NASA has delayed Wednesday's launch of Space Shuttle Atlantis on its STS-115 mission to the International Space Station. Shuttle Program managers made the decision early Wednesday morning due to a problem that occurred during the activation of one of the shuttle's three electricity-producing fuel cells.

Teams are evaluating data on what might have caused a voltage spike in the fuel cell's coolant pump that cools the fuel cell system. Mission managers will hold a meeting at 1 p.m. EDT Wednesday to assess the issue. There will be a news conference on NASA TV at the conclusion of the meeting.

During STS-115, the astronauts will deliver and install a girder-like structure, known as the P3/P4 truss aboard the station. The 35,000-pound piece includes a set of giant solar arrays, batteries and associated electronics. The arrays eventually will double the station's power capability.

Atlantis' crew, Commander Brent Jett, Pilot Chris Ferguson and Mission Specialists Dan Burbank, Heide Stefanyshyn-Piper, Joe Tanner and Steve MacLean, a Canadian Space Agency astronaut, remains at Kennedy Space Center.

For the latest information about the STS-115 mission and its crew, visit:

http://www.nasa.gov/shuttle