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[Chicago Astronomer - Astro Joe]

NASA MESSENGER Mission

Artist's impression of the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft in orbit at Mercury. MESSENGER launched from Cape Canaveral Air Force Station, Fla., on Aug. 3, 2004, and will begin a yearlong orbital study of Mercury in March 2011. Though the Sun is up to 11 times brighter at Mercury than we see on Earth and surface temperatures can reach 450 degrees Celsius (about 840 degrees Fahrenheit), MESSENGER's instruments will operate at room temperature behind a sunshade of heat-resistant ceramic fabric. The spacecraft will also pass only briefly over the hottest parts of the surface, limiting exposure to heat reradiated from the planet.

MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury, and the first space mission designed to orbit the planet closest to the Sun. The MESSENGER spacecraft launched on Aug. 3, 2004, and after flybys of Earth, Venus and Mercury will start a yearlong study of its target planet in March 2011. Dr. Sean C. Solomon, of the Carnegie Institution of Washington, leads the mission as principal investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft and manages the Discovery-class mission for NASA.

More here: messenger.jhuapl.edu/the_mission/index.html

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We are reaching in both directions, from Mercury to Pluto...excellent!

But, I think we should go at night when it's cooler...

[Chicago Astronomer - Astro Joe]

MESSENGER Executes Successful Flyby Test

On June 28, the MESSENGER team successfully tested the spacecraft and instrument commands planned for the Aug. 2 flyby of Earth – the gravity assist that starts the next leg of the spacecraft's journey toward Mercury. The Earth flyby will send the spacecraft toward Venus. The first of two Venus flybys is planned for October 2006.

The test involved a 180-degree rotation to turn MESSENGER's sunshade toward the Sun; then five hours and 40 minutes of activities involving three instruments – the Magnetometer, the Mercury Atmospheric and Surface Composition Spectrometer, and the Mercury Dual Imaging System. Another 180-degree rotation returned the spacecraft back to the sunshade-away-from-Sun orientation.

On the basis of this rehearsal of spacecraft activities planned near the Earth flyby, mission controllers at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, will make minor corrections to the final Earth flyby commands sent to the spacecraft. These corrections will maximize the quality of the science data collected for the flyby. In the coming weeks, the MESSENGER team will create the final Earth flyby command sequences, as well as perform additional simulations and reviews.
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We got space machines all over the place!

[Chicago Astronomer - Astro Joe]

Messenger spacecraft on way to Mercury

August 03, 2005
NASA's Messenger spacecraft swung by Earth for a Tuesday gravity assist that propelled it deeper into space on its long journey toward Mercury.

Scientists at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md., said Messenger's systems performed flawlessly.

The National Aeronautics and Space Administration said the spacecraft swooped around Earth, using the planet's gravity to significantly change its trajectory, sending it toward Venus for another gravity-assist flyby next year.

Launched Aug. 3, 2004, from Cape Canaveral, Fla., the solar-powered spacecraft is approximately 581 million miles into its 4.9-billion-mile voyage that includes 14 more loops around the sun.

Messenger will fly past Venus twice and Mercury three times before moving into orbit for a year-long science mission around Mercury.

"This Earth flyby is the first of a number of critical mission milestones during Messenger's circuitous journey toward Mercury orbit insertion," said Sean Solomon, the mission's chief scientist. "Not only did it help the spacecraft sharpen its aim toward our next maneuver, it presented a special opportunity to calibrate several of our science instruments."

Copyright 2005 by United Press International