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 Post subject: GRAIL
PostPosted: August 28th, 2011, 8:25 pm 
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Location: Baton Rouge, LA
Ten days ago the two spacecraft of this mission were connected to the second stage of the Delta II launcher. The first launch window is 8 September. Each spacecraft will take three to four months to get to the Moon, then an additional two months correctly orienting each orbit to the other.

GRAIL will attempt to help characterize the Moon's gravitational field. The spacecraft will have the same orbit, with one following the other. Minor fluctuations in the Moon's gravity will periodically alter the distance between the spacecraft. The science team will use these noted changes to create a map of the Moon's gravitational field.

More information:
http://www.nasa.gov/mission_pages/grail/news/grail20110825.html


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 Post subject: Re: GRAIL
PostPosted: September 8th, 2011, 1:25 pm 
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One more day to wait for a GRAIL liftoff--and maybe more than that, as the possibility of good weather for tomorrow is not great.

I wonder if any revelations about the Moon's core will alter the theories of the impactor whose collison with the Earth made the Moon, and of the early makeup of the Earth's crust and mantle.

More information at:
http://www.nasa.gov/mission_pages/grail/main/index.html


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 Post subject: Re: GRAIL
PostPosted: September 14th, 2011, 11:54 pm 
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GRAIL launched Saturday morning. The spacecraft are going to take a lot longer than the Apollo craft--as I posted earlier, between three and four months to get there. GRAIL-A should arrive on 31 December, and GRAIL-B on 1 January. The GRAILs should spend almost three months' time collecting data. Good luck to them.

More information:
http://www.nasa.gov/mission_pages/grail/news/grail20110910r.html


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 Post subject: Re: GRAIL
PostPosted: December 28th, 2011, 11:37 pm 
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At this time GRAIL-A is ~106,000 kilometers, and GRAIL-B ~128,000 kilometers from the Moon. Each is travelling at 1200 km/hr.

During final approach the orbiters will fly over the lunar south pole. The orbit insertion burns, which will occur twenty-five hours apart, will bring each orbiter into a 11.5-hour polar orbit. A series of burns over the following weeks will reduce that period to less than two hours. The science phase begins in March, when the two GRAILs will be no more than 55 kilometers above the surface of the Moon.

Maria Zuber of MIT, who is GRAIL's PI, states "This mission will rewrite the textbooks on the evolution of the Moon."

More information:
http://solarsystem.nasa.gov/grail/newsdisplay.cfm?Subsite_News_ID=29396&SiteID=2


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 Post subject: Re: GRAIL
PostPosted: February 2nd, 2012, 12:31 am 
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Location: Baton Rouge, LA
GRAIL has returned the first video of the far side of the Moon. A test video taken 19 January, it's really cool, showing detail almost to the South Pole proper.

There's a nice still from the final second or two of the video. I grabbed the Reploge globe at HRPO and checked it against the still. I can see in the lower left-hand quadrant of the image the overlapping craters Rayleigh, Antoniadi and Numerov. Further to center, the crater with the small, sharp-edges crater on its rims at twelve o'clock and three o'clock is probably Zeeman. The deep crater with the peak to Zeeman's lower left is probably DeForest.

The two craft, by the way, have been named "Ebb" and "Flow".


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 Post subject: Re: GRAIL
PostPosted: June 25th, 2012, 11:34 pm 
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The GRAIL spacecraft operated continuously for eighty-nine days, from early March to late May, returned over 99.99% of the expected data. Now the GRAIL team wants to use Ebb and Flow for an extended session of studies starting 30 August, during which the craft will sent to their lowest safe altitude over the Moon. At some points during the extended mission the spacecraft will fly no more than eight kilometers over some lunar features!

The spacecraft are powered off at this time.

More information:
http://www.nasa.gov/mission_pages/grail/news/grail20120529.html


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