Doesn't seem to be any ongoing discussion of this probe headed toward Mercury.
Thought I'd start one just to keep anyone interested informed. Doing a countdown is somewhat meaningless considering that this probe is actually counting UP at this point.

Why does NASA insist on making acronyms? Considering the role of Mercury in the ancient Pantheon, isn't simply Messenger a good enough name? Did they have to make it into a very awkward acronym (MErcury Surface, Space ENvironment, GEochemistry and Ranging)?

Anyway, it is presently in an eliptical orbit that will bring it across Earth's orbit within the next few weeks before heading inward and getting a gravity brake(?) from Venus later this year.

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Keeper of the Jabberwock

launched August 2004

Mercury, here we come... again.

Mercury orbit insertion will be on the 18th of March 2011, starting a year-long orbital mission.

I'm watching this mission, but there's not much to say. It is interesting that it will be outside the Earth's orbit for the last time soon. Then on to Venus for an uneventful flyby. As far as I know, no science is planned for this pass.

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Forming opinions as we speak

It's got a very long flight to get to Mercury. APL seems to be specializing in missions requiring a lot of patience.

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Everything I need to know I learned through Googling.

Mercury is approximately as far from the Sun as the Earth. It will be just outside of Earth orbit for the next few weeks.

edited: Dang it, meant Messenger!

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Keeper of the Jabberwock

I think you mean that Messenger is just outside Earth's orbit.

Messenger actually gets to Mercury in 2008, but has several fly-bys as the orbit adjusts so that it can get into orbit around Mercury rather than the Sun. There is a good diagram on the project site.

Nineplanets also has a good page on Mercury itself.

Well, read further into the MESSENGER updates (nearly typed Mercury again) and discovered that it has travelled one billion (1,000,000,000) kilometers with another 4B to go until it reaches MERCURY orbit.

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Keeper of the Jabberwock

great going !

but still a long way to travel ( orbit on 18th of March 2011 )

Awesome Earth flyby movie

(Courtesy of the BA's blog.)

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Everything I need to know I learned through Googling.

Didn't this already get posted to the board last year?

CJSF

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Two years ago moved from my town
I was looking up past the city lights
But the city lights got in my way

See the constellation ride across the sky
No cigar, no lady on his arm
Just a guy made of dots and lines

-from "See The Constellation"
by They Might Be Giants

Yep.

But - quickly contriving an excuse - don't you think it's worth a second visit?

__________________
Everything I need to know I learned through Googling.

It appears that Messenger will be at its farthest point from the Sun within the next week or so. After that, it will encounter Venus and be brought into an orbit inside of Earth.

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Keeper of the Jabberwock

The reason it's taking so long is because of the gravity assists in its trajectory; that saves on bulk of rocket.

The first spacecraft to go to Mercury, Mariner 10, got a gravity assist from a flyby of Venus; that spacecraft flew by Mercury three times.

MESSENGER is getting several. It already got one from the Earth, and it will get two from Venus and three from Mercury.

As to the ESA's upcoming Bepi Colombo mission, it will also be using gravity assists from the Earth, the Moon, and Mercury, though I have not been able to find many details on that. That may be why it is expected to take 4.5 years to travel to Mercury.

The APL website is somewhat unclear at the precise point of aphelion, but it appears that Messenger has reached it. Sometime in the last week of May, it should cross Earth orbit for the last time. It will cross Venus orbit in October close enough to the planet to slow it down the orbiter a bit.

Edit: The APL website added a new orbit today, so I assume that, on 2 May 2006, it began falling back to the Sun.

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Keeper of the Jabberwock

The Messenger probe to Mercury is currently further from the Sun than the Earth is. That however is about to change for the last time. In the next few days, Messenger's path will take it inside the Earth's orbit for a reverse-slingshot encounter with Venus (144 days from now) which will take energy from it's orbit and drop Messenger's perihelion significantly.

Messenger is intended to be the first probe to orbit Mercury.

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Forming opinions as we speak

Messenger is crossing Earth orbit for the final time. After its encounter with Venus this fall, it will be permanently within Earth orbit.

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Keeper of the Jabberwock

Over the weekend, Messenger crossed the halfway point between Earth orbit and Venus orbit.

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Keeper of the Jabberwock

I wonder if the Mesenger cameras can be used to scan looking for asteroids with aphelions inside the Earth's orbit. We know very little about this population.

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Forming opinions as we speak

Anyone have any updates or link's to where i can find it's progress?

NM googled and found http://messenger.jhuapl.edu/news_room/index.html

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Everything I need to know I learned through Googling.

Happy Anniversary, MESSENGER!

Launch plus 2 years and still less than a third of the way enroute.

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Everything I need to know I learned through Googling.

Any chance of MESSENGER seeing Vulcanoids?

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There is a growing tendancy to think of Man as a rational, thinking being, which is absurd.- Marvin the Martian.

It's gotten to the point where careful investigation is needed just to tell parody from reality. I think that means reality is broken.- Noclevername.

Wow, barely a few hours back from my vacation and I notice a major milestone. Messenger is crossing Venus orbit today. It will be inside Venus' orbit until its encounter with the planet in October.

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Keeper of the Jabberwock

That's the Delta II sounding rocket for you.

50 yr.old R-7 places two tons more in orbit than that blue-painted stomp rocket.

On the other hand, the Child of Energiya has already sent its Hail Mary to Pluto out past Ceres.

"Oh, what a difference!" Sing it with me now.

Dan Goldin's punishment in Hell:

"I will not underspend on launch vehicles while overthinking payloads."
"I will not listen to SFF, Bell or Cowing..."

"Praise the Son of Zenit."

Messenger is at its closest approach to the Sun for this orbit. They have fired its manuevering rockets to slightly correct its course.

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Keeper of the Jabberwock

It is now four weeks until Messenger makes its first flyby of Venus. Prepare yourself for some spectacular images of mostly undifferentiated cloud-cover.

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Forming opinions as we speak

^
Maybe not. IIRC, Venus will be near conjunction; I've heard that little or no science will be done on this flyby. The next one is a different story, though.

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"Call me old-fashioned, but I think fire is magic. And it scares me a lot."

--The State

This morning the countdown to Venus encounter dropped below 10 days. There will be no science done on this encounter. I'm not even sure they are taking any pictures.

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Keeper of the Jabberwock

They won't. Too risky.

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Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.
-- Richard Feynman

Messenger is through 1/3 of its expected travel time to Mercury orbit insertion.

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Keeper of the Jabberwock