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.

Overview:

• Why go? • What will we accomplish?• Spacecraft design• Payload design• Getting there• Operations• Follow up?

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

The Discovery Missions

• NEAR• Pathfinder• Prospector• Stardust• GENESIS• CONTOUR• MESSENGER• Deep Impact• DAWN • Kepler• GRAIL

MESSENGER

MErcury

Surface

Space

ENviroment

GEochemistry and

Ranging mission.

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?

The Spacecraft

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

Instrument Payload

Getting there

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

Operations

•1 year in orbit

•Minimal station keeping

Figure credit S.C. Solomon et al.

Follow up

• ESA ( 2 for the cost of 1 )– Mercury Planetary Orbiter – Mercury Magnetosphere Orbiter

Will there be any future NASA probes?

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