A little while ago, Northrop Grumman’s Cygnus spacecraft blasted off atop a SpaceX Falcon 9 rocket from the Kennedy Space Center on its NG-21 or CRS NG-21 mission. After about 15 minutes, it successfully separated from the rocket’s last stage and set on its course. This is the second of at least three resupply missions to the International Space Station with various payloads launched using the Falcon 9 rocket while waiting for the new version of Northrop Grumman’s Antares rocket to be ready.