Since each ship or PDB is damaged independently in combat, the damage is persistent to that combat asset. In addition, a planet's technologies will increase and the combat asset may require a retrofit. In each of these cases, the asset can be placed within the shipyard for repairs.
There are two ways to repair ships, and one way to repair a PDB. Ships can be repaired using either a Mobile Shipyard, or the planetary shipyard. PDB can only be repaired at their planet of origin. Repairs take on the technology level of the shipyard and all repairs cost the technology level increase plus a docking fee.
For planetary shipyard repairs, from the main menu, select either the Fleet/Fleet Maintenance or PDB/PDB Maintenance menu item. Use the maintenance interface to select the asset that needs to be repaired. There must also be at least one build slot available at that planet. Ships or PDB of the same type can be queued up for repair at the planetary shipyard. Repairs to a different ship or PDB type will require another available build slot.
The fleet seeking repairs must be in a planetary defense position over the planet whose shipyard the fleet wants to use. No ship can be built or repaired unless the shipyard is large enough to handle it. Ships can be repaired at a shipyard owned by the fleet commander, if the yard is free, the yard is large enough, and there are enough local resources to make the repair. When selected for repair, the ship will be removed from the fleet and docked for repairs. The ship will take on the technology of the planet or Mobile Shipyard performing the refit.
For Mobile Shipyard repairs, from the main menu, select the Fleet/Fleet Orders and then select the Fleet Details links (The Fleet ID or Fleet Name link). Then select the individual Mobile Shipyard link (The Ship ID or Ship Type) to get to the Mobile Shipyard Ship Details page. On this page, will be a 'Use Mobile Shipyard' button. Selecting this button will take you the Mobile Shipyard maintenace page. Navigate this page like the planetary shipyard maintenance page.
The ship to be repaired and the Mobile Shipyard should both be within the same fleet. When using a Mobile Shipyard, the fleet must not be in transit. Loading the repair ship requires the fleet be stationary. Once the ship is loaded into the Mobile Shipyard, the fleet can be moved while repairs are underway. Resources for repair are drawn from any cargo ship in the fleet.
Mobile Shipyard are similar to planetary shipyards except they can repair only one ship at a time. The Mobile Shipyard can only begin repairs when the fleet is stationary and can complete repairs while in transit.
The Fleet Maintenance page will allow the commander to step through the local fleet. As each ship is displayed, it is compared against the capabilities of the local shipyard. The refit resource cost and the Refit link will appear if the ship can be repaired. To effect a repair, select the Refit link and the ship will be removed from the fleet.
No PDB can be built or repaired unless the shipyard is large enough to handle it. PDB can be repaired, if the yard is free, the yard is large enough, and there are enough local resources to make the repair. When selected for repair, the PDB will be removed from service.
The PDB Maintenance page will allow the commander to step through the local defenses. As each PDB is displayed, it is compared against the capabilities of the local shipyard. The refit resource cost and the Refit link will appear if the PDB can be repaired. To effect a repair, select the Refit link and the PDB will be removed from service.