The Neutral Buoyancy Laboratory (NBL) is an astronaut training facility and neutral buoyancy pool operated by NASA and located at the Sonny Carter Training Facility, near the Johnson Space Center in Houston, Texas.

[2] The NBL's main feature is a large indoor pool of water,[3] in which astronauts may perform simulated EVA tasks in preparation for upcoming missions.

Trainees wear suits designed to provide neutral buoyancy to simulate the microgravity that astronauts experience during spaceflight.

NASA purchased the structure that now holds the NBL from McDonnell Douglas in the early 1990s and began refitting it as a neutral-buoyancy training center in 1995.

[5][6] The NBL contains full-scale mock-ups of International Space Station (ISS) modules and payloads, as well as visiting vehicles such as the Japan Aerospace Exploration Agency (JAXA) HTV, the European Space Agency ATV, the SpaceX Dragon, and the Orbital Sciences Corporation Cygnus.