NASA flight controllers inHouston also watched over the event.

Progress was launchedSunday from the BaikonurCosmodrome in Kazakhstan flying atop a three-stage Russian Soyuz rocket.

Although Russia used theProgressvehicles for more than two decades to resupply its orbital outposts-- including the Mir space station -- this is the first such mission tothe ISS.

Moreover, this Progress modelis considered an improvement over its earlier counterparts, Vladimir Solovyov,a senior Russian flight director and former cosmonaut, told SPACE.comafter the docking.

"This Progress is the thirdin a row of the same type of spacecraft," Solovyov said. "Its two predecessorshave already flown to Mir."

"I would say that this typeof Progress is certainly more 'intellectual.' It has better developed softwareand computers which assured a more careful, smooth and precise dockingof spacecraft with the station."

The U.S. space shuttle hasbeen used in the past to deliver equipment and supplies to the ISS, aswell as boost the outpost's orbital altitude.

However, Progress is theonly vehicle which is able to refuel the station's propellant tanks andwill also be used to help raise the station's orbit, which slowly degradesdue to the drag from the thin layer of air existing at this altitude.

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The spacecraft also carrieda supply of dry cargo, including housekeeping items and life-support equipmentfor future crews that will visit ISS. These supplies will remain storedaboard Progress until shuttle Atlantis visits the station during a missionscheduled for early September.

This frame from a NASA animationshows a Progress module (far right) docked to the International Space Station'sZvezda service module.

Progress docked to the stationat the rear port of the Zvezda service module, the newest Russian elementof the three-segment spacecraft. Zvezdadocked with the station on July 26. The module's propulsion systemis currently used to maintain attitude of the entire outpost.

Other elements of the embryonicstation include the Russian-built and U.S.-financed Zarya control moduleand NASA's Unity module. They are attached to Zvezda at its front dockingport. With the arrival of the Progress M1-3, the weight of the ISS in orbithas grown to 67 tons, compared to around 40 tons before its docking withZvezda.

Numerous other componentsfor the ISS will be launched during the next five years as part of a cooperativeeffort between the United States, Russia, the European Space Agency, Japan,Canada, Brazil and Ukraine.

Another Progress missionto the ISS is scheduled for liftoff on September 21, however Solovyov saidthat Russian space officials would like to wait until after the first crewis launched to the station before sending another Progress up.

Having a crew on board wouldimprove the odds of a successful mission, Solovyov said.