JMEX: The Jupiter Magnetospheric Explorer

Comparative Magnetospheres from Earth Orbit

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JMEX addresses major issues in NASA's Sun-Earth Connections theme through a comparative magnetospheres study of the Jupiter-Io System. JMEX will answer four fundamental questions:

1. Which processes in Jupiter's magnetosphere are influenced by the solarwind (as at Earth), and which processes are controlled by Io?
2. Does plasma production depend on Io's volcanic activity, or is it controlled by Io's magnetospheric interaction?
3. How does the magnetosphere response to internal plasma production?
4. What are the causes of Jupiter's three aurora? How are these processes similar to Earth's and how do they differ?

JMEX Observations

The Jupiter-Io system is highly variable and strongly coupled, so JMEX takes a unique approach with:

1. Simultaneous, global, long-term measurements of Io, the plasma torus, and Jupiter's aurora.
2. An emphasis on discovering the cause-and-effect relationships between them.

Science Team

Science Payload

1. The FUV system (UVI) offers imaging and spectroscopy of Io, Jupiter's aurora and atmosphere in the 115-200 nm range.
2. The 50-cm FUV-optimized telescope yields £0.2" optical image quality.
3. An Image Motion Sensor enables innovative jitter mitigation through post-processing, providing £0.25"
   final image quality.
4. A 30-cm EUV telescope (EUVS) provides 64-114 nm spectral imaging of the Io plasma torus.

Mission Overview

1. JMEX is an Earth-orbiting UV observatory viewing Jupiter when Ž45� from the Sun and not occulted.
2. JMEX provides continuous, long-term observations of Jupiter's complex and dynamic system for two 9-month periods within the 24-month mission lifetime.
3. Guest Investigators may use JMEX's unique FUV and EUV capabilities when Jupiter is Ž45� from the Sun.
4. Mission operations are conducted by the University of Colorado with extensive student participation

Mission Summary

JMEX Spacecraft Characteristics

1. Ball's RS300 uses heritage structural design, along with flight-proven components to enable low-cost production of a highly-capable design with margins.
2. Reaction wheel vibration isolators reduce high frequency jitter.
3. Feedback from Image Motion Sensor provides real-time input to observatory pointing control.
4. 1-axis deployable solar panel provides high power margin throughout the mission.
5. Materials, processes, and handling provide a non-contaminating environment for UV optics.

Education & Public Outreach

1. Taps public excitement surrounding volcanoes and the northern lights, integrating JMEX science into both
   formal and informal venues.
2. Special emphasis on reaching underserved communities.
3. LASP leads E/PO in collaboration with the science
   team and the National Center for Atmospheric Research.

The JMEX Team

Mission Phases

JMEX: The Jupiter Magnetospheric Explorer