A SpaceX Falcon 9 rocket launched Northrop Grumman’s 21st Cygnus mission (NG-21) carrying more than 8,000 pounds of supplies to the International Space Station from Space Launch Complex 40 (SLC-40) at Cape Canaveral Space Force Station at 11:02 a.m. on 4 August 2024. Aboard the Cygnus spacecraft are tests of water recovery technology, a process to produce stem cells in microgravity, studies of the effects of spaceflight on microorganism DNA, liver tissue growth, and live science demonstrations for students.

Following stage separation, the Falcon 9 first stage booster landed on Landing Zone 1 (LZ-1) at Cape Canaveral Space Force Station.

This is the tenth flight of the first stage booster supporting this mission, which previously launched Ax-2, Euclid, Ax-3, CRS-30, SES ASTRA 1P, and four Starlink missions.