The Argentine Armada (Navy) diesel-electric attack submarine referred to as the ARA San Juan (S-42) had been out of radio contact for three days. And now, the U.S. Navy and NASA join the search for the missing submarine with its crew of 44 sailors.
ArsTechnica reports that NASA sent a modified P-3 Orion patrol plane to help search the missing submarine, which was built in 1983 by the German shipbuilder Thyssen Nordseewerke. This NASA plane is used by the Navy for submarine hunting in the past. It has a magnetic anomaly detector or also referred to as magnetometer, infrared cameras, a gravimeter for identifying small fluctuations in the planet's gravity and other sensors for gauging ice thickness. Probably, the NASA plane could detect the whereabouts of the submerged submarine with this equipment.
Meanwhile, the U.S. Southern Command (SOUTHCOM) ordered the U.S. Navy to send a P-8A Poseidon multi-mission maritime aircraft to help search for the missing submarine as requested by the government of Argentina. It stated that the aircraft and its 21-person crew will depart El Salvador's Comalapa Air Base. The P-8A Poseidon also took part in the search for The Republic of Korea ship named Stella Daisy, which sank in the Southern Atlantic, off the western coast of Africa.