An Argentine submarine with 44 crew members on board has been missing since Wednesday, according to reports from the nation’s Navy.  Search and rescue efforts are ongoing, and have now been bolstered by both U.S. Navy and NASA aircraft.

Argentinian navy spokesman Enrique Balbi told reporters on Saturday that the ARA San Juan submarine was last seen in the San Jorge Gulf, not far from the coast of southern Argentina’s Patagonia region.  The vessel was underway from Argentina’s Tierra del Fuego archipelago, en route to its home base in Mar del Plata.  The Navy has had no communication with the ARA San Juan since, and has no further information as to its whereabouts or condition.  Had the submarine not gone missing, it would have been due to arrive on Sunday.

“Detection has been difficult despite the quantity of boats and aircraft [in the search],” Balbi told reporters. “Obviously, the number of hours that have passed — two days in which there has been no communication — is of note.”

The Argentinian government search efforts have seen participation from both ships and aircraft, and the U.S. Navy recently began aiding the effort.  It is possible that if the submarine went down, members of the crew may still be alive.  Officials hope that the submarine’s crew may still have the capability to bring the vessel back to the surface even if otherwise disabled, as it would dramatically increase their chances of finding it before it’s too late.