Thursday, April 30, 2015

NASA's MESSENGER Spacecraft Crashes Into Mercury


The MESSENGER spacecraft has crashed onto Mercury at about 8,750 mph and created a new crater on the planet’s surface, NASA announced today.

Mission controllers confirmed NASA’s MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft impacted the surface of Mercury, as predicted, at 3:26 p.m. EDT today.

“Going out with a bang as it impacts the surface of Mercury, we are celebrating MESSENGER as more than a successful mission,” said John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington. “The MESSENGER mission will continue to provide scientists with a bonanza of new results as we begin the next phase of this mission--analyzing the exciting data already in the archives, and unravelling the mysteries of Mercury.”

MESSENGER’s lonely demise on the small, scorched planet closest to the sun went unobserved because the probe hit the side of the planet facing away from Earth, so ground-based telescopes were not able to capture the moment of impact. Space-based telescopes also were unable to view the impact, as Mercury’s proximity to the sun would damage optics.

MESSENGER’s last day of real-time flight operations began at 11:15 a.m. Thursday, with initiation of the final delivery of data and images from Mercury via a 230-foot (70-meter) DSN antenna located in Madrid, Spain. After a planned transition to a 111-foot (34-meter) DSN antenna in California, at 2:40 p.m., mission operators later confirmed the switch to a beacon-only communication signal at 3:04 p.m.

MESSENGER was launched on August 3, 2004, and began orbiting Mercury on March 17, 2011. Although it completed its primary science objectives by March 2012, the spacecraft’s mission was extended two times, allowing it to capture images and information about the planet in unprecedented detail.

On Tuesday, NASA successfully executed the last of seven daring orbit correction maneuvers that kept MESSENGER aloft long enough for the spacecraft’s instruments to collect critical information on Mercury’s crustal magnetic anomalies and ice-filled polar craters, among other features. After running out of fuel, and with no way to increase its altitude, MESSENGER was finally unable to resist the sun’s gravitational pull on its orbit. 

“Today we bid a fond farewell to one of the most resilient and accomplished spacecraft to ever explore our neighboring planets,” said Sean Solomon, MESSENGER’s principal investigator and director of Columbia University’s Lamont-Doherty Earth Observatory in Palisades, New York. “A resourceful and committed team of engineers, mission operators, scientists, and managers can be extremely proud that the MESSENGER mission has surpassed all expectations and delivered a stunningly long list of discoveries that have changed our views--not only of one of Earth’s sibling planets, but of the entire inner solar system.” 

Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington