NASA's MESSENGER spacecraft left home in Maryland today for Cape Canaveral, Fla., site of its scheduled July launch toward Mercury and the first study of that planet from orbit.
Secured in an air-conditioned moving van, MESSENGER set out from NASA's Goddard Space Flight Center in Greenbelt on March 9 and reached Kennedy Space Center/Cape Canaveral Air Force Station the next day. MESSENGER — short for MErcury Surface, Space ENvironment, GEochemistry, and Ranging — spent the past three months being baked, frozen, spun, shaken and probed in Goddard's test facilities, experiencing the conditions of launch and its upcoming five-year journey to the innermost planet.
Over the next several weeks, engineers from The Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., where MESSENGER was designed and built, will prepare the spacecraft for launch at the Astrotech Space Operations facility near Kennedy Space Center. Other team members will continue to test the spacecraft's key operating systems remotely from the MESSENGER Mission Operations Center at APL.
Set for a predawn launch aboard a Boeing Delta II rocket, during a 15-day launch period that opens July 30, MESSENGER will fly past Earth once, Venus twice and Mercury three times before starting its yearlong orbital study of Mercury in March 2011. The Earth flyby in July 2005 and the Venus flybys in October 2006 and June 2007 use the planets' gravity to guide MESSENGER toward Mercury's orbit. Mercury flybys in January 2008, October 2008 and September 2009 further tune MESSENGER's path and allow the spacecraft to gather data critical to planning the mission's orbital phase.
The compact 1.2-ton spacecraft features several defenses against the intense heat and bright sunlight at Mercury, including a ceramic-fabric sunshade and a heat-radiation system. The mission's orbit design will also keep MESSENGER cooler by allowing it to pass only briefly through heat reflecting off the hottest spots on Mercury's surface, where temperatures can exceed 840 degrees Fahrenheit (450 degrees Celsius).
MESSENGER is the next launch in NASA's Discovery Program of lower cost, highly focused space science investigations. Sean C. Solomon of the Carnegie Institution of Washington leads MESSENGER as principal investigator; APL manages the mission for NASA's Office of Space Science.
More information on MESSENGER's journey and science mission is available at http://messenger.jhuapl.edu.