P3X-474
From The Stargate Omnipedia
Planet on the outskirts of the Milky Way Galaxy. The Odyssey crew, minus SG-1 and General Hank Landry, used this planet's Stargate to return to Earth during a barrage of repetitive assaults from Ori warships.
DETAILS
HOME TO - Uninhabited
FIRST APPEARED - Unending
KEY EPISODE
Unending - SG-1 evacuates the entire crew of the starship Odyssey through the Stargate on P3X-474, only to live over 50 years frozen in an Asgard time dilation field above the planet.