By sending Constructors to a Starbase, a base may be upgraded to improve its performance or defense. As with the initial Starbase, the Constructor is sacrificed to create the improvement. While many improvements come free of charge (except the construction cost of the Constructor), some come with an additional cost. However, this fee is waived for those of evil alignment.
Note that some United Planets decisions may restrict the number of upgrade modules.
Defensive Modules[]
These may be added to any Starbase. They provide sensors as well as giving attack and defense against enemy ships that attempt to attack it.
| Upgrade Name | Tech | Cost | Module Requirement | Effect |
| Battle Stations | Space Weapons | 200 | Beam Weapon, Missile, Mass Driver attack +1 | |
| Battle Stations II | Medium Scale Building | 100 | Battle Stations | Beam Weapon, Missile, Mass Driver attack +2 |
| Battle Stations III | Large Scale Building | 100 | Battle Stations II | Beam Weapon, Missile, Mass Driver attack +4 |
| Battle Stations IV | Massive Scale Building | 200 | Battle Stations III | Beam Weapon, Missile, Mass Driver attack +6 |
| Subspace Blaster | Starbase Fortification | 0 | Battle Stations | Beam Weapon attack +5 |
| Subspace Blaster II | Starbase Fortification Mark II | 0 | Beam Weapon attack +10 | |
| Subspace Blaster III | Starbase Fortification Mark III | 0 | Beam Weapon attack +30 | |
| Devastation Beam | 0 | Battle Stations | Beam Weapon attack +7 | |
| Star Javelin | Starbase Fortification | 0 | Battle Stations | Missile attack +5 |
| Star Javelin II | Starbase Fortification Mark II | 0 | Missile attack +10 | |
| Star Javelin III | Starbase Fortification Mark III | 0 | Missile attack +30 | |
| Matter Detinators | Blackhole Eruptor | 0 | Battle Stations | Missile attack +7 |
| Ship Pounder | Starbase Fortification | 0 | Battle Stations | Mass Driver attack +5 |
| Ship Pounder II | Starbase Fortification Mark II | 0 | Mass Driver attack +10 | |
| Ship Pounder III | Starbase Fortification Mark III | 0 | Mass Driver attack +30 | |
| Atlas Sling | Singularity Driver | 0 | Battle Stations | Mass Driver attack +7 |
| Ray-Shielding | Starbase Fortification | 0 | Battle Stations | Shields defense +5 |
| Ray-Shielding II | Starbase Fortification Mark II | 0 | Ray-Shielding | Shields defense +10 |
| Ray-Shielding III | Starbase Fortification Mark III | 0 | Ray-Shielding II | Shields defense +20 |
| Invulnerability Bloom | Advanced Force Fields | 0 | Battle Stations | Shields defense +16 |
| Missile Defender | Starbase Fortification | 0 | Battle Stations | Point Defense defense +5 |
| Missile Defender II | Starbase Fortification Mark II | 0 | Missile Defender | Point Defense defense +10 |
| Missile Defender III | Starbase Fortification Mark III | 0 | Missile Defender II | Point Defense defense +20 |
| Electro-Magnetic Surge | Aereon Missile Defense | 0 | Battle Stations | Point Defense defense +16 |
| Combat Armor | Starbase Fortification | 0 | Battle Stations | Armor defense +5 |
| Combat Armor II | Starbase Fortification Mark II | 0 | Combat Armor | Armor defense +10 |
| Combat Armor III | Starbase Fortification Mark III | 0 | Combat Armor II | Armor defense +20 |
| Overlord Armor | Zero-Point Armor | 0 | Battle Stations | Armor defense +16 |
| Perimeter Scanners | Sensors | 0 | Sensors range +1 | |
| Sector Scanners | Sensors Mark II | 100 | Perimeter Scanners | Sensors range +2 |
| Sector Surveillance Scanners | Sensors Mark III | 150 | Sector Scanners | Sensors range +3 |
| Ultimate Surveillance Scanners | Sensors Mark IV | 200 | Sector Surveillance Scanners | Sensors range +4 |
Economic Modules[]
These may be added to Economic starbases. They enhance the military production, social production, and research of planets in the area of effect as well as increase trade revenue of passing Freighters.
| Upgrade Name | Tech | Cost | Module Requirement | DL Effect | TA Effect |
| Starbase Factory | 0 | Planet production/research +3% | +5% | ||
| Adv. Starbase Factory | Xeno Industrial Theory | 0 | Starbase Factory | Planet production/research +5% | +5% |
| Massive Scaling Center | Xeno Factory Construction | 0 | Adv. Starbase Factory | Planet production/research +7% | +4% |
| Smart Drones | Advanced Computing | 0 | Massive Scaling Center | Planet production/research +10% | +4% |
| Interstellar Collectors | Manufacturing Centers | 0 | Smart Drones | Planet production/research +10% | +4% |
| Orbital Replicators | Industrial Sector | 0 | Interstellar Collectors | Planet production/research +15% | +3% |
| Trading Post | Trade | 0 | Trading income + 10% | ||
| Advanced Trading Post | Advanced Trade | 0 | Trading Post | Trading income + 20% | |
| Trade Center | Master Trade | 0 | Advanced Trading Post | Trading income + 30% |
Influence Modules[]
These may be added to Influence starbases. They enhance the influence generated by the starbase.
| Upgrade Name | Tech | DL Cost | TA Cost | Module Requirement | DL Effect |
| Diplomatic Outpost | 0 | 500 | Influence +5% | ||
| Foreign Relations Center | Universal Translator | 100 | Diplomatic Outpost | Influence +7% | |
| Interstellar Embassy | Diplomatic Relations | 200 | Foreign Relations Center | Influence +10% | |
| Galactic Mall | 250 | Foreign Relations Center | Influence +10% | ||
| Xeno Concert Hall | Extreme Entertainment | 250 | Galactic Mall | Influence +15% | |
| Galactic Forum | Advanced Diplomacy | 300 | Interstellar Embassy | Influence +15% | |
| Interstellar Consortium | Xeno Business | 0 | Interstellar Embassy | Influence +20% | |
| Franchise Center | Cultural Domination | 100 | Interstellar Consortium | Influence +25% | |
| Supreme Forum | Expert Diplomacy | 300 | Galactic Forum | Influence +25% | |
| Franchise Headquarters | Historical Assimilation | 200 | Franchise Center | Influence +30% | |
| Cultural Maximization Center | Xeno Cultural Trends | 200 | Franchise Headquarters | Influence +50% | |
| Insurrection Coordinator | Cultural Insurrection | 200 | Cultural Maximization Center | Influence +75% | |
| Cultural Conquest Center | Cultural Conquest | 300 | Insurrection Coordinator | Influence +100% |
Mining Modules[]
These may be added to Mining starbases. They enhance the return of the mined resource.
| Upgrade Name | Tech | Cost | Module Requirement | DL Effect | TA Effect |
| Mining Barracks | 0 | Resource gain +2 % | Resource gain +5 % | ||
| Mining Center | Xeno Engineering | 0 | Mining Barracks | Resource gain +3 % | Resource gain +5 % |
| Mining Headquarters | Xeno Industrial Theory | 0 | Mining Center | Resource gain +5 % | Resource gain +5 % |
| Resource Excavation | Xeno Factory Construction | 0 | Mining Headquarters | Resource gain +7 % | Resource gain +5 % |
| Extraction Center | Manufacturing Centers | 0 | Resource Excavation | Resource gain +10 % | Resource gain +5 % |
| Extraction Complex | Manufacturing Centers | 0 | Extraction Center | Resource gain +12 % | |
| Resource Sector | Industrial Sector | 0 | Extraction Complex | Resource gain +15 % | Resource gain +5 % |
Military Modules[]
These may be added to Military starbases. They enhance the attack, defense, and speed of ships in the area of effect.
| Upgrade Name | Tech | Cost | Module Requirement | Effect |
| Protection Fields | Starship Defenses | 100 | Battle Stations | Ship Shields, Point Defense, Armor defense +1 |
| Beam Intercepter | Starbase Defenses | 0 | Battle Stations | Ship Shields defense +2 |
| Energy Grid | Starbase Defenses | 0 | Ship Armor defense +2 | |
| Missile Defender | Starbase Defenses | 0 | Ship Point Defense defense +2 | |
| Fighter Drones | Space Weapons | 300 | Battle Stations | Ship Beam Weapon attack +1 |
| Beam Multiplier Field | Starbase Mobilization | 300 | Beam Intercepter | Ship Beam Weapon attack +1 |
| Beam Multiplier Field III | Starbase Projection | 400 | Beam Multiplier Field | Ship Beam Weapon attack +2 |
| Beam Multiplier Field IV | Superior Starbase Defense Systems | 500 | Beam Multiplier Field III | Ship Beam Weapon attack +3 |
| Beam Multiplier Field V | Starbase Conquest Strategy | 500 | Beam Multiplier Field IV | Ship Beam Weapon attack +4 |
| Omega Cannon | Starbase Mobilization | 300 | Energy Grid | Ship Mass Driver attack +1 |
| Omega Cannon III | Starbase Projection | 400 | Omega Cannon | Ship Mass Driver attack +2 |
| Omega Cannon IV | Superior Starbase Defense Systems | 500 | Omega Cannon III | Ship Mass Driver attack +3 |
| Omega Cannon V | Starbase Conquest Strategy | 500 | Omega Cannon IV | Ship Mass Driver attack +4 |
| Missile Bloom | Starbase Mobilization | 300 | Missile Defender | Ship Missile attack +1 |
| Missile Bloom III | Starbase Projection | 400 | Missile Bloom | Ship Missile attack +2 |
| Missile Bloom IV | Superior Starbase Defense Systems | 500 | Missile Bloom III | Ship Missile attack +3 |
| Missile Bloom V | Starbase Conquest Strategy | 500 | Missile Bloom IV | Ship Missile attack +4 |
| Sniper Turrets | MiniBalls | 300 | Ship Mass Driver attack +1 | |
| Graviton Snipers | Graviton Driver IV | 400 | Sniper Turrets | Ship Mass Driver attack +2 |
| Neutrino Snipers | Neutrino Bullets | 500 | Graviton Snipers | Ship Mass Driver attack +4 |
| Laser Equalizer | Laser | 300 | Ship Beam Weapon attack +1 | |
| Hyper-Phasors | Phasors | 400 | Plasma Equalizer | Ship Beam Weapon attack +2 |
| Focused Disruptors | Disruptors | 500 | Hyper-Phasors | Ship Beam Weapon attack +4 |
| Missile Launchpads | Missile Weapon Theory | 300 | Ship Missile attack +1 | |
| Sub-Space Warheads | Photonic Torpedo II | 400 | Missile Launchpads | Ship Missile attack +2 |
| Blackhole Torpedo | Blackhole Eruptor | 500 | Sub-Space Warheads | Ship Missile attack +4 |
| Stellar Wake | Warp Drive | 0 | Ship Speed +1 | |
| Inverse Tractor Beam | Warp Drive IV | 0 | Ship Speed +1 | |
| Interdiction Beam | HyperWarp | 0 | Enemy ship Speed -1 |