The first of the two unmanned spacecraft flying NASA's $496-million Gravity Recovery And Interior Laboratory (GRAIL) mission is scheduled to fire its main engine at 4:21 p.m. EST Saturday, New Year's Eve, to begin dropping into orbit around the moon.

Their goal is to map the moon's gravity field in the greatest detail yet, information that will provide new information about the moon's interior composition and evolution.

Interesting science. What is to be gained from this knowledge? Any Scientist to explain?

Well im just guessing here, but!

No better way to map the interior alien structures than by rendering a 3-D image of it. The GRAIL will do just that and will not present it self as a weapon to them. Find the soft spot, land it, deteonate it, and gain entry.

This will however stir the bee's nest!

That or its just gonna map the gravitation forces of the moon.

Hahahaha yeahhh right!

The gravity could tell you the make up of the core...as many a conspiracy will tell you it is hollow. It will also tell you about how it was formed possibly.

They'll probably just get downed by Iran anyway.

Oh wow I didn't know they had sent something to the moon recently or will rather. I really need to keep in touch with the space news. Wonder what the result will bring, not to big on gravity equations or anything. I hope this will give us some information on the moon to put some things to rest.

What starts in March is the opportunity for school kids to suggest areas of the moon to be surveyed by the small on-board cameras, (an initiative championed by Sally Ride) a program to get the young interested in space exploration by the possibility that their suggestion would be carried out from of all those that sent a request in. The GRAIL mission is a short lived mission while the sun's interference is less in recording the data.

What is interesting about the tandem spacecrafts is the accuracy in their flight path around the moon to make these measurements, described as being able to orbit at a distance from each other to the point of not deviating by more than the distance of a human red blood cell.

All of this on two separate spacecrafts both the size of a typical washing machine in an energy efficient route to the moon. From the time this was on the ground to the time they left earth orbit was less than an hour, the launch got them in earth orbit in about 4 minutes, when their orbit reached the proper escape attitude the escape rockets fired and in a minute or so the washing machines were on their own, in a slow elliptical approach flight path to the moon so little energy would be needed to slow them to achieve lunar orbit.

The NASA website for this moon mission says the actual measuring of gravity won't start until March 2012.

OK.... but what are they doing there now? Oh yes of course, they are calibrating the instruments, I see.

And so what have they been doing on their approach to the moon over the last 145 days and where are the images taken by their cameras.

Some say that the cameras are not that good, but even a cheap 12megapixel digital camera can take snaps of the approach and they have nothing else (that we know of) to send back while they are getting there.

The gravity measurements should completely map the internal structure of the Moon but what will they release to the scientists of the world if the results are .... awkward or controversial?

How do they get these spacecraft flying along so precisely as has been reported above? Only if you bolted them together would you get this level of accuracy. That in itself is a mystery worth delving into.

Originally posted by Illustronic
What is interesting about the tandem spacecrafts is the accuracy in their flight path around the moon to make these measurements, described as being able to orbit at a distance from each other to the point of not deviating by more than the distance of a human red blood cell.

No, the flight path is not that accurate. The ranging system between the two craft are precise enough to measure a change in distance with that accuracy. They will, by way of necessity, deviate in distance from each other by far more than that. But given how accurately their orbits can be determined, the ranging system will allow a very precise measurement of how much of the change in distance is due to the local gravity field.

Thanks for posting this. I totally forgot about this. Cheers.
S&F