A weather satellite is scheduled for launch early Friday from California atop a United Launch Alliance Delta II rocket.
The $1.5 billion National Polar-orbiting Operational Environmental Satellite System Preparatory Project, or NPP, will blastoff from Vandenberg Air Force Base in California. The launch window opens at 5:48 a.m. and runs to 5:57 a.m.
Forecasters say there's a 100 percent chance of weather conditions favorable for launch.
Live NASA TV coverage begins at 3:01 a.m. EDT.
For more background on the mission, check out this NASA Press Kit and ULA's Mission Operations Booklet.
And read a USA Today story about the next class of weather satellites potentially being at risk due to funding concerns.
NASA and ULA teams from the Cape are in Vandenberg to work the launch.