SpaceX Dragon cargo splashes down successfully off the Florida coast

On Wednesday, NASA announced that the upgraded SpaceX Dragon cargo spacecraft successfully splashdown at 8:26 PM EST west of Tampa, Florida. The successful splashdown marked the ending of the company's 21st contracted cargo resupply mission to the ISS. The spacecraft carried over 4400 pounds of scientific experiments and other cargo back to Earth.

Upgrades to this particular Dragon cargo spacecraft included doubled powered locker availability compared to previous capsules allowing for a significant increase in the amount of research experiments delivered back to Earth for scientists. The mission was also notable because of the very quick turnaround in getting experiments from the capsule to scientists waiting on the ground in Florida to begin their research.

NASA says that some scientists had their research returned in 4 to 9 hours after splashdown. There were several experiments aboard the spacecraft, including Cardinal Heart. That particular experiment investigated how microgravity causes changes in the workload and shape of the human heart. NASA says it still unknown if those changes become permanent if a person lives more than a year in space.

Space Organogenesis was another experiment returned aboard the spacecraft and was an investigation by JAXA to demonstrate the growth of 3D organ buds from human stem cells to analyze changes in gene expression in microgravity. One of the returned experiments was the sextant used in the Sextant Navigation experiment aboard the ISS. Mariners used the sextant for navigation for centuries before modern navigation techniques were developed.

Rodent Research-23 was also among the returned experiments. It studied the function of arteries, veins, and lymphatic structures in the eye and changes in the retina of mice before and after spaceflight. Rodents were returned to Earth in that study. A number of additional experiments were returned in the mission.