Q&A with Mark Sirangelo, leader of Sierra Nevada Space Systems

A Falcon 9 rocket is again standing upright on launch pad 39A at NASA’s Kennedy Space Center in Florida after ground teams lowered the booster Friday to swap out mice heading to the International Space Station for medical experiments.

Closing out an automated 18-hour rendezvous, a SpaceX Dragon cargo ship loaded with 7,000 pounds of supplies and equipment, including two add-on roll-out solar blankets, caught up with the International Space Station early Tuesday and moved in for a problem-free docking.

SpaceX’s Falcon 9 rocket took off from Cape Canaveral on Friday afternoon, sending a Dragon cargo freighter on the way to the International Space Station as the launcher’s first stage booster returned to Earth aboard a floating platform.