Unmanned aircraft systems are regulated by the _____

The regulation of unmanned aircraft systems (UAS), commonly referred to as drones, falls under the purview of the Federal Aviation Administration, or FAA. The FAA is the government agency responsible for the safety and regulation of civil aviation in the United States. It establishes and enforces regulations regarding the operation of UAS to ensure safety in the national airspace.

The FAA's role includes developing guidelines for drone operations, issuing certifications for commercial drone use, and setting rules concerning airspace restrictions and operational requirements. This regulatory framework is critical for maintaining order and safety as the use of UAS continues to grow in various sectors, including commercial, recreational, and governmental operations.

Other organizations mentioned in the options have distinct roles that do not directly involve the regulation of UAS. For instance, NASA primarily focuses on aerospace research and development, the United States Postal Service (USPS) manages postal services, and the Department of Transportation (DOT) has a broader role in overseeing transportation systems but delegates aviation regulation specifically to the FAA. Thus, the FAA is the correct choice as it is specifically charged with the oversight of unmanned aircraft systems.