Live coverage: Soyuz crew returns to Earth

During a fourth spacewalk Saturday to wrap up repairs of the coolant system in a $2 billion cosmic ray detector, Italian astronaut Luca Parmitano and Drew Morgan discovered a leak in one of eight coolant lines that were spliced into a new pump module during three earlier excursions. But Parmitano was able to tighten a fitting on the line and the astronauts were able to complete the repair work, setting the stage for the instrument to resume science operations.

A Soyuz spacecraft carrying a Russian commander, a NASA flight engineer and a Japanese physician-astronaut docked with the International Space Station early Tuesday, capping a smooth two-day rendezvous to boost the lab’s crew back to six.

It is a rocket like no other, a vehicle with a single solid-fuel booster mounted to its side, that will launch NASA’s OSIRIS-REx probe next month to bring back a sample of Asteroid Bennu.