At Astrotech Space Operation's payload processing facility in Titusville probe comes to rest on the spacecraft adapter ring.

At Astrotech Space Operation's payload processing facility in Titusville, Fla., NASA's Gravity Recovery and Interior Laboratory-B (GRAIL-B) lunar probe comes to rest on the spacecraft adapter ring. At right is GRAIL-A. After the twin GRAIL spacecraft are attached to the adapter ring in their side-by-side launch configuration, they will be transported to the launch pad.

GRAIL will fly in tandem orbits around the moon for several months to measure its gravity field. GRAIL's primary science objectives are to determine the structure of the lunar interior, from crust to core, and to advance understanding of the thermal evolution of the moon. Launch aboard a United Launch Alliance Delta II rocket from Space Launch Complex 17B on Cape Canaveral Air Force Station is scheduled for Sept. 8. For more information, visit http://www.nasa.gov/grail. Photo credit: NASA/Jim Grossmann