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Emily Lakdawalla • Sep 10, 2011

GRAIL A and B are on their way to the Moon!

After some exasperating delays due to pesky and changeable high-level winds, the twin GRAIL spacecraft launched this morning on their trip to the Moon. Official launch time was 13:08:52.775 UTC on September 10, 2011. Go GRAIL!

Liftoff for GRAIL!
Liftoff for GRAIL! Liftoff for the GRAIL mission to the Moon at 13:08UTC on September 10, 2011! From @carlmilnerImage: Carl Milner

About an hour and a half later, both spacecraft successfully separated from their launch vehicle, an event shown live on NASA TV thanks to a RocketCam!

GRAIL A separates from its second stage rocket
GRAIL A separates from its second stage rocket Image: NASA / RocketCam / animation by Emily Lakdawalla

Via Twitter I've learned that both spacecraft have deployed their solar panels and are producing power. Now they're on their way for a three-month cruise to the Moon via the Sun-Earth L2 point. The long cruise reduces the amount of fuel they need for lunar orbit insertion, and also allows the spacecraft to outgas before it has to perform its sensitive gravity measurements.

A special congratulations to Principal Investigator Maria Zuber and the whole science team, who can now get to work!

EDIT: Youtube video of both GRAILs separating:

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GRAIL spacecraft separation NASA's Twin GRAIL spacecraft head for their lunar mission aboard a Delta II rocket at 13:08:52.775 UTC on September 10, 2011.Video: NASA

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