New photos of the still classified U.S. Air Force’s Lockheed Martin RQ-170 Sentinel reconnaissance unmanned air vehicle have emerged from Vandenberg AFB, California.

Developed in secret in the 1990s, the existence of the UAV became public in 2007 when the 65.5-ft span aircraft was first seen in Afghanistan. The Sentinel is operated by the Air Force’s 30th Reconnaissance Squadron which is generally assigned to the 432d Air Expeditionary Wing at Creech AFB, Nevada.  However, a detachment of the reconnaissance unit was also set up six years ago at Vandenberg, as evidenced for the first time by this sighting.

The images, taken on Feb. 28 while photographers were visiting the base prior to the March 1 launch of the Air Force’s NROL-79 reconnaissance satellite on an Atlas V, appear to show the RQ-170 is uniquely configured for testing within the extensive Navair-controlled Point Mugu sea range. This 36,000 square mile facility extends for almost 260 miles along the California coast and around 200 miles out into the Pacific Ocean. The facility is thought to be the world’s largest instrumented over-water range for multi-service test, development and training operations in electronic-combat environments.

The Sentinel pictured at Vandenberg is equipped with a large air data sensor probe, not previously seen on other sightings. The aircraft also appears to have a large dielectric panel painted in black radio-transparent paint mid-span on the lower surface of the port wing and is also configured with the active electronically scanned array surveillance and tracking radar system previously seen on earlier photos.

Although largely dedicated to national security space launches and missile testing, Vandenberg has also played a role as the recovery site for three Air Force X-37B Orbital Test Vehicle missions from 2010 onward.