Official rule text
17.2 A captured non-fighter ship or mech is returned under the rolls do not affect bombardment rolls. following circumstances: d Multiple planets in a system may be bombarded, but a a If the player who captured the unit agrees to return it as part player must declare which planet a unit is bombarding of a transaction. before making a bombardment roll. b If an ability instructs the capturing player to return the unit e The L1Z1X’s “Harrow” ability does not affect the L1Z1X as part of an ability’s cost. player’s own ground forces. c If the player whose unit was captured blockades a space f Planets that contain a unit with the “Planetary Shield” dock of the player who captured the unit. ability cannot be bombarded.