Attero device

"It's an end game machine...if it works the way I think it does, it would mean the end of the Wraith once and for all."

- Rodney McKay

The Attero device was an endgame machine created by the rogue Lantean scientist Janus as a means of destroying the Wraith species in its entirety.

Overview
"...if this machine is capable of actually functioning safely, it disrupts the very specific sub-space frequencies the Wraith use." "So they wouldn't be able to engage their hyperdrive" "Well, that's the genius. They would be able to engage their hyperdrives. It's just that their particular channel of sub-space would be destabilized and their ship would be ripped into a million pieces."

- Rodney McKay and Daniel Jackson

The device was designed to disrupt the subspace frequencies associated with Wraith hyperdrive systems, causing Wraith ships to be destroyed as they passed through a hyperspace window. Since hyperdrives are unique to the species using them, Lantean vessels would still be able to travel across the galaxy and attack the stranded vessels or just let the Wraith die from starvation in the vacuum of space. Unfortunately, it had the unforeseeable side effect of causing energy to build up behind the event horizon of a Stargate's wormhole, destroying a Stargate whenever an address was dialed. As a result of this devastating side effect, Janus abandoned the entire project.

History
"So, what's the catch?" "Ah, well, the catch is that Janus ran a three day test about ten thousand years ago and then shut the whole project down because of 'unforeseen side effects'."

- Daniel Jackson and Rodney McKay

10,000 years ago Janus first tested the Attero device for three days, but then shut it down due to "devastating and unforeseen side effects", which was later revealed to be causing Stargates to explode with the force of a dozen nuclear warheads.

The device was rediscovered in 2008 by Dr. Rodney McKay and Dr. Daniel Jackson in Janus' research outpost. After being taken there by the Lost Tribe, they were forced to activate it using a device from Janus' lab in Atlantis. This caused a duo of Wraith cruisers to be destroyed and Todd to believe that the Atlantis Expedition had located and deliberately activated the device. Believing he was betrayed, Todd hijacked the Daedalus. Upon discovering the side effects of the device, McKay attempted to shut down the device, but was stunned before he was able to complete the process. While the device remained active it destroyed Atlantis' Stargate and the control room; luckily a manipulation of Atlantis' shield prevented the blast from destroying the entire city. At least one other planet ended up being affected by this: the Travelers built a colony on a planet for the first time in generations and it was destroyed along with two Travelers ships, one of which was their Ancient Warship, when the Stargate exploded in an explosion so powerful that it could be seen from space. Larin dispatched a ship to Atlantis for answers and Colonel Sheppard and Zelenka boarded it to go to M6H-987 where the device was.

Meanwhile, Todd took the Daedalus to the planet as well. Along the way it was partially disabled by Ronon and weapons were beyond repair so Todd set a collision course with the facility while he and his men escaped in their Wraith Transport. The Lost Tribe was revealed to be Asgard who were using the device to get rid of the Wraith so they could leave their dying world and move out into the galaxy without being bothered by the Wraith. They didn't use the Stargates so they didn't care about the device's side-effects. The Traveler's ship arrived and 2 of the 3 Asgard ships engaged it to protect the device. McKay and Daniel broke free and managed to disable the device by removing the control crystal from the antenna, though Daniel was badly injured in the attempt. Two of the Asgard ships were destroyed by the Travelers ship and the third escaped to hyperspace. The Daedalus was prevented from crashing into the device due to being jumped into hyperspace and the human crew regained control. McKay and Daniel were beamed aboard the Daedalus and Sheppard on the Traveler's ship destroyed the device by blasting the complex to smithereens with the Traveler ship's weapons.

Trivia

 * The term "Attero" is a Latin word that translates into "to weaken" or "destroy".