Gravity Recovery and Interior Laboratory (GRAIL, a similar probe intended to map the moon)

Gravity Recovery and Interior Laboratory - US Lunar orbiters (2011)

Two identical satellites, collectively known as the Gravity Recovery and Climate Experiment, or Grace, travel one behind the other in a polar orbit separated by about 130 miles.

The Gravity Recovery and Interior Laboratory mission will create the most accurate gravitational map of the moon to date.

Gravity Recovery and Climate Experiment (GRACE)

To get the most detailed measurements ever taken of these changes, scientists have launched the Gravity Recovery and Climate Experiment, or Grace.

The Gravity Recovery and Interior Laboratory, or GRAIL, lifted off in September to study the moon from crust to core.

The Gravity Recovery and Climate Experiment (GRACE) consists of two satellites that can detect gravitational changes across the Earth.

At this very moment, twin satellites - part of the Gravity Recovery and Climate Experiment, or Grace - are in polar orbit above the earth.

Gravity Recovery and Climate Experiment (2002)