WASHINGTON — A Space Exploration Technologies Corp. Dragon spacecraft carrying more than 2 metric tons of cargo arrived at the international space station early Sept. 23.

The space station’s robotic arm grappled the Dragon spacecraft slightly ahead of schedule at 6:52 am EDT. The arm then moved the spacecraft into position, berthing it to a port on the station’s Harmony module at 9:21 am EDT.

A SpaceX Falcon 9 v1.1 rocket launched the Dragon Sept. 21 on the fourth of 12 missions that are part of the company’s Commercial Resupply Services contract with NASA. The spacecraft carried 2,216 kilograms of cargo for the station, including crew supplies, ISS hardware and experiments.

The Dragon’s payload includes a variety of experiments demonstrating the range of research planned for the station by NASA and the Center for the Advancement of Science in Space, the nonprofit organization that manages the national laboratory elements of the ISS.

One experiment features 20 mice that will live on the station for a month to study the effects of long-duration microgravity on them. Another experiment is the first 3-D printer flown in space, developed by Made in Space Inc. The ISS-RapidScat sensor, carried in the Dragon’s unpressurized cargo section, will be mounted on the station’s exterior to monitor wind conditions over Earth’s oceans.

Dragon will remain at the ISS for about four weeks before returning to Earth. NASA plans to return nearly 1,500 kilograms of cargo from the station on the Dragon, including experiments and station hardware.

Follow Jeff on Twitter: @jeff_foust

One experiment features 20 mice that will live on the station for a month to study the effects of long-duration microgravity on them. Another experiment is the first 3-D printer flown in space, developed by Made in Space Inc. The ISS-RapidScat sensor, carried in the Dragon’s unpressurized cargo section, will be mounted on the station’s exterior to monitor wind conditions over Earth’s oceans.

Dragon will remain at the ISS for about four weeks before returning to Earth. NASA plans to return nearly 1,500 kilograms of cargo from the station on the Dragon, including experiments and station hardware.

Follow Jeff on Twitter: @jeff_foust