Washington, Aug 21 (IANS): A small air leak on the International Space Station (ISS) is still within segment specifications and presents no immediate danger to the crew or the orbiting laboratory, NASA has said.

However, teams are working on a plan to isolate, identify, and potentially repair the source of the leak, NASA said in a blog post on Thursday.

The space station is actually not designed to be airtight.

The orbiting laboratory's atmosphere is maintained at pressure comfortable for the crew members, and a tiny bit of that air leaks over time, requiring routine repressurisation from nitrogen tanks delivered on cargo resupply missions.

In September last year, NASA and its international partners first saw indications of a slight increase above the standard cabin air leak rate.

Due to routine station operations like spacewalks and spacecraft arrivals and departures, it took time to gather enough data to characterise those measurements.

NASA said that all the space station hatches will be closed this weekend so mission controllers can carefully monitor the air pressure on the space station.

"The test presents no safety concern for the crew. The test should determine which module is experiencing a higher-than-normal leak rate," NASA said.

"The US and Russian specialists expect preliminary results should be available for review by the end of next week," it added.

The three Expedition 63 crew members living aboard the International Space Station will spend the weekend inside the orbiting lab's Russian segment.

Commander Chris Cassidy and his crewmates Ivan Vagner and Anatoly Ivanishin will stay in the Zvezda service module from Friday night till Monday morning.

Cassidy, Vagner and Ivanishin also will have access to the Poisk mini-research module and their Soyuz MS-16 crew ship for the duration of their stay, NASA said.