SpaceX’s Dragon cargo capsule safely splashed down off the coast of Florida at 1:39 p.m. EDT (1839 GMT) today (Dec. 17), following its departure from the International Space Station (ISS) a day earlier. This marked the return of CRS-31, which carried thousands of pounds of equipment and experimental samples from ongoing microgravity research aboard the station.

The Dragon spacecraft remains unique as the only ISS cargo vehicle capable of returning scientific materials and equipment intact to Earth. In contrast, the other active cargo freighters-Northrop Grumman’s Cygnus and Russia’s Progress-are designed to burn up during atmospheric reentry, along with any waste materials they carry from the station.

CRS-31 initially launched on Nov. 4 from NASA’s Kennedy Space Center (KSC) in Florida, atop a SpaceX Falcon 9 rocket. A day later, the capsule docked with the ISS, delivering approximately 6,000 pounds (2,700 kilograms) of supplies and scientific materials for the Expedition 71 crew. This included fresh food, maintenance tools, and personal items to sustain the astronauts aboard.

NASA astronauts Butch Wilmore and Suni Williams, who arrived on the ISS during Boeing’s first crewed Starliner flight in June, were among those benefiting from CRS-31’s delivery. Initially scheduled for a short eight-day mission, complications with the Starliner extended their stay to eight months. NASA later decided to return Starliner to Earth without a crew, leaving Wilmore and Williams set to return home in February aboard SpaceX’s Crew-9 mission, which arrived in September.

During their extended stay, Wilmore and Williams adapted to the station’s challenges, including leaving behind personal items like clothes to accommodate urgent cargo. Subsequent supply missions by Cygnus and Progress brought relief, restocking essentials such as shirts and toothbrushes, along with crew-favorite treats like fresh fruits and vegetables.

Upon splashdown, NASA teams moved quickly to recover the Dragon capsule. Scientific experiments requiring immediate attention after reentry will be transported to the Systems Processing Facility at KSC. There, researchers can resume work in the post-microgravity environment. Originally planned to undock on Dec. 6, CRS-31’s departure was delayed multiple times due to unfavorable weather in the splashdown area, underscoring the challenges of coordinating safe cargo returns from space.