MESSENGER: 1,000+ Orbits and Counting…

The above image was released December 1, 2011 by the NASA MESSENGER mission. It shows an orthographic projection of a global mosaic of the planet Mercury, centered at 0°N, 270°E. Beethoven basin is visible towards the southwest. Kuiper crater appears brighter than its surroundings towards the eastern edge near the equator. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington 

Back on June 22nd, NASA’s MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission completed its 1,000th orbit of the planet Mercury.

The MESSENGER spacecraft entered orbit around Mercury in mid-March of 2011, after traveling more than 15 times around the sun through the inner solar system and completing six planetary flybys. That means it took just over 15 months to reach this milestone. Of course, the orbits are fast because MESSENGER is so close to Mercury, and its going to get closer. In April, the period was reduced from 12 hours to 8 hours, so it will take MESSENGER only 11 months to complete the next 1,000 orbits.

During MESSENGER’s primary mission, which concluded on March 17th, the spacecraft and mission team performed the first global reconnaissance of the geochemistry, geophysics, geologic history, atmosphere, magnetosphere, and plasma environment of Mercury. The spacecraft is now one-third of the way into a one-year extended mission that is building on this knowledge to address new questions raised by the initial orbital observations.

The mission team is very proud of their little orbiter, having to constantly endure high temperatures and increasingly frequent streams of solar energetic particles. And with the primary mission completed successfully, the team members look forward to the new science that MESSENGER will glean from the closest planet in our solar system.

For example, in the first week of May, MESSENGER’s Mercury Dual Imaging System (MDIS) delivered the 100,000th image of Mercury since arrival. MDIS — one of seven instruments 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.

We extend our hearty congratulations to the great achievements of MESSENGER. We salute the spacecraft and mission team, and we look forward to the discoveries to come.

And now, the mission particulars…

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 entered orbit about Mercury on March 17, 2011 (March 18, 2011 UTC), to begin a yearlong study of its target planet. MESSENGER’s extended mission began on March 18, 2012. 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. To learn more about Mercury and MESSENGER, visit messenger.jhuapl.edu .

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