GRAIL mission to Earth's Moon. Credit: NASA/JPL-Caltech
Twin robotic probes to orbit Earth’s Moon are ready for their launch to chart our next-door neighbor’s gravity field in unprecedented detail.
The Gravity Recovery and Interior Laboratory (GRAIL) mission by NASA will make use of two spacecraft that fly in tandem orbits around the Moon.
The lunar satellites should beam scientists detailed measurements of the Moon’s gravity field to, in essence, peer deep inside the moon from crust to core to reveal subsurface structures and, indirectly, its thermal history.
The spacecraft twins, GRAIL-A and GRAIL-B, will fly aboard the same Delta II rocket that’s launched from Florida.
GRAIL’s launch period opens Sept. 8 and extends through Oct. 19.
GRAIL’s twin spacecraft are tasked for a nine-month mission to explore Earth’s nearest neighbor.
Precisely, what’s going on?
Why two spacecraft?
Using a precision formation-flying technique, the twin GRAIL spacecraft will map the Moon’s gravity field.
Radio signals traveling between the two spacecraft provide scientists the exact measurements required as well as flow of information not interrupted when the spacecraft are at the lunar farside – the side not seen from Earth.
As a result, GRAIL should provide the most accurate gravity map of the Moon ever made.
The mission also will answer longstanding questions about Earth’s moon, including the size of a possible inner core, and it should provide scientists with a better understanding of how Earth and other rocky planets in the solar system formed.
Putting GRAIL together
GRAIL is a part of NASA’s Discovery Program.
NASA’s Jet Propulsion Laboratory, Pasadena, Calif., manages the GRAIL mission.
The Massachusetts Institute of Technology, Cambridge, is home to the GRAIL principal investigator, Maria Zuber.
Lockheed Martin Space Systems, Denver, built the spacecraft.
Take your own moonshot by visiting GRAIL websites at:
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By Leonard David