Even a thriving S-class frontier town faces three recurring crises tracked alongside its core meters: Sentinel raids driven by rising alert, biological brood infestations, and maintenance debt spirals. Ignoring a distressed settlement for weeks will never raze its buildings or delete your claim, so you cannot permanently lose a town while away on an Expedition. However, an unanswered raid or festering debt freezes warehouse payouts completely and leaves citizen Happiness bruised when you finally step off your starship.
Sentinel raids and corrupted drone waves
Every settlement accumulates Sentinel Alert passively over time, climbing much faster on aggressive Sentinel worlds or in towns saddled with high-profile mining traits. When the alert bar hits 100 percent, a raid triggers and pauses in stasis until you physically enter settlement airspace, meaning settlers never win or lose the battle off-screen. Defeating the attacking drones, Quads, and Hardframe mechs drops Salvaged Glass, Pugneum, and Sentinel shells while resetting alert to zero; fleeing or failing the defense slashes citizen Happiness. Note that owning a town also triggers the quest A Trace of Metal after your early raids, unlocking your friendly Laylaps drone companion and Minotaur Hardframe armour.
Brood infestations and perimeter suppression
Separate from machine patrols, towns can roll biological infestation alerts where vile brood horrors and whispering-egg swarms erupt along the street perimeter. Clearing the wave rewards Larval Cores and protects citizen morale and population. To stop fighting on every single visit, upgrade Watchtowers and Radar Arrays toward S-class at their building terminals and favour policy rulings that add cloaking or Sentinel-dampening perks, cutting daily alert gain down to a crawl.
Breaking out of a maintenance debt spiral
New Overseers often panic when a fresh C-class settlement racks up hundreds of thousands of Units in debt after approving a Saloon or Dwelling. Because town debt never touches your personal Units and can only be worked off by positive Net Output, pause all high-upkeep residential builds whenever Maintenance exceeds Productivity. Walk straight to an existing Farm or Warehouse terminal, invest alloys and cogs to push that building to A-class or S-class, and watch daily Productivity vault past Maintenance so the debt clock counts smoothly down to zero.