Twin moon-bound NASA spacecraft were trucked to a Cape Canaveral launch pad overnight and mated to their rocket this morning.
NASA's $496-million Gravity Recovery and Interior Laboratory mission, or GRAIL, remains on track for an 8:37 a.m. blastoff Sept. 8 atop a United Launch Alliance Delta II Heavy rocket.
A protective shell is scheduled to be attached around the Lockheed Martin-built spacecraft next Thursday.
Together, the spacecraft will spend more than 80 days mapping the moon's gravitational field, providing new insights into its interior structure and composition and its formation and development over time.
IMAGE: NASA's twin Gravity Recovery and Interior Laboratory (GRAIL) spacecraft are lifted to the top of their launch pad today at Launch Complex 17B at Cape Canaveral Air Force Station. Photo credit: NASA/Kim Shiflett