08.03.2006
Today marks the second anniversary of MESSENGER's launch. "It's still more than four and a half years to Mercury Orbit Insertion in March 2011, and there are many milestones between now and then," says Dr. Sean C. Solomon, of the Carnegie Institution of Washington, who leads the mission as principal investigator. "But it's worth pausing for a few moments today to appreciate how far we've come."
And just how far has it traveled since its Aug. 3, 2004, launch from Cape Canaveral Air Force Station, FL? The spacecraft is currently 1.285 astronomical units (AU) distant from the Earth (1 AU equals 93 million miles). Since lift off MESSENGER has traveled nearly 1.2 billion miles in its orbit around the Sun. To track MESSENGER's journey, go online to http://messenger.jhuapl.edu/whereis/index.php.
"It's been a busy two years," says MESSENGER Mission Operations Manager Mark Holdridge, of the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, MD. "We've been by Earth and now we are headed for Venus, another major milestone in this mission."
MESSENGER team members have been running tests all summer to make sure the spacecraft will operate as intended during the Venus flyby - the first of two swings past the clouded planet -scheduled for Oct. 24, 2006. There will be a 57-minute solar eclipse during that operation. So on Aug. 11, engineers will turn the spacecraft solar panels edge-on to the Sun and discharge the battery, much in the same manner that the power system will function during the Venus flyby, to verify that the system will respond appropriately.
Two weeks later, on Aug. 21, engineers will conduct a "star-poor" region test, pointing the spacecraft's star tracker in a region of the sky that might be utilized during the Venus operations Holdridge says a similar test was conducted on July 26, "and we got a positive result from that test; the preliminary results look good."
All in all, Holdridge says, all systems are functioning very well. "The spacecraft is very healthy, and the team is working hard to make this first flyby of Venus a success!"
For encounter details and graphics associated with the October maneuver, go online to http://messenger.jhuapl.edu/the_mission/MESSENGERTimeline/VenusFlyby1.html
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