Weather Again Halts Endeavour Blastoff to ISS

Stormy Florida weather July 13 postponed the launch of the Space Shuttle Endeavour for the third consecutive day and marked the fifth time since June that NASA has been forced to postpone the mission to deliver and install Japan's 4.5 million-ton Kibo space-exposed laboratory complex.

NASA was optimistic about a July 13 launch late in the afternoon as storms south of Cape Canaveral began moving outside the 20-mile radius of the shuttle landing facility, but storms from the north then began to move into the area.

NASA made the no-go decision at 6:39 p.m. EDT and scheduled the next attempt at liftoff for July 15 at 6:03 p.m. The current weather forecast for July 15 suggests a 60 percent chance of takeoff.

"Weather has just bitten us again," Launch Director Pete Nickolenko told Endeavour's seven astronauts. Endeavour Commander Mark Polansky replied, "That is the nature of our business. When the time is right, we'll be here and we'll be ready."

After the Endeavour crew leaves the space shuttle and the external tank is drained of its propellants, a service structure will be rolled into place around Endeavour to protect it from rain and other conditions.

Late-night storms on July 10 had forced NASA to cancel the scheduled July 11 liftoff after lightning strikes hit some launch facilities. Thunderstorms and lightning again shut down the launch on July 12. The mission was scratched twice in June due to a mysterious launch-pad hydrogen gas leak that appears to have been resolved. After NASA completed a fueling test July 1, the space agency declared the problem fixed and there were no reported leaks during fueling for the canceled July 11 liftoff.

Endeavour is now scheduled to dock at the ISS July 17 with a cargo bay full of work that includes what Polansky calls "really big pieces of equipment" that are needed to complete Japan's Kibo laboratory complex. The 16-day mission-the second longest in shuttle mission history-will require five spacewalks to unload and install a literal "front porch" for the ISS, allowing for space-exposed science experiments.

"It's a real exciting mission. We are the last mission that is taking up Japanese hardware on a space shuttle ... really big pieces of equipment that we're going to go ahead and leave behind on the space station for construction," Polansky said in a preflight interview.

Also inside Endeavour's cargo bay will be an integrated cargo carrier holding several pieces of spare equipment for the space station. Most of it-a spare space-to-ground antenna, a spare linear drive unit and a spare pump module-will be stored on an external storage platform on the station's truss. Six batteries for the station's oldest solar array will be installed.

Once the Endeavour reaches the ISS, things will be busy inside the shuttle and space station, with all three of the available robotic arms being put to use, sometimes all on the same day. The shuttle's Canadarm and the station's Canadarm2 will be put through their regular paces for surveys, unloading cargo and moving equipment and spacewalkers around, and a new Japanese robotic arm will be making its debut to transfer science experiments.

"It's certainly really exciting for JAXA [Japan Aerospace Exploration Agency]," said Polansky. "For them, this is the last of their hardware that's going to be permanently attached to the space station. This completes their series."

The mission also marks another milestone for JAXA, with Japanese flight controllers on the ground operating their own berthing mechanisms for the first time. The Kibo external facility will never need to be connected to anything but a Japanese-built module, so JAXA was free to use any berthing mechanism.

"Before, even when we had pieces of hardware that were built by someone else, we have, here in the U.S. control center, still maintained a lot of the technical leadership," said Lead Space Station Flight Director Holly Ridings. "In this case, they truly have technical leadership for some of the things that must work to make the mission a success. It's unique."