Dragon has docked at the space station Sunday morning at 4:56 am Alaska Time. The capsule is scheduled to spend the next 22 days docked to the Harmony module of the spacecraft.

Expedition 34 commander Kevin Ford and Flight Engineer Tom Marshburn, using the station’s robotic arm, gained purchase of the capsule, guided it into place and attached it to the module.

While the trip to the station, and the docking was eagerly awaited because of cargo to the station, such as equipment, food and other supplies, it is the return trip that many others look forward to.

On the return trip, the capsule will ferry back twice as much cargo as it transported to the station. Aboard the trip back will be investigation samples that will demonstrate how life in microgravity affects the growth of plant seedlings, changes to the human body, the behavior of semiconductors and detergents, and more.

Projects sent up by scientists from Canada, France, Japan and the United States as well as several high school students are expecting projects ranging from plants to experiments with liquid crystals to return with the capsule on March 25th.

Although many rocket assisted capsule are able to bring cargo and supplies to the station, only Soyuz and the Dragon capsules are designed to make a return trip. For the United States, this makes the Dragon a mode of return transport that increases the station’s science return, which is an important capability that allows the ability to retrieve samples for analysis on the ground back on earth.