March 21 in Universe History: Space Missions, Satellites and Exploration

2000

On 21 March 2000, during vibration testing at JPL, the High Energy Solar Spectroscopic Imager spacecraft was substantially damaged after a test device delivered about 20 g, far above intended levels, cracking two solar arrays and harming the structure. The mishap prompted an independent failure review and delayed the solar-flare physics mission’s launch.

2001

On 21 March 2001, Space Shuttle Discovery landed at Kennedy after STS-102, completing the first Expedition crew rotation for the International Space Station and returning Expedition 1 to Earth. The mission also delivered and later returned the Leonardo multipurpose logistics module with supplies and racks, advancing early station assembly, joint operations, and orbital logistics procedures.

2012

On 21 March 2012, Cassini’s Imaging Science Subsystem spent about 12 hours searching for possible small satellites near the stability region 60 degrees ahead of Titan in its orbit around Saturn, at the L4 Lagrange point. The campaign aimed to detect new moons or refine faint-object orbits, improving hazard assessment and observation planning during continuing mission operations at Saturn.