Video: Liftoff of Atlas 5 on space station cargo mission

Towering more than 30 stories tall, the mobile gantry structure at the Delta 4-Heavy rocket’s launch pad at Cape Canaveral was wheeled into position for liftoff of the triple-core launcher Thursday with a classified payload for the National Reconnaissance Office.

A Vega rocket is set to deliver two satellites into similar but distinct orbits for the Italian military and the French and Israeli space agencies. Follow key events scheduled during the launch with this timeline.

Struggling with balky electrical connectors, spacewalker Mike Hopkins managed to plug in and secure three of four thick power and data cables Saturday that are needed by a European experiment platform, leaving one cable for additional troubleshooting.