Technology Requirements

• Thermal control and survivability
• Advanced SEP [beyond NSTAR] or solar sail
• High-temperature solar array
• Lightweight instruments

• Origin and nature of the planetary magnetic field
• Magnetospheric structure and dynamics
• Magnetospheric plasma/regolith interaction
• Composition and sources of exosphere
• Surface composition
• Evidence of volcanic and tectonic activity
• Global early cratering history
• Planetary accretion near the Sun
• Observation of Sun's surface, corona, and energetic particles

Mission Description

• Delta II launch in 2002
• 30-kilogram payload
• 2.3-year flight (includes Venus and Mercury gravity assists using SEP)
• 1-year mission
• 8-hour polar orbit (200 km by 10,000 km)
• Spacecraft accommodates nadir-pointed and spinning instruments.
• Significant heritage from preceding JPL missions is assumed.

Measurement Strategy

• Magnetic and gravity field measurements
• In-situ particles and fields measurements
• UV measurements of atmospheric composition
• Multispectral map of surface geology
• Lidar altimetry
• Visible/IR/UV remote sensing
• Gamma-ray spectroscopy
• Neutron detection/spectroscopy
• Precision tracking/ranging