Passage: Maria Zuber of the Massachusetts Institute of Technology is GRAIL's principal investigator. NASA's Jet Propulsion Laboratory manages the project. As of August 5, 2011, the program has cost US$496 million.  Upon launch the spacecraft were named GRAIL A and GRAIL B and a contest was opened to school children to select names.  Nearly 900 classrooms from 45 states, Puerto Rico and the District of Columbia, participated in the contest.  The winning names, Ebb and Flow, were suggested by 4th grade students at Emily Dickinson Elementary School in Bozeman, Montana.Each spacecraft transmitted and received telemetry from the other spacecraft and Earth-based facilities. By measuring the change in distance between the two spacecraft, the gravity field and geological structure of the Moon was obtained. The two spacecraft were able to detect very small changes in the distance between one another. Changes in distance as small as one micron were detectable and measurable. The gravitational field of the Moon was mapped in unprecedented detail.

Question: What Lab oversees the program?
NASA's Jet Propulsion Laboratory