The international space station received its ninth Russian supply craft Sunday as the unmanned freighter successfully docked to the rear end of the complex under its own control.

After a four-day trek to the station -- a couple days longer than usual to allow an engineering test to be performed on the craft's KURS automatic rendezvous system -- began on Wednesday with liftoff from the Baikonur Cosmodrome in Kazakhstan.

Sunday's link up occurred 245 miles over Central Asia at 1701 GMT (1:01 p.m. EDT), a few minutes ahead of the advertised time. A short time later, hooks and latches closed between the freighter and Zvezda service module docking port, forming an airtight seal.

Known as Progress 9P in the space station assembly sequence, the Russian-made Progress M1-9 vessel is loaded with the usual assortment of fresh supplies, food, clothing, experiments and spare parts for the outpost's current crew, plus the visiting Soyuz "taxi crew" due to arrive for a week's stay at the end of October and the next long-duration resident crew in mid-November.

In addition, fuel carried aboard the Progress will be transferred into the Russian segment of the station for use by maneuvering thrusters.

The Progress is also carrying census forms to be filled out by Expedition 5 commander Valery Korzun and flight engineer Sergei Treschev. The two cosmonauts and NASA Science Officer Peggy Whitson were spending their 114th day aboard the station Sunday.

Expedition 5 will be replaced by the Expedition 6 crew -- commander Ken Bowersox and flight engineers Nikolai Budarin and Don Pettit -- after a five-and-a-half month voyage. The new crew will launch aboard shuttle Endeavour on November 10 and Expedition 5 will ride the U.S. orbiter home.

The current Russian Soyuz lifeboat capsule, which has a six-month certified life in space, is slated to be swapped out by the "taxi crew" of commander Sergei Zalyotin and flight engineer Frank De Winne of the European Space Agency. The two men will launch aboard a fresh Soyuz on October 28, docking to the station two days later. After spending about a week aboard the complex, they will ride the old Soyuz back to Earth.

Meanwhile, officials said the Progress 8P craft, which arrived at the ISS in June and undocked on Tuesday to make room for the new Progress, remains in orbit a safe distance away from the station, spending another 10 days aloft to enable Russian flight controllers to document smog and smoke over northeastern Russia through its cameras.