Government UAS pilot reported the UAS had a lost link during a mapping mission. The UAS was lost and unrecoverable.

Narrative

An autonomous 2D mapping mission was being conducted over a campus; to include the park immediately to the south of the campus; by the drone unit of the Local Police Department. The mapping route was set up in the control software; FreeFlight 7 for single pass 2D mapping. The drone passed preflight checks and was operating normally upon launch. The drone launched upon command; rose to 150' AGL; then flew to the furthest point away to begin gathering data. The drone flew 4 passes of the planned 14 and was lost. Visual contact was lost and the link with the controller; which had been showing the camera view and GPS location of the drone; was lost at the same time.No anomalies were observed in the drone's flight path or camera operation. The controller had a solid link to the drone; and no warnings displayed at any time. The controller and drone batteries were both over 90% of full at the time of the incident.The drone has not been located or recovered to date.It is believed the drone experienced a catastrophic failure of a critical system such as the battery; control circuitry; or a motor causing the loss.No damage or injuries are believed to have been caused by this incident.