Image above: As dawn breaks at NASA's Kennedy Space Center, Space Shuttle Atlantis waits at Launch Pad 39B. Photo credit: NASA

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Launch delayed by fuel cell problem

The launch of Space Shuttle Atlantis was postponed today for at least 24 hours due to a problem that occurred Tuesday night during the activation of one of the shuttle's three electricity-producing fuel cells. A spike and drop in voltage was noticed on fuel cell number one. Troubleshooting is ongoing, and the problem has been isolated to a coolant pump that helps cool the fuel cell system.

The Mission Management Team is scheduled to meet at 1p.m. EDT today to review more data and assess the problem, and a news conference will follow.

Space Shuttle Fuel Cells
The space shuttle's fuel cell system is made up of three cells, which are located under the payload bay liner in the forward portion of the orbiter's midfuselage. Each 255-pound reusable cell is 14 inches high, 15 inches wide and 40 inches long. The three cells operate as independent electrical power sources that generate heat and water as by-products of the power generation. The water is stored and used for the environmental control and life support system.

Atlantis' Crew and Mission
The STS-115 crew consists of Commander Brent W. Jett Jr., Pilot Christopher J. Ferguson and Mission Specialists Heidemarie M. Stefanyshyn-Piper, Joseph R. Tanner, Daniel C. Burbank and Steven G. MacLean, who represents the Canadian Space Agency.

With this mission, NASA is ready to get back to building the International Space Station, marking the first time in almost four years that a space station component has been added to the orbiting outpost. That also means the shuttle program is coming up on some of the most challenging space missions ever.

During their three spacewalks, crew members of Atlantis will install the P3/P4 integrated truss and a second set of solar arrays on the space station, doubling the station’s current ability to generate power from sunlight and adding 17.5 tons to its mass.
Read more about the P3/P4 truss