A long-standing space mystery that has plagued NASA staff seems to have been solved. NASA and the international space station (ISS) staff have been plagued by an air leak at the end of 2019, which has finally shrunk in a new round of testing. < / P > < p > NASA astronauts Chris Cassidy, Russian space agency astronauts Anatoly ivanishin and Ivan Wagner conducted a series of tests, including closing the doors around the station so that NASA can monitor the air pressure in each section. After one by one investigation, NASA finally identified the air leak from the main working area of the Zvezda service module. < / P > < p > the Zvezda service module built in Russia contains living quarters as well as life support, communication and propulsion systems. This Tuesday, NASA wrote in an additional statement to locate the exact source of the leak. The space agency stressed that the leak did not pose a direct risk to the crew. < / P > < p > flight controllers woke up the astronauts and astronauts late on Monday night to get rid of the leakage that & quot; seemed to be getting bigger and bigger. The crew used an ultrasonic leak detector to collect data for analysis. NASA said the larger leakage should be attributed to temporary temperature changes on the space station, and the overall leakage rate remained unchanged. Global Tech