Whether that is the full extent of its armament, and whether it had any defensive measures for protection, is unknown. The charging rate of the weapon is rather slow due to the relatively weak amount of power produced by a naquadah generator, but is is likely that the capacitor would refill significantly faster if a more powerful energy source, such as a ZPM, was attached to it (assuming a capacitor would even be needed, as a stronger power source would likely be able produce enough power to fire the weapon almost immediately).

History
"I don't mean to put any undue pressure, but at this moment that satellite is the only thing standing between the Wraith and Atlantis."

- Elizabeth Weir

Several of these satellites were placed throughout the Lantean system, though most were destroyed by the Wraith during their march towards Atlantis. At least one such satellite was located at one of the system's Lagrangian points, and was later discovered by the Atlantis Expedition; it had suffered some damage though, and its power supply was depleted. When the Wraith sent three hive-ships to destroy the newly reinhabited Atlantis once and for all, a three-man team from Atlantis managed to reactivate the satellite and used it to destroy one of the three hive-ships. Unfortunately, the satellite was too badly damaged to fire again, and the remaining hive-ships destroyed the satellite before the problem could be fixed.