Complex sentence: Both stages are covered with a layer of ablative cork, have parachutes to land them gently in the sea and have been marinized by using materials that resist salt-water corrosion, anodizing and paying attention to galvanic corrosion.
Split into simpler sentences: Both stages are covered with a layer of ablative cork and possess parachutes to land them gently in the sea. The stages are also marinized by salt-water corrosion resistant material, anodizing and paying attention to galvanic corrosion.