NASA Scrubs Endeavour Launch Yet Again

Thunderstorms forced NASA to call off Sunday evening's launch of shuttle Endeavour, the fourth delay for the space station construction mission.

The launch team came within minutes of sending Endeavour and seven astronauts to the international space station. But storms quickly moved in from the west and violated NASA's safety rules, and managers halted the countdown. They will try again Monday, despite an outlook calling for more bad weather.

There were no leaks or technical problems of any significance during today's countdown and Endeavour's external tank was loaded with a half-million gallons of rocket fuel without incident, reports CBS News Space Analyst Bill Harwood.

Commander Mark Polansky and his crewmates began strapping in a few minutes before 4 p.m. EDT, hopeful about finally kicking off a 16-day space station assembly mission.

But as the afternoon wore on, storm cells began pushing in from the west and forecasters predicted thunderstorms or showers within 20 nautical miles of the shuttle's emergency runway, Harwood reports. NASA flight rules forbid a launch if forecasters predict rain near the runway a half hour after launch when the crew would have to attempt an emergency landing in the event of an engine failure early in flight.

Launch Director Pete Nickolenko called off the countdown at the T-minus nine-minute mark.

"Roman, we got the vehicle ready and the weather unfortunately did not cooperate with us today, we had some colliding sea breezes," Nickolenko radioed just after 7 p.m. "We're going to have to declare a scrub for today and try to bring the team back for another attempt tomorrow."

"We understand and we'll be ready," Polansky replied from Endeavour's flight deck.

NASA has until Tuesday, possibly Wednesday, to launch Endeavour with the final piece of Japan's space station lab. Otherwise, it will have to wait until the end of July because of a Russian supply ship that's awaiting liftoff.

The three previous countdowns never made it this far.

Saturday's launch attempt was foiled by a series of lightning strikes around the pad that required extra checks of the many critical shuttle systems. Back in June, hydrogen gas leaks held everything up.

Endeavour holds the third and final segment of Japan's enormous $1 billion space station lab, named Kibo, or Hope. It's a porch for experiments that need to be exposed to the vacuum of space. The shuttle also is loaded with large spare parts for the space station and hundreds of pounds of food for the six station residents.

When the shuttle astronauts finally arrive at the space station, they will make up the biggest crowd ever in a single place in orbit: 13 people.

All of the major space station partners will be represented: the United States, Russia, Canada, Europe and Japan.

Endeavour will spend nearly two weeks at the space station. In all, the flight will last 16 days. Five spacewalks are planned to hook up the Japanese lab's new porch, replace space station batteries and perform other maintenance.

Eight shuttle flights remain, including this one, before NASA retires the fleet. All involve space station work.

For more info: