Markham will take over at agency’s west branch in St. Louis, assisting with the integration of NGA’s activities across the western United States. According to an NGA press release, Markham will oversee the NGA Operations Center, the Office of NGA Defense, the Office of Expeditionary Operations, an NGA leadership at the three National Reconnaissance Office Aerospace Data facilities.

“I know [dual-hatting] is a departure from past practices, but I strongly believe it reflects how the position and our leadership structure has evolved,” Cardillo said. “[Brett] knows the mission, the workforce and the community.”

Prior to this appointment, Markham served as the agency’s director of analytic operations in the analysis directorate. Over the course of his 28 year naval career Markham served in various analytic, staff and leadership positions that included five strategic deterrent patrols, three carrier deployments, and service at three Combatant Commands and the Joint Staff. Markham also served as the deputy director of intelligence for North American Aerospace Defense Command and the United States Northern command.

The ARA San Juan and its sailors went missing Wednesday, Nov. 15, after departing the city of Ushuaia and following a series of naval exercises. The submarine reported a technical breakdown and had to re-navigate to the Mar Del Plata, making its last reported contact near the Argentine coast.

However, a lack of contact with the sub necessitated involvement from NASA and the U.S. Navy as well as eight nations, including Brazil, South African and the United Kingdom.

On Saturday, Nov. 18, the U.S. Navy’s Undersea Rescue Command deployed two independent rescue assets including a Submarine Rescue Chamber that can rescue six people at a time while reaching depths of 850 feet. It also offered a Pressurized Rescue Model that submerges up to 2,000 feet for docking and mating with a submarine settled on the ocean floor.

The Navy also has the ability to deploy unmanned underwater vehicles that use sonar technology for searching out targets. The New York Post showcased the Bluefin 12D as one such vehicle, and cited its ability to run for 30 hours at a depth of around 5,000 feet.

NASA’s prime asset in the search for the San Juan is a P-3 Orion patrol plane, which was originally introduced in the 1960s as an anti-submarine surveillance craft. The plane employs a magnetic anomaly detector, or magnetometer, a gravimeter for analyzing small gravity fluctuations, and infrared cameras and sensors that are traditionally used measure ice thickness.

The Argentine military had previously detected what they thought were communication attempts from the submarine via seven satellite messages. However, Argentine navy spokesman Enrique Balbi indicated that said messages turned out not to be from the San Juan.