Stormy Weather Keeps Clouding Last Shuttle Launch on Friday
At NASA's Kennedy Space Center in Florida, space shuttle Atlantis moves through the perimeter fence at Launch Pad 39A. Go Atlantis!
Credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. — NASA's space shuttle Atlantis is all packed up for the agency's historic last launch of its winged spaceship tomorrow (July 8), but foul weather continues to threaten the upcoming liftoff.

NASA hopes to unveil Atlantis atop its seaside launch pad here at the Kennedy Space Center this afternoon for tomorrow's planned 11:26 a.m. EDT (1526 GMT) launch, but only if the stormy weather allows.

Kathy Winters, NASA's shuttle launch weather officer, told reporters that lightning and thunderstorms are the main threat. Only once they clear out will NASA retract the protective clamshell-like covering that shields Atlantis from the elements. [Shuttle Launch Countdown: T-9 Minutes to Blastoff]

The weather outlook for launch day remains glum, Winters added. The odds, as they stand now, are against NASA.

"I wish I had better weather for you but we do have a 70 percent chance of weather prohibiting launch," Winters said in a briefing. 

NASA currently has until Sunday (July 10) to try to launch Atlantis before the agency would have to stand down to avoid a space traffic conflict with an Air Force rocket launch next week. The weather forecast for Saturday improves slightly, with the likelihood of unacceptable weather at 60 percent. By Sunday, those odds drop to 40 percent, Winters said.

All packed up

Space shuttle Atlantis will launch four astronauts on one final flight for NASA's 30-year-old shuttle program, which is shutting down this year. The 12-day mission will deliver a huge load of cargo to the International Space Station to help keep the orbiting lab running after the shuttle fleet retires.

Joe Delai, NASA's cargo chief for Atlantis' mission, said workers are packing the final items inside the shuttle today, before saying goodbye for good. Atlantis is carrying about 9,500 pounds of cargo packed away on the shuttle and inside a huge cargo pod inside the shuttle's 60-foot payload bay.

"This isn't just a bit of metal," Delai said of the shuttle's cargo. "It's a way of life. It's what we do … Yeah, it's emotional, but it's also a part of history."

Atlantis' final astronaut crew has stashed some secret souvenirs to mark NASA's last shuttle flight, but they don't expect any surprise treats stowed away by Delai and his team.

"I wasn't able to get anything on this flight," Delai said.

NASA's final shuttle flight

NASA is retiring the space shuttle fleet to make way for a new program aimed at deep space exploration. The space agency has a new wingless spaceship, the capsule-based Multi-Purpose Crew Vehicle, in development to carry astronauts to an asteroid by 2025, a goal set by President Barack Obama.

The first flight of that capsule is still years away, though, and NASA hopes to rely on privately built American spaceships to ferry astronauts to and from orbit once they become available. Until then, the space agency will continue buying seats on Russian Soyuz capsules.

Today, NASA chief Charles Bolden signed a commercial space agreement with the private spaceflight company Sierra Nevada Corp., which is one of several contenders vying to provide commercial crew launch services to the agency. The agreement allows NASA's Kennedy Space Center workforce to provide its expertise to Sierra Nevada as the company develops its Dream Chaser space plane, a vehicle that has NASA heritage.

"We're pleased that our partner Sierra Nevada is going to make use of the deep resources existing at the Kennedy Space Center to enhance its ongoing work," Bolden said.

Visit SPACE.com for complete coverage of Atlantis' final mission STS-135 or follow us @Spacedotcom and on Facebook.