Holy GRAIL! Photos From NASA's Moon Gravity Mission

How the GRAIL Mission Works

Infographic shows how GRAIL mission maps the moon's gravity field

Protecting GRAIL

On Aug. 12, 2011, a crane lifts the protective canister that will enclose NASA's twin Gravity Recovery and Interior Laboratory spacecraft, at right, during transport to the launch pad. The lunar probes are attached to a spacecraft adapter ring in their side-by-side launch configuration and wrapped in plastic to prevent contamination outside the clean room.

Shine a Light on GRAIL

Lockheed Martin technicians in the Astrotech Space Operations payload processing facility in Titusville, Fla., test the solar arrays on NASA's Gravity Recovery and Interior Laboratory-A, or GRAIL-A, spacecraft on July 28, 2011, to ensure that they will function as planned during the mission.

GRAIL's Solar Array Tested

Technicians at Astrotech payload processing facility in Titusville, Fla., are conducting solar panel deployment tests on NASA's Gravity Recovery and Interior Laboratory, or GRAIL, twin spacecraft, on June 18, 2011.

Gravity Recovery and Interior Laboratory (GRAIL) Spacecraft

The twin Gravity Recovery and Interior Laboratory (GRAIL) spacecraft are mirror images of one another. The probes will orbit the moon and take detailed measurements of the lunar gravity field.

NASA's Grail Mission at the Moon

Artist's concept of NASA's Grail mission. Grail's twin spacecraft are flying in tandem orbits around the moon to measure its gravity field in unprecedented detail.

GRAIL Moved to the Test Stand

Technicians lift one of two spacecraft for NASA's Gravity Recovery and Interior Laboratory, or GRAIL, to a test stand in the Astrotech payload processing facility in Titusville, FL, on May 21, 2011.

Double Your Spacecraft

NASA's Gravity Recovery and Interior Laboratory, or GRAIL, twin spacecraft stand side by side as they are prepared for testing and processing in the Astrotech payload processing facility in Titusville, Fla.

GRAIL's Airport Arrival

NASA's two Gravity Recovery and Interior Laboratory, or GRAIL, spacecraft wait to be offloaded from an Air Force C-17 cargo plane on the Shuttle Landing Facility at Kennedy Space Center in Florida. The pair of lunar probes traveled to the spaceport from the Lockheed Martin plant in Denver, CO, on May 20, 2011.

Assembling GRAIL'S Delta 2 Rocket

At NASA's Space Launch Complex 17B in Florida, the first and second stages of a Delta II launch vehicle and its nine solid rocket boosters are visible in the mobile service tower on May 10, 2011. The Delta II will launch NASA's Gravity Recovery and Interior Laboratory, or GRAIL, spacecraft on a lunar mission.