Exploration of Mercury - MESSENGER

MESSENGER

MESSENGER is a NASA probe in orbit of Mercury. MESSENGER stands for MErcury Surface, Space ENvironment, GEochemistry, and Ranging. It was launched from Cape Canaveral on August 3, 2004, after a two-day delay due to bad weather. It took the probe about six and a half years before it entered orbit around Mercury. In order to correct the speed of the satellite it undertook several gravitational slingshot flybys of Earth, Venus and Mercury. It passed by the Earth in February 2005 and then Venus in October 2006 and in October 2007. Furthermore the probe made three passes of Mercury, one in January 2008, one in October 2008 and one in September 2009, before entering orbit in 2011. During these flybys of Mercury, enough data was collected to produce images of over 95% of its surface. MESSENGER uses a “chemical bi-propellant system both to reach Mercury and brake into orbit”. MESSENGER's scheduled orbital insertion took place successfully on March 18, 2011. The mission is scheduled to end sometime in 2012, when there will no longer be enough fuel to maintain the probe's orbit.

The information collected by MESSENGER will be used to try to answer six questions about Mercury:

1. Why is the planet so dense?
2. What is Mercury's geologic history?
3. What is the structure of Mercury's core?
4. What is the nature of Mercury's magnetic field?
5. What are the unusual materials at Mercury's poles?
6. What volatiles are important on Mercury?”