KENNEDY SPACE CENTER, Florida (CNN) -- NASA said Saturday it has postponed the launch of space shuttle Endeavour for at least 24 hours after lightning struck nearly a dozen times near the launch pad.
Space shuttle Endeavour, shown here last month, is rolled out to its launch pad at the Kennedy Space Center.
"We need to be 100 percent confident that we have a good system across the board ... [we're going to] spend 24 more hours to just make sure that we're good," said Mike Moses, the space shuttle program integration manager.
Moses, speaking to reporters in a morning briefing, said 11 strikes hit within a half-mile of the launch pad Friday night.
However, he said, "We've seen nothing so far that indicates anything was actually affected by the lightning strikes." Watch lightning strike the shuttle launch pad »
He added, "I fully expect this to be a positive story, but we have a lot of equipment that has to be checked." View behind-the-scenes images of Endeavour »
Endeavour had been scheduled to take off at 7:39 p.m. Saturday. The next attempt is set for 7:13 p.m. Sunday.
This is the third time Endeavour's launch has been delayed. It was postponed twice last month because of a liquid hydrogen leak.
Endeavour, carrying seven astronauts and a key component for Japan's Kibo science laboratory, is to head to the International Space Station for a 16-day mission. Five spacewalks are planned for the crew after the shuttle docks. View an interactive of what mission will do in space »
The Kibo science lab, also called the Japanese Experiment Module, is Japan's first human space facility, and has been more than 20 years in the making.
The mission's primary goal will be to install what amounts to a porch in space. Endeavour is carrying in its cargo bay two platforms of the Japanese Kibo Laboratory, which is already part of the space station. One platform rides up and back on the shuttle, while the other will stay permanently fixed to the Kibo laboratory for scientific experiments that require exposure to space.
For many of the 16 days, the station will resemble a construction site, except that astronauts will be in space suits instead of hard hats and operating robotic arms instead of cranes. And just like at a job site, it will all be going on at the same time.
CNN's John Zarrella contributed to this report.