Roscosmos said the hatch between the station and the Progress MS-21 had been locked so the loss of pressure didn’t affect the orbiting outpost.
“The temperature and pressure on board the station are within norms and there is no danger to health and safety of the crew,” it said in a statement.
The space corporation didn’t say what may have caused the cargo ship to lose pressure.
Roscosmos noted that the cargo ship had already been loaded with waste prior to its scheduled disposal. The craft is set to be undocked from the station and deorbit to burn in the atmosphere on Feb. 18.
The announcement came shortly after a new Russian cargo ship docked smoothly at the station on Saturday. The Progress MS-22 delivered almost three tons of food, water and fuel along with scientific equipment for the crew.
Roscosmos said that the loss of pressure in the Progress MS-21 didn’t affect the docking of the new cargo ship and “will have no impact on the future station program.”
The depressurization of the cargo craft follows an incident in December with the Soyuz crew capsule, which was hit by a tiny meteoroid that left a small hole in the exterior radiator and sent coolant spewing into space.
Russian Cosmonauts Sergey Prokopyev and Dmitri Petelin, and NASA astronaut Frank Rubio were supposed to use the capsule to return to Earth in March, but Russian space officials decided that higher temperatures resulting from the coolant leak could make it dangerous to use.
They decided to launch a new Soyuz capsule on Feb. 20 so the crew have a lifeboat in the event of an emergency. But since it will travel in automatic mode to expedite the launch, a replacement crew will now have to wait until late summer or fall when another capsule is ready. It means that Prokopyev, Petelin and Rubio will have to stay several extra months at the station, possibly pushing their mission to close to a year.
NASA took part in all the discussions and agreed with the plan.
Besides Prokopyev, Petelin and Rubio, the space station is home to NASA astronauts Nicole Mann and Josh Cassada; Russian Anna Kikina; and Japan’s Koichi Wakata. The four rode up on a SpaceX capsule last October.