Mystery Surrounds Empty Crew Capsule's Landing on Earth.

A Soyuz spacecraft returned to Earth without any crew after suffering a significant coolant leak while docked at the International Space Station (ISS) last December. The capsule was deemed too risky to use to bring home three crewmembers in case its interior heated up to a dangerous level as it entered Earth’s atmosphere at high speed. NASA’s Russian counterpart, Roscosmos, which operates the Soyuz spacecraft, was still keen to bring it to Earth as they’d like to examine it to try to determine what exactly caused the leak. The current thinking is that the capsule may have been struck by a micrometeoroid while docked at the station.