NASA Extreme Environment Mission Operations, or NEEMO, is a NASA analog mission that sends groups of astronauts, engineers and scientists to live in the Aquarius underwater laboratory, the world's only undersea research station, for up to three weeks at a time in preparation for future space exploration.

The Aquarius Reef Base is an underwater habitat located 5.4 mi (8.7 km) off Key Largo in the Florida Keys National Marine Sanctuary, Florida, United States. It is the world's only undersea research laboratory and it is operated by Florida International University. It is deployed on the ocean floor 62 ft (19 m) below the surface and next to a deep coral reef named Conch Reef.