Tune in live starting at 15:45 UTC, Sun., Dec. 6 as the 21st SpaceX cargo resupply mission to the International Space Station lifts off from Launch Complex 39A at NASA’s Kennedy Space Center. Launch is targeted at 16:17 UTC. The targeted date has changed due to poor weather conditions on Sat., Dec. 5 in the recovery area. This will be the first flight of the upgraded cargo version of the Dragon 2 spacecraft. On board are over 250 science investigations, as well as the Nanoracks Bishop Airlock, set to be attached to the station’s Tranquility module. This first commercially funded space station airlock will increase the capacity for external space research at the space station.