Orbit Defense System

From Outscape Wiki

Orbit defense systems protect a planet's inner orbit against intruders and invasions. They perform two key responsibilities: firing at enemy fleets in orbit, and shooting down invasion forces heading towards the planet's surface (drop-capsules carrying assault troops); both are performed automatically. The home planet of a player starts with a pre-built tech-level three orbit defense system.

Orbit Defense System

  Orbit Defense 1.png Orbit Defense 2.png Orbit Defense 3.png
Level 1 2 3
Upgradable Yes No No
Research to unlock Orbit Defense Level 1.png Orbital Defence System Orbit Defense Level 2.png Orbital Security Exclusive to home planet
Civilization specific names
Mankind Small Orbit Defense Large Orbit Defense Orbit Defense
People's Realm Small Orbit Defense Large Orbit Defense Orbit Defense
Ripchee Small Sky Cat Big Sky Cat Sky Cat
Syntis TB13A - Orbit Defense TB13B - Orbit Defense TB13 - Orbit Defense


Level 1 and 2 orbit defense systems each need to be unlocked separately by researching the relevant technology (see 'Research to unlock' in the table above).

Constructing and upgrading

  • Level 1 orbit defense systems can be constructed directly
  • Level 2 orbit defense systems can be built only by upgrading a level 1 Orbit Defense Systems
  • Level 3 orbit defense systems can not be constructed


The following sections describe the responsibilities that an orbital defense system automatically performs for the planet on which it is installed (neither uses ordnance).

Enemy fleets

When an enemy fleet first enters the inner orbit, the orbit defense system will launch a volley of missiles at it. The damage that will be dealt to the fleet depends on the tech-level of the orbit defense system. If the damage dealt is sufficient, the enemy fleet will be destroyed. Multiple fleets in orbit will be attacked in succession, but with a delay between each attack due to the recharge time.

Recharge time

After firing at a fleet in orbit, the orbit defense system cannot fire again until it has recharged. If an attacked fleet wasn't destroyed and remains within the planet's orbit, it will be fired upon again once the recharge time has elapsed.

Invasion force

If an enemy fleet isn't destroyed upon entering a planet's inner orbit, or the orbit defense system is recharging, the fleet could launch an invasion force.

This will trigger the orbit defense system to attack and attempt to destroy the drop-capsules carrying the assault troops before they reach the planet's surface (this function is not affected by the recharge time). The tech-level one and two versions will not be able to destroy all drop-capsules, only a proportion. However, the home planet's tech-level three orbit defense system is capable of annihilating an entire invasion force regardless of its size.

Home planet

The home planet starts with a very powerful, tech-level three orbit defense system pre-built. It is not possible to research or construct additional tech-level three orbit defense systems - the home planet's will be the only one per player. However, tech-level one and two orbit defense systems can be researched and constructed on other planets colonized by a player.

Other planets

If the appropriate research has been completed, it's possible to construct tech-level one and two orbit defense systems on any planet colonized by a player.

Multiple installations

If multiple orbit defense systems are built on the same planet they work cumulatively, where the total damage per shot is the sum of all, but the recharge and anti-invasion rates are of the highest. The following table shows this with an example based on 1 small and 1 large orbit defense structures built.

  Quantity Damage Recharge Anti-invasion
Small Orbit Defense 1 1,000 3,600 20%
Large Orbit Defense 1 2,000 3,600 50%
Totals: 2 3,000 3,600 50%


It's possible that a planet's orbital defense systems could be destroyed during an orbital bombing campaign (even the home planet's).

Stats & Upgrade costs

MankindSmall Orbit Defense1Large Orbit Defense10018025%10,00010020,0005,0007,200
MankindLarge Orbit Defense2Orbit Defense15018050%10,00015020,00025,00043,200
MankindOrbit Defense3-15018075%10,00020020,000100,00086,400
People's RealmSmall Orbit Oppressor1Large Orbit Oppressor10018025%10,00010020,0005,00043,200
People's RealmLarge Orbit Oppressor2Orbit Oppressor15018050%10,00015020,00025,00086,400
People's RealmOrbit Oppressor3-15018075%10,00020020,000100,000129,600
RipcheeSmall Sky Cat1Big Sky Cat10018025%10,00010020,0005,00043,200
RipcheeBig Sky Cat2Sky Cat15018050%10,00015020,00025,00086,400
RipcheeSky Cat3-15018075%10,00020020,000100,000129,600
SyntisTB13A - Orbit Defense1TB13B - Orbit Defense10018025%10,00010020,0005,00043,200
SyntisTB13B - Orbit Defense2TB13 - Orbit Defense15018050%10,00015020,00025,00086,400
SyntisTB13 - Orbit Defense3-15018075%10,00020020,000100,000129,600


  • Level: the tech-level
  • Upgrade: whether the structure can be upgraded to another
  • Damage: total damage done per-shot to fleet in orbit
  • Recharge: time required (in seconds) to be able to fire again at a fleet in orbit
  • Anti-invasion: proportion of an invasion force (assault troops in drop-capsules) likely to be destroyed before reaching the planet's surface
  • Personnel: number of colonists required to operate (contributes to employment)
  • PC (Power Consumption MWt): amount of colony power required
  • Be (Beron): cost in beron
  • Credits: cost in credits
  • Build: build time in seconds