NASA has delayed until Friday the launch of space shuttle Atlantis after engineers discovered problems with the shuttle's external tank. VOA's Brian Wagner reports the shuttle is set to deliver a new laboratory to the International Space Station.

NASA officials say they discovered the problem as they were filling the shuttle's external tank with liquid hydrogen at the Kennedy Space Center in Florida. Engineers agreed to delay Thursday's scheduled launch to allow time to inspect two malfunctioning fuel sensors in the tank and perform any needed repairs.

Officials say they hope to launch on Friday, if the problem is resolved.

The shuttle Atlantis is to carry into space a seven-meter-long research laboratory called Columbus, built by the European Space Agency. Alan Thirkettle, station program manager for the European agency, says the Europeans have invested more than two decades of work and a great deal of pride in the space module.

"The taxpayers as well should share in that pride. I hope they are going to not only see and enjoy the mission itself, but also benefit from the work that goes on inside Columbus," said Thirkettle.

The seven-member crew of Atlantis will conduct at least three space walks to attach the $2 billion module to the International Space Station. European officials say the lab will enable astronauts to perform scores of experiments into biotechnology and medicine, as well as into conditions that may affect astronauts on long-term space flight.

The 17-nation European Space Agency also is developing a system to launch automated missions that will deliver supplies to the space station next year.

The Atlantis flight is one in a series of missions planned to speed the expansion of the International Space Station by 2010. In February, officials plan to begin a series of three shuttle flights to deliver the components of a Japanese-built research module called Kibo.