1. An overview of the MESSENGER spacecraft Joshua V. Nelson Chairman, SEDS-USA Note: All images contained in this presentation are courtesy NASA/JPL unless otherwise stated.

2. Overview: Why go? What will we accomplish? Spacecraft design Payload design Getting there Operations Follow up?

3. Why go now? Mariner 10, 1974 Mercury very difficult to get to! Follow-up deemed impossible with chemical rockets. What has changed since 1974? Discovery Mission selected 1999

4. The Discovery Missions NEAR Pathfinder Prospector Stardust GENESIS CONTOUR MESSENGER Deep Impact DAWN Kepler GRAIL

5. MESSENGER MErcury Surface Space ENviroment GEochemistry and Ranging mission.

6. Question asked of Messenger: Why is Mercury so dense? What is the geological history of Mercury? What characterizes Mercury's magnetic field? How is Mercury’s core structured? What are the reflective materials on the poles? What chemical processes maintain the composition of the exosphere?

7. The Spacecraft

9. Instrument Payload Mercury Dual Imaging System (MDIS) Gamma – Ray and Neutron Spectrometer (GRNS) X – Ray Spectrometer (XRS) Magnetometer (MAG) Mercury Laser Altimeter (MLA) Mercury Atmospheric and Surface Composition Spectrometer (MASC) Energetic Particle and Plasma Spectrometer Low, Medium, High Gain Antennae

10. Instrument Payload

11. Getting there Launch 3 August 2004 Earth flyby 2 August 2005 DSM-1 12 December 2005 Venus flyby 1 24 October 2006 Venus flyby 2 5 June 2007 DSM-2 17 October 2007 Mercury flyby 1 14 January 2008 DSM-3 17 March 2008 Mercury flyby 2 6 October 2008 DSM-4 6 December 2008 Mercury flyby 3 29 September 2009 DSM-5 29 November 2009 MOI 18 March 2011

12. Operations 1 year in orbit Minimal station keeping Figure credit S.C. Solomon et al.

13. Follow up ESA ( 2 for the cost of 1 ) –Mercury Planetary Orbiter –Mercury Magnetosphere Orbiter Will there be any future NASA probes?

14. References: Information drawn from: PTYS 411 Geology of the Solar System, Shane Byrne, Fall 07 Soloman, S.C. et al. “MESSENGER Mission Overview”. Space Science Review (2007) 131:3-39. © Springer Science+Business Media B.V. 2007. NASA / JPL / APL MESSENGER Mission homepage: http://messenger.jhuapl.edu/index.php accessed January 2008 http://messenger.jhuapl.edu/index.php