SpaceX is set to launch a Falcon 9 rocket carrying Northrop Grumman's Cygnus spacecraft on the NG-21 resupply mission to the International Space Station (ISS). The launch, scheduled for Sunday, August 4 at 11:02 a.m. EDT, will deliver over 8,200 pounds of supplies and scientific experiments, including investigations into water recovery systems and DNA repair in microgravity. Weather conditions are a concern, with only a 50% chance of favorable conditions due to Tropical Depression Four. If the launch is delayed, the next attempt will be on Monday. The Cygnus spacecraft, named S.S. Richard, will contribute to ongoing research and resupply efforts on the ISS.