Location and Orbit
Missions to Mercury
References & Links
Mercury: Missions to the Planet
Only one space mission has ever visited Mercury, the Mariner 10. Launched in I passing by the planet three times, providing the only close-up pictures of Mercury ever taken, and the only significant non-terrestrial pictures since the long-range shots taken by the lunar-based . The expedition was the first probe to use planetary gravity to accelerate, and discovered Mercury's magnetic field. The Mariner's pictures cover nearly sixty percent of the planet's surface and are to date the only close-range data collected.
That may change. The NASA's Discovery Program, a series of exploratory missions that included the Mars Pathfinder mission, has chosen from among twenty-six proposals to send off the Messenger mission. The Mercury Messenger (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is scheduled to blast off in 2004, carrying with it a wide range of probes and sensors. Quite possibly its most important task will be to examine the hollows of Mercury's craters for ice, which was detected via radio on Earth in 1992. Operating under the auspices of NASA, Johns Hopkins University will oversee the $286 million dollar program.
Summary of Past Missions