Russia's space agency is considering sending an empty spaceship to the International Space Station to bring home three crew members early after their capsule began leaking.
It's not clear how the external radiator on the spaceship sustained a small puncture.
There was no impact of a meteorite.
Two cosmonauts were preparing for a spacewalk.
The three crew members will be brought back to Earth in different ways.
The most likely way to get them is to send another spaceship.
It's not likely that they'll be sent home in a capsule without most of the crew's cooling equipment.
Russian cosmonauts Dmitry Petelin and Sergey Prokopyev were among the people who were flown to the station.
Nasa TV captured dramatic images of white particles streaming out of the capsule.
The most likely time to launch another Soyuz is late February. The crew was supposed to come back in March.
No one of the crew is in danger, according to NASA.
The open hatch of the space station allows air flow to be allowed through the capsule.
The International Space Station is about 400 km away from the Earth.
The station is used by astronauts to carry out tests and research.