Bart de Groot
Under the normal rules a target that is not destroyed is again fully repaired in a next mission. An improvement target remains active until it is destroyed. It is not discarded if your missions against it fails, but returns to the active improvement targets, and can be selected again.
There is an optional rule where targets keep their damage between missions. Optional rule "Damaging Targets" on page 17.
If you score at least one-half the Hits needed to Destroy a Target, but less than the Hits needed to Destroy the Target, you Damage the Target. Note on your Log the number of Hits you scored on the Target. You score one-half the Target’s VPs, rounding down. If you later shuffle the Target deck and draw the Target, it begins with the Hits you previously inflicted on it. Do not discard “Improvement” Targets, they remain selectable. If you then Destroy the Target, gain one-half the Target’s VPs, rounding up, and its normal Intel, Infra, and Recon track adjustments. If you select this option, pay 3, 6, or 9 SO’s for Short, Medium, or Long Campaigns.