The ISS Progress 21 is filled with 2.5 tons of food, fuel and personal items for the station's Expedition 13 crew.
Commander Pavel Vinogradov and Flight Engineer Jeff Williams will open the hatch to the supply ship once leak checks are completed later today. The crew will begin unloading items Thursday.
Automatically guided by its computers, the Progress docked to the aft port of Zvezda at 1:41 p.m. EDT as the spacecraft and the station sailed 219 miles above Greece. The Progress was launched Monday from the Baikonur Cosmodrome in Kazakhstan.
The supplies include food, fuel, oxygen and air, clothing, experiment hardware and spare parts, as well as personal items from the crew's families. The new Progress joins an older Progress supply ship that arrived at the station's Pirs Docking Compartment just before Christmas. Progress 20 will remain docked until mid-June. It will be used to stow trash, and its supply of oxygen will help replenish the station's atmosphere.
ISS Progress 21 holds 1,918 pounds of propellant for the Russian thrusters, 103 pounds of oxygen and air in tanks as a backup supply for the oxygen generated by the Russian Elektron system and 661 pounds of water to augment the supplies already on board. The spacecraft's cargo also includes more than 2,300 pounds of spare parts, experiment hardware and life support components.