GRAIL on the Launchpad
September 9, 2011

GRAIL Launch Postponed Until Saturday


Thursday´s scheduled launch of the Delta II rocket carrying NASA´s Gravity Recovery and Interior Laboratory (GRAIL), which was postponed to Friday morning at 9:16 a.m., has been postponed again until Saturday, September 10.

NASA delayed the initial launch due to upper-level winds that may have posed a threat. The space agency said the high winds at Cape Canaveral Air Force Station in Florida prevented a launch opportunity at 8:37 a.m. on Thursday.

The agency pushed the launch to Friday initially, but have now said it will be pushed again to Saturday to give them additional time to review propulsion system data from Thursday´s detanking operation after the launch was scrubbed.

The launch is now scheduled for Saturday morning from Space Launch Complex-17B at Cape Canaveral. There are two instantaneous launch opportunities: one at 8:29 a.m. and a second at 9:08 a.m. EDT. Saturday´s forecast shows a 60 percent chance of favorable weather conditions for a morning launch.

The GRAIL mission consists of two twin spacecraft that are built to help scientists understand more about the structure of the lunar interior. The orbiters will ride aboard a United Launch Alliance Delta II 7920H-10C rocket, NASA´s most powerful rocket.

Once in lunar orbit, the spacecraft will transmit radio signals precisely defining the distance between them. Regional gravitational differences on the moon are expected to expand and contract that distance. The twin orbiters will fly a circuitous route to lunar orbit taking 3.5 months and covering more than 2.5 million miles each.


Image Caption: NASA's GRAIL twin spacecraft await launch atop a United Launch Alliance Delta II rocket at Cape Canaveral Air Force Station, Fla. Image credit: NASA/JPL-Caltech/United Launch Alliance, Thom Baur


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