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Posts Tagged ‘orbit’

Orbiting Mercury only to have a scare with Mariner showing up again.  A close friend and team member (The Electric Pole) e:mailed me:

I just got a message about MESSENGER from Jim Raines, see the link below. This is really unbelievable that Mariner should show up.  I wonder what the separation distance was between MESSENGER and Mariner.  That would be a bizarre fate to make it into orbit only to be smashed to bits by the only derelict spacecraft within 80,000,000 miles.

This is like a guy dumping his girlfriend as if she were a post-coitus $20 hooker and then when she gets a new boyfriend he suddenly shows up to crash the party.  See the pic of Mariner taken by MESSENGER…

More info here:

http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2&image_id=448

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Hooray MESSENGER!

Yay!  MESSENGER successfully went into orbit around Mercury tonight.  An awful lot of us breathed a sigh of relief.  There are three options when approaching a planet like they did – (a) You match velocity and make a successful orbit, (b) You shoot on past, or (c) You make a magnificent crater on another planetary body.

The rockit scientists did just fine.  With an 8-9 minute lag in communications (one way), real-time control is impossible, so on autopilot the spacecraft executed a successful burn and decelerated pretty fast (without ABS, I might add) and went into it’s eccentric orbit.  They’re waiting for more telemetry but all signs look good.

From the APL site:

MESSENGER Begins Historic Orbit around Mercury At 9:10 p.m. EDT, engineers in the MESSENGER Mission Operations Center at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., received the anticipated radiometric signals confirming nominal burn shutdown and successful insertion of the MESSENGER probe into orbit around the planet Mercury.

The spacecraft rotated back to the Earth by 9:45 p.m. EDT, and started transmitting data. Upon review of these data, the engineering and operations teams confirmed that the burn executed nominally with all subsystems reporting a clean burn and no logged errors.

MESSENGER’s main thruster fired for approximately 15 minutes at 8:45 p.m., slowing the spacecraft by 1,929 miles per hour (862 meters per second) and easing it into the planned eccentric orbit about Mercury. The rendezvous took place about 96 million miles (155 million kilometers) from Earth.

I’ll post a pic in a while of me sitting next to an engineering model of the FIPS instrument (it is attached to the EPPS instrument on MESSENGER).  We were all damn near crazy once we finished the fabrication of parts and built the thing up, but we did it in just under a year.

Here is a picture of a handsome little fella who I happen to know very well standing next to an engineering model of FIPS.  It’s packed with all the gooey sciencey goodness that only Sparks can dream up, folks, and looks just like the thing on MESSENGER, too.  Well, except that the whole thing is alodined and the real thing is covered all over with MLI/ceramic-blanket stuff.  The blanket is like asbestos underwear – keeps the precious stuff from getting too toasty (and can keep your drinks from getting too cold, too).   It also keeps seagull droppings off the instrument.  Now, you may be tempted to say “Oh, that isn’t a seagull-protective cover!”  To which I respond: “How come?  Do you see ANY seagull droppings on the instrument?”

Franken-Boy standing next to honest-to-goodness hardware.

For a size reference, the cylindrical thing pointed up and to the left is the size of a coke can and the whole thing is lighter than a popcorn fart.  There’s so much crammed into that front section alone that it would make your head swim.  As one of the project heads (a Spark) was introducing me to another attendee he said “Well, if you’d known what you were in for you might not have come on board.”  And he was right, I might have run away like a scared little girl.  What a great group of folks though.  I think we all hated each other a bit towards the end but we got over it.

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Update:  Dream up a caption…

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From the JHU APL website…  The last sentence is the amazing one.  That is so close to the mark as to be awe-inspiring, at least it is to me.

Ten Days from Orbit Insertion

Ten days from now – on March 17 EDT – the MESSENGER spacecraft will execute a 15-minute maneuver that will place it into orbit about Mercury, making it the first craft ever to do so, and initiating a one-year science campaign to understand the innermost planet.

Starting today, antennas from each of the three Deep Space Network (DSN) ground stations will begin a round-the-clock vigil, allowing flight control engineers at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., to monitor MESSENGER on its final approach to Mercury.

At 10:40 a.m. this morning, the spacecraft began executing the last cruise command sequence of the mission.  This command load will execute until next Monday, when the command sequence containing the orbit-insertion burn will start.

“This is a milestone event for our small, but highly experienced, operations team, marking the end of six and one half years of successfully shepherding the spacecraft through six planetary flybys, five major propulsive maneuvers, and sixteen trajectory-correction maneuvers, all while simultaneously preparing for orbit injection and primary mission operations,” says MESSENGER Systems Engineer Eric Finnegan. “Whatever the future holds, this team of highly dedicated engineers (http://messenger.jhuapl.edu/moc/index.html) has done a phenomenal job methodically generating, testing, and verifying commands to the spacecraft, getting MESSENGER where it is today.”

The mission operations team now turns its attention to the final preparations for the insertion burn next week and establishing nominal operations for the primary mission. As with the last three approaches to Mercury, the navigation team and the guidance and control team have been successfully using the solar radiation of the Sun to carefully adjust the trajectory of the spacecraft toward the optimum point in space and time to start the orbit-insertion maneuver.

As of the most recent navigation report on February 22, the spacecraft was less than 5 kilometers and less than three seconds from the target arrival point

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I May Wet Myself…

Update:

What is this quote from?  (no google-peeking)

When I was a little kid my mother told me not to stare into the sun. So once when I was six, I did.

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YEARS after launch, it is almost time…

December 7, 2010

One Hundred Days until Mercury Orbit Insertion

One hundred days from now, MESSENGER will execute a 15-minute maneuver that will place the spacecraft into orbit about Mercury, making it the first craft ever to do so, and initiating a one-year science campaign to understand the innermost planet. It has already been 14 years since this mission was first proposed to NASA, more than 10 years since the project officially began, and over six years since the spacecraft was launched.   – JHU’s MESSENGER Website

So it’s been traveling since August 3, 2004 and now finally, in 2010 it’s only 100 days away.  At this time… 4.7 BILLION miles.  That’s a long ways without bathroom breaks.

Just the astrophysicist’s work in plotting the course that has been so dead-nuts on that he’s gotten awards for it is amazing, but the whole darned thing is cool.  It won’t be cool while it’s in a polar orbit around Mercury for a year, though.  It’ll be hot.  Damned hot.

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