Today (June 24), NASA canceled a spacewalk on the International Space Station due to a spacesuit coolant leak in the hatch.

NASA astronauts Tracy Caldwell Dyson and Mike Barratt were ordered by flight control to cancel their planned 6.5-hour spacewalk outside the International Space Station (ISS) at 8:52 a.m. ET (12:52 GMT). The pair had switched to internal power with their suits at 8:46 a.m. (12:46 GMT), meaning the spacewalk had technically begun. Following the cancellation, the astronauts officially ended the spacewalk by opening the hatch of the ISS at 09:51 ET (13:51 GMT).

During a live NASA television broadcast, they reported “water literally everywhere” as they switched their suits to internal power to prepare for extravehicular activities. He said the leak was caused by the service and cooling (SCU) hose in Dyson’s suit. Although the situation was serious, the astronauts were not in any danger from the leak.

NASA released a brief official statement following the cancellation, adding that more information would be posted on the agency’s ISS blog. Speaking to NASA Television, officials added that they called for the cancellation as a precaution because it was unclear how much water remained in Dyson’s suit after the leak.

“I saw ice crystals coming out of there and then ice forming like a snow machine in the harbor at SCU,” Dyson told Mission Control. The SCU is designed to connect to the ISS’ airlock chamber while the astronauts are in the hatch preparing the final disconnection stages for the EVA. They were still inside the hatch and the outer door was open when the leak occurred, but they closed the door a few seconds after the spacewalk was completed. “It was a pretty spectacular snowstorm,” astronaut Butch Wilmore said during NASA’s livestream.

This is the second time this spacewalk has been postponed, after a June 13 trial with another group of astronauts (Matt Dominik and Tracy Dyson) was postponed due to Matt Dominik’s “spacesuit discomfort” issue. A spacewalk is also planned for July 2, but it is unclear whether this will happen under these conditions.

The total duration of the spacewalk was 31 minutes, based on the time between switching the suits to internal power and repressurizing the crew’s airlock. This brings Tracey Dyson’s total spacewalk time to 23 hours 20 minutes for four spacewalks and Mike Barratt’s total time to 5 hours 37 minutes for three spacewalks.