To know about the place in NASA where the astronauts learn about the spacewalks and moonwalks, we must understand the concept of The Neutral Buoyancy Laboratory (NBL) which was named after Astronaut Manley L. “Sonny” Carter. Jr.Manley was a physician, aviator and NASA astronaut who died in a civil aviation accident at the age of 43.
NBL prepares the astronauts for space missions that involve spacewalks. It is used by the members of the development team in NASA to improve the flight procedures and verify hardware compatibility. The Neutral Buoyancy Laboratory (NBL) trains astronauts with refine spacewalk procedures during the flight which are essential in any space mission.
Performance of on-orbit assembly and maintenance operations are essential for further space explorations in the future. Several hours of spacewalks for assembly are required by The International Space Station. What we see as an excellent scientific discovery of the Hubble Space Telescope is because of the successful maintenance of spacewalks.
Neutral buoyancy is the equal tendency of an object to sink or float. If an item is made neutrally buoyant through a combination of weights and flotation devices, it will seem to “hover” underwater. Thus even heavy objects can be easily manipulated as if it is the space enduring the zero gravity.
But still, there are certain differences while in space and in NBL. The suits that the astronauts wear whiletraining in the NBL are not truly weightless. The astronauts feel neutrally buoyant, but they nonetheless feel their weight while in their suits. Also, the drag of water hinders motion, making some tasks easier while the others are more difficult to perform in the NBL than in zero gravity.
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) and can hold 6.2 million gallons of water. However, the International Space Station, which is 350 ft x 240 ft cannot fit inside the NBL.
The NBL simulation control areas provide resources for training in facility operations, safety, communications, video support, medicine, suit technicians, support divers, crew training, and technical observers. A medical team is present to monitor and help the condition of all diving personnel. A fully configured hyperbaric chamber is available for any situation of emergency arising due to decompression sickness treatment
The NBL also has systems and personnel to design, manufacture, assemble, test, maintain, reposit, and store neutral buoyancy mockups. Two overhead bridge cranes that can lift up to 10 tons and four jib cranes which can lift up to1.6 tons are used for configuring mockups for every training session. The jib cranes can lift the astronauts into and out of the water.
A voice communication system is available for two-way communication among the astronauts, topside trainers, facility test coordinators, the flight control team within JSC’s Mission Control Center, and the other shuttle crew. There is also a one-way communication to the scuba divers through a radio frequency system or a series of underwater speakers.
Full-scale working models of the shuttle and station robotic arms are also parts of the NBL that are hydraulically operated to improve performance and safety. The flight articles are electrically operated and cannot lift themselves on Earth unlike in the zero-gravity
All divers use oxygen-enriched breathing gas called Nitrox to reduce the bends after long training sessions. Nitrox and cooling water are provided to each spacesuit through umbilicals. The flight spacesuits are self-contained and do not require an umbilical and there are CCTVs that cover the training activities using hard-mounted and handheld cameras.
The Water Treatment System in the Neutral Buoyancy Laboratory recycles the water every 19.6 hours. It is automatically monitored and controlled to a temperature of 82 – 88 degree Fahrenheit to minimize hypothermia. The water is also chemically treated to control contaminant growth and minimize rusting and corrosion of equipment.