Lightning and thunderstorms thwarted NASA's attempt to launch the space shuttle Discovery early Tuesday, forcing its seven-astronaut crew to wait at least one more day before leaving the planet.
Discovery was slated to blast off from a seaside launch pad here at NASA's Kennedy Space Center at 1:36 a.m. ET Tuesday, with forecasts predicting an 80 percent chance of good launch weather. But that nearly pristine forecast crumbled away late Monday as lightning, rain showers and thick clouds unexpectedly cropped up to prevent the launch.
Lightning struck near the launch pad several times, at times within 5 miles (8 kilometers), while Discovery's seven astronauts were strapped into their seats hoping for liftoff. Camera views showed rain pouring down on the launch pad during the countdown. The weather did improve closer to launch time, but it was not enough to clear Discovery for liftoff, mission managers said.
"The vehicle and operations were cooperating, but unfortunately the local weather did not," NASA launch director Pete Nickolenko told Discovery's crew. "We'll have to scrub for today and just try again tomorrow."
"We copy," Discovery commander Rick Sturckow radioed back. "As soon as the weather will be ready to cooperate, we'll be ready to go."
Discovery is now slated to launch no earlier than Wednesday at 1:10 a.m. ET.
The chief weather concerns for Discovery's launch attempt Tuesday were rain and thick clouds near the launch pad, as well as lightning and thunderstorms too close to a nearby runway that is reserved in case the shuttle suffers an emergency during liftoff, said Lt. Col. Patrick Barrett of the Air Force's 45th Weather Squadron.
Barrett told Space.com that there is a 70 percent chance of good weather for Discovery's next launch opportunity on Wednesday.
Stormy weather, and lightning in particular, has been a thorn in NASA's side for shuttle launches of late. The July launch of shuttle Endeavour was delayed five times due to lightning and foul weather. Lightning also slowed Discovery's trek to the launch pad earlier this month.
NASA has until Aug. 30 to launch the shuttle before standing down due to restrictions on the launch range it shares with the nearby Cape Canaveral Air Force Station. NASA wants to launch Discovery by the end of August to avoid a traffic conflict with an unmanned Japanese cargo spaceship also due at the space station this month. If the mission is unable to launch by then, NASA can try again on Oct. 17.
Discovery's mission is slated to fly to the international space station to deliver nearly 8 tons of cargo, including new science gear and a treadmill named after comedian Stephen Colbert. The 13-day mission will also ferry astronaut Nicole Stott to the station to replace NASA astronaut Tim Kopra, who has been living aboard the orbiting lab since mid-July.
Set to launch aboard Discovery with Sturckow and Stott are STS-128 pilot Kevin Ford and mission specialists Patrick Forrester, Jose Hernandez, Danny Olivas and Swedish astronaut Christer Fuglesang. Fuglesang represents the European Space Agency, while the rest are NASA astronauts. Three spacewalks are planned for their mission.
Stott is set to begin a three-month mission to the space station as a flight engineer on the outpost's six-person Expedition 20 crew. She will join two Russians, another American and astronauts from Belgium and Canada on what is the station's first full-sized crew.
If Discovery is unable to launch Wednesday, the next opportunity is Thursday at 12:52 a.m. ET.
This report includes information from The Associated Press and msnbc.com.