Snapshots from Atlas 5 launch

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.

Follow the Atlas 5 rocket’s ascent into orbit from Cape Canaveral’s Complex 41 launch pad with the Orbital ATK Cygnus resupply ship for the International Space Station. Launch is scheduled for Thursday at 5:55 p.m. EST (2255 GMT).

SpaceX raised a 215-foot-tall Falcon 9 rocket on pad 39A at NASA’s Kennedy Space Center in Florida this week, shortly after the launcher rolled out of the company’s hangar with a Crew Dragon spaceship to ferry four astronauts to the International Space Station.