Mission: MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER)
Launch Date: August 3, 2004
Launch Time: 2:15:56 a.m. EDT
Launch Vehicle: Delta II Heavy
Launch Pad: 17-B

NASA's MESSENGER mission was designed to understand the forces that have shaped the planet Mercury. With MESSENGER's discoveries, scientists will better understand how the planet was formed, how it evolved and how it interacts with the Sun.

Mercury, Venus, Earth, and Mars are called terrestrial (rocky) planets. Understanding this "end member" among the terrestrial planets is vital to knowing more of how our own Earth was formed.

Researchers are looking to answer several crucial questions such as: Why is Mercury so dense? What is the geologic (rock) history of Mercury? And what is the structure of Mercury's core? MESSENGER is commissioned to investigate the answers to these and other important questions.

Gravity assist by the planet Venus and three Mercury flybys, along with several course correction maneuvers, will position MESSENGER to start its orbit in March 2011.

MESSENGER is scheduled to stay in orbit at Mercury for one Earth year, finishing its data collection in March 2012.

MESSENGER was the seventh mission selected for NASA's Discovery Program, the agency's innovative approach to low-cost, scientifically focused planetary missions.

MESSENGER has been built for NASA by the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.

03 Aug 2004
NASA's MESSENGER -- set to become the first spacecraft to orbit the planet Mercury -- launched today at 2:15:56 a.m. EDT aboard a Boeing Delta II rocket from Cape Canaveral Air Force Station, Fla.
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02 Aug 2004
The launch of NASA’s MESSENGER spacecraft was postponed this morning due to lightning potential from residual clouds that were associated with Tropical Storm Alex. The launch has been rescheduled for Tuesday, August 3 at 2:15:56 a.m. EDT at the opening of a 12-second launch window.
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27 July 2004
The NASA Direct! Web site is featuring two webcast events and countdown coverage for MESSENGER. Programming begins July 29 at 2 p.m. EDT and concludes after launch, currently scheduled for August 2 from Cape Canaveral Air Force Station in Florida.
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Note to Editors - A prelaunch press conference will be held at the NASA News Center at KSC on Saturday, July 31, at 1 p.m. EDT. MESSENGER Mission Science Briefing and all related information will be provided.
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19 July 2004
Next Stop: The Launch Pad. The MESSENGER spacecraft is now firmly attached to the third stage of its Delta II launch vehicle in anticipation of the launch window that opens at 2:16 a.m. (EDT) on August 2.
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15 July 2004
NASA is sending a Messenger to Mercury. NASA's first trip to Mercury in 30 years starts on August 2 with the launch of the MESSENGER spacecraft from Cape Canaveral.
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14 July 2004
A pre-launch press briefing will be held on Thursday, July 15, at 1 p.m. EDT at NASA Headquarters and broadcast on NASA TV.
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12 July 2004
MESSENGER media opportunity set for Wednesday, July 14, at 10:15 a.m..
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01 July 2004
The MESSENGER spacecraft receives its Sun Catchers.
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29 June 2004
MESSENGER's launch has been rescheduled and is now targeted to occur August 2.
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24 March 2004
The planned May launch of MESSENGER has been rescheduled for no earlier than July 30.
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10 March 2004
MESSENGER spacecraft arrives in Florida to begin final preparations for launch.
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NASA's MESSENGER Web Site
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Johns Hopkins Univerity's MESSENGER Web Site
Learn the background and details of the upcoming mission.
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The Delta Launch Vehicle
Look up information about Boeing's Delta II launch vehicle.
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