Planetary radiation shield

Planetary radiation shield is a colony structure in Master of Orion.

Description
The Planetary Radiation Shield reduces solar and cosmic bombardment to tolerable levels, so that life-forms can comfortably move about a planet�s surface. Radiated worlds become Barren as long as the shield remains in place. The shield also provides a colony with some defense from orbital bombardment, reducing damage.

Strategy
If using this structure to upgrade a Radiated planet to a Barren planet, this structure (or one of its upgrades) needs to remain as per the text above. However, once that planet is terraformed past Barren, then it need not remain for this purpose as it will no longer revert to Radiated.