Concerns over the International Space Station's angles and exposure to sunlight during late December and early January have led SpaceX to again postpone the launch of their Dragon capsule to resupply the station. Next target date is Jan. 6, 2015.
The Dragon was supposed to go up Friday afternoon atop SpaceX's Falcon 9 rocket.
It's the third time the launch date has been reset.
And this would be the first commercial resupply of the space station since a competing company's resupply capsule was lost in an explosion Oct. 28, when the Orbital Sciences had its Antares rocket explode on launch at NASA's Wallops Island, Va., launch complex.
The last successful commercial resupply mission of the space station occurred with SpaceX's previous launch, in September, though some supplies were carried to the station on a Russian Soyuz in November.
Here's the explanation NASA provided Thursdaymorning when it announced SpaceX was postponing:
"This will provide SpaceX engineers time to investigate further some of the issues that arose from the static fire test of the Falcon 9 rocket on Dec. 16 and will avoid beta angle constraints for berthing the Dragon cargo ship to the station that exist through the end of the year.
"Beta angles are the angles between the space station orbital plane and the sun, resulting in the station being in almost constant sunlight for a 10 day period. During this time, there are thermal and operational constraints that prohibit Dragon from berthing to the station. This high beta period runs from Dec. 28 through Jan. 7.