Updated

Thunderstorms forced NASA to call off shuttle Discovery's launch to the international space station early Tuesday.

Launch managers said they would try again Wednesday.

The storms popped up unexpectedly late Monday all around the launch site, and lightning lit up the sky. A strike was reported just five miles from the pad, in fact, and then it started to pour. The storms finally eased, but not fast enough.

Launch director Pete Nickolenko waited as long as he could before halting the countdown. The space shuttle had seven astronauts inside as well as thousands of pounds of space station supplies, including a new treadmill named for TV comedian Stephen Colbert.

"The vehicle and the operations were cooperating, but the local weather unfortunately did not," Nickolenko informed the astronauts.

"When the weather is ready to cooperate, we'll be ready to go," replied commander Rick Sturckow.

Another 30 minutes, and "I think we'd have a real good shot today," said Mike Moses, chairman of the mission management team. Time, unfortunately, ran out in the wee hours.

Forecasters put the odds of good launching weather Wednesday at 70 percent.

Discovery's most prominent payload is NASA's new $5 million treadmill, which is named after Colbert. He could not attend the launch, but said in a recorded message that he couldn't be prouder that his treadmill soon will be installed at the space station "to help finally slim down all those chubby astronauts."

"Let's face it, being weightless is mostly just a desperate bid to get away from that bathroom scale every morning," Colbert said. "But you guys and gals are ambassadors to the universe. Don't make us look bad. Put down the astronaut ice cream, tubby. Tubby, tubby, two-by-four, couldn't fit through the air lock door."

Colbert campaigned earlier this year to have a space station room named after him. He won the online vote, but NASA went with Tranquility, the name of the dry lunar sea in which Neil Armstrong and Buzz Aldrin landed 40 years ago this summer. As a consolation prize, Colbert got the treadmill. It's full name is Combined Operational Load Bearing External Resistance Treadmill; it will fly up in more than 100 pieces and won't be put together until sometime next month.

Colbert poked fun at NASA's choice of Tranquility for the chamber, which will be launched early next year. "Yeah, that will scare the aliens," he said. He ended his televised message by shouting, "I am 'go' to launch me. Let's light this candle!"

That was before the storms moved in.

NASA has until the end of August to launch Discovery. Otherwise, it will have to wait for a Japanese cargo ship and Russian Soyuz spacecraft to fly in September. That would push the 13-day shuttle flight into October.