MESSENGER – The Other Courageous Spacecraft That Could
John Neumann for redOrbit.com – Your Universe Online
Eight years ago this month, in 2004, the MESSENGER space probe was launched on a six-and-a-half year, 4.9-billion mile journey to be the first spacecraft to orbit the planet Mercury. The leisurely cruise included 15 trips around the Sun, a flyby of Earth, two flybys of Venus, and three flybys of Mercury.
During its gravity assist swing-by of Earth, on August 2, 2005, Messenger´s cameras captured several hundred images of our planet. These images were sequenced into a video documenting the view from MESSENGER as it departed its home planet toward the inner Solar System.
In 2006, MESSENGER, which stands for MErcury Surface, Space ENvironment, GEochemistry, and Ranging, zipped just above the cloud deck of Venus for the first time and returned less than a year later in June 2007, in its first observation with all seven instruments turned on and operating collectively in full science-observing mode.
Also at that time, the spacecraft turned its wide-angle camera back to Venus and recorded a departure sequence that provided a spectacular salute to the mystery-shrouded planet while also acquiring valuable calibration data for the camera team.
MESSENGER also made history in January 2008, when it flew over a portion of Mercury that had never before been seen at close range with the probe´s cameras sending back over 1,200 images and its other instruments made the first spacecraft measurements of the planet and its environment since Mariner 10´s visit in 1975.
In March of last year, MESSENGER began the final phase of its mission and entered orbit around Mercury for a year-long campaign to perform the first global reconnaissance of the geochemistry, geophysics, geologic history, atmosphere, magnetosphere, and plasma environment of the solar system´s innermost planet.
“Our small spacecraft has been a hardy traveler,” says MESSENGER Principal Investigator Sean Solomon, of the Lamont-Doherty Earth Observatory at Columbia University.
“Across billions of miles, during more than 1,000 orbits about the planet with the greatest extremes in surface temperature, and in the face of streams of energetic particles from an increasingly active Sun, Messenger has continued to surpass expectations. Mercury, too, has continued to surprise the scientific community, and the MESSENGER team looks forward to learning more about one of the nearest yet least studied worlds.”