The Space Pirate defense system is a system of large energy shields that protected the Pirate Homeworld in Metroid Prime 3: Corruption. It was deactivated by Samus Aran in order to clear the way for a large-scale Galactic Federation invasion of that planet. The system consists of a group of large mechanical structures that hover above important targets on the planet's surface and project orange, dome-shaped energy shields. All of these structures are powered by a single large generator located in a secure section of Pirate Command- when Samus deactivates it the shields disappear, but the airborne structures remain in place.
All locations on the Homeworld visited in-game are covered by the shield system, although large areas of Phazon growth seem to be left unprotected. It is unknown whether much of the rest of the planet is also shielded, or only critical areas.
- In the Metroid Manga, Zebes also possessed a planet-wide shield, the Planetary Protection Shield made by the Chozo. When Space Pirates invaded the planet, they brought down the shield using a micro-black hole, however.
- It is unknown whether the defense system is capable of repelling physical matter or simply energy- Samus is forced to circumnavigate the shield through maintenance passages in order to enter the Homeworld, while the Federation assault required its complete deactivation. However, these situations could be explained as a requirement for stealth and a prerequisite to orbital weapons bombardment, respectively, as opposed to a physical aspect of the shield itself.
- Acid Rain is also seen to fall inside even shielded Pirate compounds - it is possible that the shields are in fact large enough for clouds to form inside the barrier.