7 July 1999
For Immediate Release
APL-Managed Mission to Mercury Selected for NASA Discovery Program Flight
The MESSENGER mission to investigate the planet Mercury - led by Principal Investigator Sean C. Solomon of the Carnegie Institution of Washington, Washington, D.C., and managed by The Johns Hopkins University Applied Physics Laboratory (JHU/APL), Laurel, Md. - has been selected by NASA as one of two new Discovery Program missions.
JHU/APL will design and build the MErcury Surface, Space ENvironment, GEochemistry and Ranging (or MESSENGER) spacecraft, which will be the first spacecraft to visit the closest planet to the sun in more than three decades. Scheduled for launch in 2004, MESSENGER will flyby Mercury twice in 2008 to gather data to guide the next step: a year-long orbit to conduct detailed scientific studies of the planet beginning September 2009.
"Understanding Mercury and the forces that shaped it is fundamental to understanding other terrestrial planets and their evolution," says JHU/APL project manager Max R. Peterson.
Seven miniaturized instruments aboard MESSENGER will attempt to peel back Mercury's veil of mystery, answering such key scientific questions as: Why is Mercury so dense, What are the characteristics and dynamics of its thin atmosphere and Earth-like magnetosphere, and What is the nature of the planet's mysterious polar caps?
JHU/APL project scientist Ralph L. McNutt Jr. says in addition to its harvest of scientific information, the $286 million MESSENGER mission has the potential to develop new technologies that can be transferred to industry.
For more information, visit Web site: sd-www.jhuapl.edu/MESSENGER/
The Applied Physics Laboratory (APL) is a not-for-profit laboratory and independent division of The Johns Hopkins University. APL conducts research and development primarily for national security and for nondefense projects of national and global significance. APL is located midway between Baltimore and Washington, D.C., in Laurel, Md.
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The Mercury Surface, Space Environment, Geochemistry and Ranging mission, or Messenger, will carry seven instruments into orbit around the closest planet to the Sun. It will send back the first global images of Mercury and study its shape, interior and magnetic field. Dr. Sean Solomon of the Carnegie Institution, Washington, DC, will lead Messenger.
The Deep Impact mission will send a 1,100-pound (500-kilogram) copper projectile into comet P/Tempel 1, creating a crater as big as a football field and as deep as a seven-story building. A camera and infrared spectrometer on the spacecraft, along with ground-based observatories, will study the resulting icy debris and pristine interior material. Dr. Michael A'Hearn will lead Deep Impact from the University of Maryland in College Park.
"These low-cost missions are both fantastic examples of the creativity of the space science community," said Dr. Edward Weiler, associate administrator for space science at NASA Headquarters in Washington, DC. "Messenger is a flagship-quality effort that, in tandem with a separate Pluto mission, enables us to seize the opportunity to complete our historic initial reconnaissance of the Solar System. Deep Impact presents a special chance to do some truly unique science, and it is a direct complement to the other two comet missions already in the Discovery Program."
Messenger, to be launched in spring 2004, will be NASA's first mission to Mercury since the Mariner 10 flybys in 1974 and 1975, which provided information on only half the planet. Its challenging flight plan begins with two Venus flybys, then two Mercury flybys in January and October 2008 and a subsequent orbital tour of Mercury beginning in September 2009.
Among Messenger's goals will be to discover whether Mercury has water ice in its polar craters. The cost of Messenger to NASA is $286 million. It will be built and managed by the Johns Hopkins University's Applied Physics Laboratory, Laurel, MD. Further information about the mission is available on the Internet at:
Deep Impact will be launched in January 2004 toward an explosive July 4, 2005, encounter with P/Tempel 1. It will use a copper projectile because that material can be identified easily within the spectral observations of the material blasted off the comet by the impact, which will occur at an approximate speed of 22,300 mph (10 kilometers per second.) The total cost of Deep Impact to NASA is $240 million. Deep Impact will be managed by NASA's Jet Propulsion Laboratory in Pasadena, CA, and built by Ball Aerospace in Boulder, CO.
NASA selected these missions from 26 proposals made in early 1998. The missions must be ready for launch no later than Sept. 30, 2004, within the Discovery Program's development cost cap of $190 million in Fiscal 1999 dollars over 36 months and a total mission cost of $299 million.
The Discovery Program emphasizes lower-cost, highly focused scientific mission. NASA has developed six other Discovery Program missions. Two have completed their primary missions, two are operational and two more are under development: