After almost a month spent attached to the International Space Station, SpaceX's Dragon capsule has successfully returned to Earth. The podule, laden with science experiments including the bodies of 40 mice, is now on its way to NASA via ship.

The capsule, which made a belated berthing with the ISS on February 23 thanks to a computer error, was unhooked from the ISS at 0511 ET (0911 UTC) on Sunday by European Space Agency astronaut Thomas Pesquet using the station's robotic arm. After a series of maneuvering thrusts, the capsule orientated itself and began a reentry burn.

The podule had no problems making it down through the atmosphere, although it looks understandably a little scorched from air compression. It splashed down at 1052 ET (1452 UTC) around 200 miles off the coast southwest of Long Beach, California. A retrieval ship was ready and made the pickup safely.

Dragon is headed to port for a cargo handover to @NASA. https://t.co/C3Pix9DGAg pic.twitter.com/wPdFTlsNsP — SpaceX (@SpaceX) March 19, 2017

The capsule contains a wealth of science experiment equipment and test results, and these are now on their way to NASA for unpacking. The findings could be key to ensuring that mankind can get out and about safely in the Solar System, as well as helping us understand life here on the home planet.

For example, the Microgravity Expanded Stem Cells experiment should provide important information on how human stem cells fare in microgravity. Growing stem cells is tough in laboratory conditions, and the experiment is designed to see if it's faster to do so in space.

The experiment will be useful for long-term space missions, since it'll show how cancer cells may grow and spread due to radiation issues. But it's also hoped that if stem cells are easier to duplicate in space, orbital facilities could keep Earth supplied too.

The capsule also contains the Tissue Regeneration-Bone Defect experiment, which tests how well wounds and bones heal in space. Getting to another planet is going to cause injury occasionally, and the boffins at NASA want to see if low or no gravity is going to cause issues with our healing processes.

To investigate this, scientists broke the legs of 40 mice, and used three different treatment methods to heal the breaks. A week after the operation, the little blighters were blasted up to the space station, spent three weeks being monitored by astronauts before being euthanized, and sent back to Earth in the Dragon podule on Sunday for comparison with the control group on the ground.

(The creatures had to die to stop them continuing to heal on the return trip – they had to die at the same time – and to avoid putting them through the stress of reentry, we're told.)

The experiments also covered how machinery can function in space. The Materials on International Space Station experiment uses SpaceCube, a field programmable gate array developed at NASA Goddard that has been designed to withstand the higher radiation levels in space. Scientists will be checking the data it processed to look for errors.

SpaceX has another flight set for this month, but it won't be going to the ISS. Instead the company is going to try the first flight of a reused Falcon 9 rocket to deliver a communications satellite into orbit. ®