After more than four years, NASA’s space shuttle Endeavour will have to wait just a bit longer to return to the launch pad after anticipated bad weather prevented an early morning rollout at the Kennedy Space Center today.

Endeavour, which last flew in 2002 before standing down for an overhaul, was slated to begin the 3.4-mile trek between NASA’s cavernous Vehicle Assembly Building and Pad 39A at KSC in Cape Canaveral, Florida at 12:01 a.m. EDT (0401 GMT), but mission managers delayed that process to 3:00 a.m. EDT (0700 GMT) before scrapping the effort altogether.

“NASA launch operations managers decided to stand down from today’s planned rollout due to unfavorable weather, which was predicted to arrive before they could make it to the launch pad,” NASA spokesperson Bill Johnson said.

NASA space shuttles are protected from the elements while inside the 52-story Vehicle Assembly Building and are shielded from weather by a shroud-like Rotating Service Structure at the launch pad, but are vulnerable during the slow trip to cover the space in between. The launch pad trek atop a massive NASA crawler carrier vehicle generally takes between six and seven hours, NASA said.

Johnson said NASA will try again tonight to roll Endeavour and its external fuel tank and solid rocket boosters across the 3.4-mile stretch to Pad 39A. Shuttle workers are due to arrive at their positions at about 6:00 p.m. EDT (2200 GMT) tonight with Endeavour’s first motion slated for about 10:00 p.m. EDT (0200 July 11 GMT).

Endeavour is slated to launch on Aug. 7 with NASA’s STS-118 astronaut crew commanded by veteran shuttle flyer Scott Kelly. The planned 11-day mission will deliver fresh cargo, spare parts and a new piece of starboard-side truss to the International Space Station, and features the first flight of NASA educator astronaut Barbara Morgan.

NASA first selected Morgan for shuttle flight in 1985, when she was chosen to serve as backup for schoolteacher Christa McAuliffe during the Teacher in Space Program. McAulliffe and her six crewmates died during the Challenger accident and Morgan later returned to teaching before rejoining NASA as a full-fledged educator astronaut in 1998.