NASA officials say expected rain showers may delay Thursday's launch of the space shuttle Atlantis whose mission is to deliver a new science lab to the International Space Station. In Miami, VOA's Brian Wagner reports.

NASA engineers and astronauts are eager to begin the Atlantis mission, which was postponed about two months because of equipment problems on the shuttle's external tanks.

Technicians resolved that problem by replacing a faulty connection in the fuel system on the liquid hydrogen tanks.

Now officials say they are concerned about a weather pattern that will move through the Kennedy Space Center in Florida on Thursday. The storm front has already spawned a string of tornadoes in five south-central states that killed at least 50 people late Tuesday.

Shuttle weather officer Kathy Winters says more severe weather is unlikely, but she says the storm front may hamper the launch.

"Our concerns are having showers in the area, low ceilings, and even a potential for thunderstorm," said Kathy Winters. "So with that we do have a 70 percent chance of weather prohibiting launch for tomorrow."

Winters says the weather system should be gone by Friday or Saturday to allow the launch to take place.

Atlantis is set to dock at the International Space Station and deliver the Columbus science laboratory that was built by the European Space Agency. The seven-meter-long module will provide new room and tools for astronauts to conduct research in space.

Space station program manager, Alan Thirkettle, said the module is the heart of the agency's $7-billion program.

"We will have the right to have our astronauts flying on there [the station] to perform the iterative science that they can do so well, and to be the icons for the youths of the future in Europe as well," said Thirkettle.

He said the module will carry equipment for two initial experiments, including one to study the sun and another to test materials for future space vehicles.

Once attached to the space station, the Columbus module also will be used to receive supplies from an unmanned shuttle system that European engineers are preparing to launch. Thirkettle said the Automated Transfer Vehicle is crucial to deliver food, water, fuel and other supplies to astronauts aboard the station.

"It contains a menu of cargo, and on any one mission it can carry up to six tons of usable cargo to the station," he said.

He said space officials hope to use the cargo system to carry 45 tons of supplies into space over the next year to further construction on the space station.

NASA officials have planned at least five shuttle flights this year to help meet a 2010 deadline for completing expansion of the space station.