It has been traced to a small hole in a capsule that was used to deliver a new crew to the laboratory 400km (250 miles) above the Earth in June. All station systems are reported to be stable and the crew is planning to return to its regular schedule of work on Friday.
A NASA spokesman said it was too early to speculate on whether the three might have to return to Earth early if the leak can not be stopped. At one point, NASA astronaut Drew Feustel, who serves as the space station's commander, counseled caution.
The astronauts were asleep at the time, but when they rose for their day's work on Wednesday they were instructed to search for the leak.
The urgent filling of the sealant insisted the Russian space Agency, while NASA first wanted to test on the Ground the implications of this decision.
Now flight controllers are monitoring the cabin pressure while coming up with a better and long-term solution for the leak. Flight controllers at NASA Mission Control Center in Houston worked with their Russian counterparts to enable the repairs.
The expiration gathers supplementary pressure on the National Aeronautics and Space Administration (NASA) to renew its capacity to shuttle USA crew members back and forth to the orbiting lab. NASA is negotiating with Boeing Co. and SpaceX to develop new vehicles to transport astronauts, but the work has been troubled by relentless delays. "The lives and the health of the crew members are not threatened, and the spacecraft will most likely be preserved as a result of using a fix toolkit for localizing this leak".
Even with the scary thought the space crew could have run out of oxygen, NASA and Russian space officials have stressed all six astronauts on the ISS were and are in no danger.
NASA also stated that the hole was found in the upper spherical section of the capsule, a part that doesn't return to Earth, which means good news for the astronauts that count on the capsule to get back home.