A modification to the Sealed Vault quests found by hacking the Ancient Broadcast Stations inside vaults added by the Vanilla Factions Expanded Ancients mod.
Rather than giving you 30 days or so to approach a vault sealed for countless years, you can now approach at your leisure. These quests no longer time out once found.
To prevent anyone else finding such data however, the Broadcast Stations now self destruct once hacked!