Ride home for team aboard Space Station is leaking; spacewalk canceled

NASA Astronaut Frank Rubio, Prokopyev and Petelin arrived at the International Space Station in September via the Soyuz spacecraft, which is also their ride home. Engineers in Moscow and Houston continue to determine the next steps for the leaking spacecraft.

Russia's Soyuz spacecraft docked at the International Space Station is spewing coolant into space, causing mission managers to cancel a planned cosmonaut spacewalk, according to NASA.

As Roscosmos cosmonauts Sergey Prokopyev and Dmitri Petelin were preparing for their upcoming spacewalk Thursday outside the space station, ground teams discovered a substance leaking from the Soyuz spacecraft docked to the Russian Rassvet module.


According to NASA, the substance leaking was later identified as coolant coming from the aft, or rear, of the Soyuz. The space agency said the suspected leak source is the Soyuz external radiator cooling loop, which helps keep the spacecraft at the right operating temperature. 

NASA and Roscosmos continue to monitor the Soyuz spacecraft temperatures. As of the latest update, the spacecraft is within acceptable temperature limits, according to NASA.

The Soyuz and SpaceX Crew Dragon spacecraft docked at the ISS are the only way astronauts can get back to Earth. 

NASA Astronaut Frank Rubio, Prokopyev and Petelin arrived at the ISS in September onboard the Soyuz. The Russian spacecraft is also their ride home. 

NASA astronauts Nicole Mann and Josh Cassada, Japanese Space Agency (JAXA) astronaut Koichi Wakata and Roscosmos cosmonaut Anna Kikina arrived at the ISS via SpaceX's Crew Dragon spacecraft in early October. The Crew Dragon has four seats. 

"The crew members aboard the space station are safe, and were not in any danger during the leak," NASA wrote in a blog post.

The leak was first discovered around 7:45 p.m. EST on Wednesday when ground teams were alerted to a low-pressure warning in one of the Soyuz cooling loops.


"We noticed a visible stream of flakes coming from the aft of the Soyuz near the instrumentation and propulsion module that was indicative of a leak," NASA Public Affairs commentator Rob Navias said. 

After the leak was discovered, the spacewalk was canceled, and ground teams in Moscow and Houston have been working together to determine the next steps to address the leak. The cosmonauts were scheduled to install a radiator using the European Space Agency's robotic arm. That spacewalk has been postponed indefinitely.

The astronauts used a camera on the ESA's robotic arm to further examine the leak, and plans are being made to use the station's Canadarm2 robotic arm to inspect the Soyuz.

NASA still plans to move forward with a spacewalk on Monday.

Two NASA astronauts will continue the work that started earlier this month by installing rollout solar arrays outside the space station to upgrade the station's power grid.