Early Saturday morning the Dragon cargo spacecraft that’s been attached to the International Space Station since Dec. 17 is expected to be released and sent back to Earth.

The plan was to have the flight controllers on the ISS use the robotic arm of the station to move the Dragon into place on Friday so that come Saturday morning, a ground-controlled crew could release the craft at the perfect time to send it back to Earth, NASA said in a release.

Coverage of the release will start at 4:30 a.m. EST Saturday and the craft is scheduled for a 5 a.m. release. Less than four hours later, at 10:26 a.m. EST, the craft, full of experiments, is expected to splash into the Pacific Ocean. There “recovery forces” are expected to pull the Dragon from the water and taken it by ship to Long Beach, California. Once on the mainland, some of the materials inside will be removed and sent to NASA right away while others are will be prepped and then sent to the SpaceX facility in Texas, NASA said.

The Dragon will be filled with 4,100 pounds of cargo including samples for human research, educational activities, physical science and other experiments when it splashes down, according to NASA.

Some of the experiments on board include plant samples that were used to study how plants grow in low oxygen environments and how they react to the stress caused by that environment. Another experiment involved live mice on the station that will hopefully survive the trip back to Earth. While in space the mice, part of Rodent Research-6, were used to study a drug administered to potentially counteract the muscle loss that occurs in zero gravity environments, according to NASA. Some mice were treated with placebo while others were administered the drug continuously through a nanochannel chip, said NASA.

Watch the Dragon craft release from the International Space Station: