The Martin NBS-1 was a military aircraft of the United States Army Air Service and its successor, the Army Air Corps. An improved version of the Martin MB-1, a scout-bomber built during the final months of World War I, the NBS-1 was ordered under the designation MB-2 and is often referred to as such. The designation NBS-1, standing for "Night Bomber-Short Range", was adopted by the Air Service after the first five of the Martin bombers were delivered.