# Presentation: 352408

## Geospace Magnetospheric and Ionospheric Neutral Imager (GEMINI)

-  **Measurement Strategy**
- Two high altitude spacecraft with global ENA and EUV imaging magnetosphere, and high resolution global spectroscopic FUV imaging of the I-T system
- Ground radar measurements coordinated with space-based sensors
-  **Minimum Technology Design**
- No “enabling” technology required

-  **Science Objectives**
- Determine dynamic coupling between ionosphere and magnetosphere
- Determine how magnetospheric energy is dissipated in the Ionosphere-Thermosphere (I-T) system
- Determine the important feedback mechanisms from the I-T system to the magnetosphere
- Determine global magnetospheric dynamics
-  **Mission Description **
- Mission Design
- 2 High Altitude Spacecraft (HAS) in 8Re circular near-polar orbit
- Ground-based radar network covers 30 to 90 deg north and south latitudes
- 2 year life
- Payload
- 3 FUV, 1 EUV, 1 ENA Imaging instruments per S/C, nadir pointing with yaw about nadir
- ~10 ground radar installations with 2 antennas each

## JUSTIFICATION
The Terrestrial ionosphere, plasmasphere, ring current and radiation belt  are components of one coupled system, that can only be understood by simultaneous and continuous global imaging.
EXPLORATION
Exploration rests on a solid understanding of our immediate space environment
how the inner magnetosphere affects the ionosphere-thermosphere system
how the inner magnetosphere controls the radiation belt dynamics
Stepping stone for system approach to planetary environments in general
SSSC OBJECTIVE
One of the overarching objectives of the 2003 Roadmap was to “Understand the Sun, Heliosphere and Planetary Environments as a Single Connected System”. GEMINI is taking this approach to the Terrestrial inner magnetosphere system.
GEMINI addresses all three objectives:
Understand the changing flow of energy and matter throughout the Sun, heliosphere, and planetary environments.
Ability to image the transport of plasma of different regimes and their interrelationships. Specifically plasma sheet and ring current during storms and substorms and their effect on the ionosphere/thermosphere system.
Explore the fundamental physical processes of space plasma systems.
Ability to explore the global effects of physical processes such as wave-particle scattering.
Define the origins and societal impacts of variability in the Sun-Earth connection.
Ability to determine when storms are most geoeffective.
DECADAL SURVEY (Executive Summary)
Discussed as the Stereo Magnetospheric Imaging (SMI) mission. 
The Decadal Survey emphasizes an “Integrated Research Strategy” (p. 4).
GEMINI is taking a systems approach capturing the simultaneous, global and continuous response of the ionosphere/thermosphere-inner magnetosphere system.
SMI is one of the recommended missions (Table ES.1)
Can be a core part of the “centralized database” (p. 15) of extreme space weather responses on a continuous basis.
Has a natural place in publication and outreach. Strength of images.
SYNERGIES
Global ENA and EUV imaging from a similar orbit is recommended in the LWS GMDT report. Both the ring current (knowledge about substorm injection propagation, electric  and magnetic fields and EMIC wave generation and interactions) and the plasmasphere (EMIC and chorus mode wave, electric fields) are now appreciated to hold necessary clues for radiation belt dynamics. Therefore, the addition of GEMINI to RBSP would add a critical element to the LWS Program measurement and science objectives.
DECISION POINT FOR FUTURE PLANS
Should be an approach to a terrestrial space weather monitoring system.
Decides how exploration of planetary space environments can most effectively be conducted. Good example is the proven strength of ENA imaging in the Saturnian system by Cassini.

- The Terrestrial ionosphere, plasmasphere, ring current and radiation belt  are components of one coupled system, that can only be understood by simultaneous and continuous global imaging.
**EXPLORATION**
- Exploration rests on a solid understanding of our immediate space environment
- how the inner magnetosphere affects the ionosphere-thermosphere system
- how the inner magnetosphere controls the radiation belt dynamics
- Stepping stone for system approach to planetary environments in general
**SSSC OBJECTIVE**
- One of the overarching objectives of the 2003 Roadmap was to “*Understand the Sun, Heliosphere and Planetary Environments as a Single Connected System***”**. GEMINI is taking this approach to the Terrestrial inner magnetosphere system.
- GEMINI addresses all three objectives:
- Understand the changing flow of energy and matter throughout the Sun, heliosphere, and planetary environments.
- Ability to image the transport of plasma of different regimes and their interrelationships. Specifically plasma sheet and ring current during storms and substorms and their effect on the ionosphere/thermosphere system.
- Explore the fundamental physical processes of space plasma systems.
- Ability to explore the global effects of physical processes such as wave-particle scattering.
- Define the origins and societal impacts of variability in the Sun-Earth connection.
- Ability to determine when storms are most geoeffective.
**DECADAL SURVEY (Executive Summary)**
- Discussed as the Stereo Magnetospheric Imaging (SMI) mission.
- The Decadal Survey emphasizes an “*Integrated Research Strategy*” (p. 4).
- GEMINI is taking a *systems approach *capturing the simultaneous, global and continuous response of the ionosphere/thermosphere-inner magnetosphere system.
- SMI is one of the recommended missions (Table ES.1)
- Can be a core part of the “*centralized database*” (p. 15) of extreme space weather responses on a continuous basis.
- Has a natural place in publication and outreach. Strength of images.
**SYNERGIES**
- Global ENA and EUV imaging from a similar orbit is recommended in the LWS GMDT report. Both the ring current (knowledge about substorm injection propagation, electric  and magnetic fields and EMIC wave generation and interactions) and the plasmasphere (EMIC and chorus mode wave, electric fields) are now appreciated to hold necessary clues for radiation belt dynamics. Therefore, the addition of *GEMINI *to* ****RBSP*** would add a critical element to the LWS Program measurement and science objectives.
**DECISION POINT FOR FUTURE PLANS**
- Should be an approach to a terrestrial space weather monitoring system.
- Decides how exploration of planetary space environments can most effectively be conducted. Good example is the proven strength of ENA imaging in the Saturnian system by Cassini.