[meteorite-list] MESSENGER's Cameras Capture 100, 000th Image from Mercury Orbit

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu, 3 May 2012 11:11:48 -0700 (PDT)
Message-ID: <201205031811.q43IBmOY001769_at_zagami.jpl.nasa.gov>

http://messenger.jhuapl.edu/news_room/details.php?id=220

MESSENGER Mission News
May 3, 2012
http://messenger.jhuapl.edu/

MESSENGER's Cameras Capture 100,000th Image from Mercury Orbit

This week, MESSENGER's Mercury Dual Imaging System delivered the
100,000th image of Mercury since the spacecraft entered into orbit
around the planet on March 18, 2011. The instrument - one of seven
aboard the spacecraft - has globally mapped the planet in
high-resolution monochrome images and in color images through eight of
its color filters, uncovering a new view of Mercury and shedding light
on the planet's geologic history.

"That our inventory of orbital images of Mercury is now expressed in six
figures constitutes an important footnote in the history of solar system
exploration," offers MESSENGER Principal Investigator Sean Solomon, of
the Carnegie Institution of Washington. "The MESSENGER mission has at
last provided us a view of the innermost planet that is fully global,
multispectral, and at a range of illumination conditions. Moreover, we
are steadily building a library of targeted high-resolution images that
allow us to view features and discern geological processes in
unprecedented detail."

Because of Mercury's proximity to the Sun and its slow rotation,
designing an imaging system for an orbital mission presented quite a
challenge, says MDIS Instrument Engineer Ed Hawkins of the Johns Hopkins
University Applied Physics Laboratory (APL) in Laurel, Md.

"The sunshade protects the spacecraft from direct solar illumination,
but we knew it would constrain a camera's range of pointing," Hawkins
says. "So, we had to come up with a system that would be able to capture
the required observations of the planet, maintain the thermal safety
requirements and not jeopardize the safety of the spacecraft.

"We finally came up with the idea for a pivoting mechanism that gave the
instrument an extra degree of freedom, allowing it to obtain extra
observations even when the spacecraft - and the rest of the instruments
??? were facing away from the planet."

The system has exceeded the team's expectations, he says. "We obtained
images of Earth and Venus, but those were primarily to test
the instrument. We used fairly simple spacecraft pointing options and
exercised basic MDIS exposure control and compression options," he says.
But the instrument's performance during the first flyby of Mercury
in January 2008 was the first demonstration of the instrument's full
capabilities.

"When we received that first image after the first flyby, it confirmed
for us that the imaging system we designed was working, and since then
the camera has been operating flawlessly," he says.

Nori Laslo, MESSENGER's Deputy Payload Operations Manager and MDIS
Instrument Sequencer, says she can remember when this point "still
seemed eons away.

"To have now successfully completed our primary mission, entered our
extended mission, and surpassed 100,000 images is spectacular and really
speaks to the ability of the MESSENGER team to work as a unit to tackle
from all sides whatever challenges are encountered," says Laslo of APL.
"The team is made up of people with many different backgrounds,
including engineers, scientists, analysts, sequencers, flight
controllers, software developers, information technology specialists,
managers, and administrative support, among others. Everyone brings
different expertise and insight to the table. So the milestone of
100,000 images from orbit is really a group achievement, a product of
our combined efforts to make the MESSENGER mission a success."

The 100,000 images from Mercury's orbit constitute an important
milestone, says MDIS Instrument Scientist Nancy Chabot, of APL. But
there is still much more to come. "New images are returned from Mercury
orbit on nearly a daily basis, and scientists around the world are
studying these images to decipher Mercury's history and evolution."

Track the MESSENGER mission as MDIS begins to acquire the next 100,000
images from Mercury orbit by going online http://messenger.jhuapl.edu or
downloading the MESSENGER app <http://messenger.jhuapl.edu/epoapps/>.
------------------------------------------------------------------------
MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and
Ranging) is a NASA-sponsored scientific investigation of the planet
Mercury and the first space mission designed to orbit the planet closest
to the Sun. The MESSENGER spacecraft launched on August 3, 2004, and
after flybys of Earth, Venus, and Mercury will start a yearlong study of
its target planet in March 2011. Dr. Sean C. Solomon, of the Carnegie
Institution of Washington, leads the mission as Principal Investigator.
The Johns Hopkins University Applied Physics Laboratory built and operates
the MESSENGER spacecraft and manages this Discovery-class mission for NASA.
Received on Thu 03 May 2012 02:11:48 PM PDT