Russian cargo ship docks at International Space Station

The cargo ship automatically attached itself to the Pirs docking compartment on the Russian segment at 5:35 a.m. ET.

"The Progress 74 spacecraft is carrying almost three tons of food, fuel and supplies for the Expedition 61 crew aboard the station," according to NASA. "Progress will arrive after making 49 orbits of Earth in three days since its launch Friday."

The Russian cargo ship joined the space station as the two craft sailed over the Yellow Sea, east of Shanghai, at an altitude of 260 miles.

Russian cosmonauts Alexander Skvortskov and Oleg Skripochka oversaw -- but did not need to intervene in -- the automatic docking.

The space station's crew has lots of unpacking to do, as another vessel, SpaceX's Dragon cargo ship, arrived on Sunday morning, bringing with it 2.5 tons of supplies and science gear.

Both dockings were broadcast live on NASA TV.

A third cargo vessel, the U.S. Cygnus spacecraft built by Northrop Grumman, remains attached to to the space station, having arrived in early November. Two Soyuz crew capsules, waiting to ferry astronauts home, are also docked at the space station.

NASA considers the space station an important bridge to the Artemis program, the effort to return astronauts to the surface of the moon.

"As the only place for conducting long-duration research on how living in microgravity affects living organisms as well as testing technologies to allow humans to work at the Moon, the space station serves as a unique asset in the effort establish a sustainable presence at the Moon and prepare for missions to Mars," NASA wrote in an update.

At 9 a.m. ET, NASA Administrator Jim Bridenstein will provide a live update to the agency's Artemis program progress at NASA's Michoud Assembly Facility in New Orleans.