The Neutral Buoyancy Laboratory (NBL)

Sonny Carter Training Facility Manley L. "Sonny" Carter, Jr. (August 15, 1947 - April 5, 1991) was a physician, aviator, astronaut.  He  died in a civil aviation accident at the age of 43.   The mission of the Neutral Buoyancy Lab is to prepare for space mission involving space walks or extravehicular activity.   NASA team members utilize the NBL to develop flight procedures, verify hardware compatibility, train EVA astronauts, and refine EVA procedures during flight that are necessary to ensure mission success.   NBL Resources NBL Photo Gallery   The Sonny Carter Training Facility and the Neutral Buoyancy Laboratory   Neutral Buoyancy is the the term used to describe something that has an equal tendency to float as it does to sink.  Articles that are configured to be neutrally but naturally buoyant items can be easily manipulated much like an orbit. 1.)  A suited astronaut in the NBL is not truly weightless.  It is true that the suit/astronaut combination is neutrally buoyant. The astronauts do feel their weight while in the suit.   2.) Water drag acts to hinder motion; this makes some things easier to do in the NBL than on orbit and some things more difficult.  Even with the limitations, neutral buoyancy is currently the best available method for long-duration EVA training.   NBL Size The NBL is 202 ft. in length, 102 ft in width, and 40 ft in depth (20 ft above ground level and 20 ft below).  It holds 6.2 million gallons of water.       The NBL simulation control areas provide resources for all disciplines involved in the execution of EVA training sessions including facility operations, safety, communications, video support, medicine, suit technicians, support divers, crew training, and technical observers.   More about the NBL A medical team is present to monitor the condition of all dive personnel. A full complement of voice communication systems is available including two-way communication among suited astronauts, topside trainers, facility test coordinators, the flight control team within JSC's Mission Control Center, and the remainder of the shuttle crew at the on-site Shuttle Mission Simulator. Full-scale working  models of the shuttle and station robotic arms are critical NBL components.  Because of the pressures encountered at depth, all divers use oxygen-enriched breathing gas (Nitrox) to reduce the probability of experiencing the bends after long training session.  The breathing gas and cooling water are provided to each space suit through umbilicals. Video coverage of all training activities is accomplished using hard-mounted and hand-held cameras.  The video is used by the topside trainers and simulation control team and is transmitted to on-site training facilities.  The water within the NBL is recycled every 19.6 hours.  It is automatically monitored and controlled to a temperature of 82-88 degrees fahrenheit to minimize the potential effects of hypothermia on support divers.  It is also chemically treated to control cantaminant growth while minimizing long-term corrosion effects on training mock-us and equipment.