NASA extends life of MESSENGER Mercury probe

Posted by Emma Woollacott

NASA's decided to extend the MESSENGER mission for an extra year of orbital operations at Mercury.

The MESSENGER probe launched on August 3, 2004, and became the first spacecraft to orbit the planet on March 18, 2011. Its primary mission was scheduled to end on March 17 next year.

"We are still ironing out the funding details, but we are pleased to be able to support the continued exploration of Mercury," says NASA MESSENGER program scientist Ed Grayzeck.

Messenger's already revolutionized knowledge about Mercury, and extending the mission will enable ot to answer several questions which have arised because of those discoveries.

"During the extended mission we will spend more time close to the planet than during the primary mission, we’ll have a broader range of scientific objectives, and we’ll be able to make many more targeted observations with our imaging system and other instruments," says Solomon.

"MESSENGER will also be able to view the innermost planet as solar activity continues to increase toward the next maximum in the solar cycle. Mercury’s responses to the changes in its environment over that period promise to yield new surprises."

Scientists want to discover the sources of surface volatiles on Mercury, and how late into Mercury’s history volcanism persisted.

Also on the list of questions is how Mercury's long-wavelength topography changed with time and the origin of localized regions of enhanced exospheric density at Mercury.

Finally, they want to know how the solar cycle affects Mercury’s exosphere and volatile transport, along with the origin of its energetic electrons.

"Advancements in science have at their core the evaluation of hypotheses in the light of new knowledge, sometimes resulting in slight changes in course, and other times resulting in paradigm shifts, opening up entirely new vistas of thought and perception," says MESSENGER project scientist Ralph McNutt.