Launching the Lunar Grail
NASA Moon mission in final preparations for September launch
GRAIL’s twin spacecraft are tasked for a nine-month mission to explore Earth’s nearest neighbor in unprecedented detail. They will determine the structure of the lunar interior from crust to core and advance our understanding of the thermal evolution of the Moon.
“Yesterday’s final encapsulation of the spacecraft is an important mission milestone,” said David Lehman, GRAIL project manager for NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “Our two spacecraft are now sitting comfortably inside the payload fairing which will protect them during ascent. Next time the GRAIL twins will see the light of day they will be about 95 miles up and accelerating.”
The spacecraft twins, GRAIL A and B, will fly a circuitous route to lunar orbit taking 3.5 months and covering approximately 2.6 million miles (4.2 million kilometers) for GRAIL-A, and 2.7 million miles (4.3 million kilometers) for GRAIL-B.
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. GRAIL scientists will use these accurate measurements to define the Moon’s gravity field. The data will allow mission scientists to understand what goes on below the surface of our natural satellite.
GRAIL’s launch period opens Sept. 8 and extends through Oct. 19. On each day, there are two separate launch opportunities separated by approximately 39 minutes. On Sept. 8, the first launch opportunity is 8:37 a.m. EDT; the second is 9:16 a.m.
The Moon is our nearest neighbor in space, and its formation and evolution have been closely tied to the Earth. Astrobiologists are interested in studying the Moon for many reasons. Some scientists believe that the Moon plays a role in maintaining the habitabliity of Earth by influencing environmental phenomenon like ocean tides. Additionally, studying the physical properties of the Moon can help astrobiologists understand how rocky bodies form and evolve, providing valuable information in the search for small, rocky worlds throughout the Universe.