An artist's concept of Progress 251/1P nearing the International Space Station. Photo: NASA TV/Spaceflight Now

A Russian Soyuz rocket boosted an unmanned Progress supply craft into orbit today carrying critical equipment and fuel to the international space station along with supplies for its first full-time crew.

The mission began at 2:26:42 p.m. EDT (1826:42 GMT) with an on-time liftoff from the Baikonur Cosmodrome in Kazakhstan. NASA officials said the Progress was delivered into a 233 by 182 km orbit and the ship's antennas and solar arrays had been deployed.

If all goes well, the automated docking sequence will end Tuesday at 4:14 p.m. EDT (2014 GMT) when the Progress 251 vehicle docks with the aft port of the station's new Zvezda command module.

See our timeline of events planned for the Progress craft from launch through docking.

The long-delayed Zvezda module, launched July 12 atop a Russian Proton rocket, successfully docked with the station July 25, clearing the way for more than 15 assembly and outfitting flights over the next 12 months.

The Progress mission launched today, known as station assembly flight 1P, is the first in that series, clearing the way in turn for launch of the shuttle Atlantis on Sept. 8. The shuttle's U.S.-Russian crew will unload the Progress, transfer other supplies from the orbiter to the station and activate various systems for the lab's first full-time crew.

If all goes well, commander William Shepherd, Yuri Gidzenko and Sergei Krikalev will blast off around Oct. 30 to begin a planned four-month stay aboard the international space station.

"When the first crew arrives they're going to take delivery of an infant station," said operations manager James Van Laak. "It will not be fully outfitted, not all the systems will be fully operational and they will have quite a bit of work to do over the first few weeks getting those systems activated."

Much of the equipment the first crew will use is packed aboard the Progress 251 vehicle launched today, including a carbon dioxide removal system, components for Zvezda's oxygen generation system, parts for the station's toilet, two IBM ThinkPad computers and other electrical gear.

The Progress vehicle also carries clothing, tools, brackets, myriad nuts and bolts, food preparation equipment, air purification systems, television and communications gear and components of other life support systems.

One of the primary goal of Atlantis's mission in September is to offload the Progress 251 vehicle to make way for a second Progress later this fall. That Progress will be docked to a different port to free Zvezda's aft port for Shepherd's crew.

"We'll be unloading the Progress vehicle at the back of the Zvezda spacecraft and bringing those cargoes in, prepositioning many of them, installing some of them in place, in an effort to configure the vehicle for the arrival of the crew," said Phil Engelauf, lead flight director for Atlantis's mission.

An illustration of a Progress cargo freighter.

"The Zvezda was launched with many of the critical life support systems offloaded in order to bring the weight of the vehicle down for launch," he explained. "And since there was not going to be a crew on board initially, the emphasis was placed on installing hardware in support of the spacecraft as a free flier."

Now that Zvezda is in place, "we will now be outfitting primarily with the crew support items, life support systems, internal audio communications systems and so forth," Engelauf said. "In addition, the Progress is carrying a significant amount of fuel that will be transferred to the station."

The space station currently consists of three modules. On one end is NASA's Unity node, a six-hatch module that will serve as a gateway to future station components. The Russian-built NASA-financed Zarya module is attached to Unity and Zvezda is attached to Zarya's aft docking port. Progress 251 will dock with the other end of the Zvezda module using Russian's automated KURS docking system.

Russian flight controllers plan to re-orient the space station into the preferred docking orientation Tuesday afternoon, completing the maneuver by 1:42 p.m. EDT (1742 GMT). The Progress 1P automated docking procedure will begin one minute later.

After a half-dozen rendezvous rocket firings, the Progress 1P vehicle will begin station keeping a few hundred feet from the station around 3:50 p.m. (1950 GMT). Then, after coming in contact with Russian ground stations, the Progress will resume its approach around 4:06 p.m., docking nine minutes later.

The linkup will occur one minute before orbital sunrise with the space station in line-of-sight contact with Russian ground stations and NASA's western Tracking and Data Relay Satellite.