In 1965, while performing tests at the NASA facility now known as Johnson Space Center a subject was accidentally exposed to a near vacuum (less than 1 psi) when his space suit leaked while in a vacuum chamber. He did not pass out for about 14 seconds, by which time unoxygenated blood had reached his brain. Technicians began to repressurize the chamber within 15 seconds and he regained consciousness at around the equivalent of 15,000 feet of altitude. He later said that his last conscious memory was of the water on his tongue beginning to boil.