Mission Name SDO: Solar Dynamics Observatory SDO Mission Patch LASP Instruments EVE: EUV Variability Experiment Principal Investigator: Unknown Destination Geosynchronous Orbit around Earth Launch Date October 2008 Launch Location Kennedy Space Center at Cape Canaveral, Florida Launch Vehicle Atlas V Booster Rocket Mission Duration 5 years Mission Description/ LASP involvement The primary goal of the SDO mission is to understand, driving towards a predictive capability, the solar variations that influence life on Earth and humanity’s technological systems by determining How the Sun's magnetic field is generated and structured. How this stored magnetic energy is converted and released into the heliosphere and geospace in the form of solar wind, energetic particles, and variations in the solar irradiance. LASP is building one of the three instruments (EVE) for SDO. (Read more about LASP involvement below). LASP Divisions Involved Engineering * Science * Mission Ops LASP Mission Web Page http://lasp.colorado.edu/eve Official Mission Web Page http://sdo.gsfc.nasa.gov

With the exception of the slow evolutionary changes in solar structure over the last 4.5 billion years, all solar variability is magnetic in origin. The solar cycle is a magnetic cycle in which the Sun's magnetic poles reverse with a periodicity of approximately 11 years and intense magnetic fields erupt through the surface in sunspots whose numbers wax and wane with the cycle. Solar flares and CMEs occur when magnetic fields are stressed beyond their limits. The very structure of the corona and the solar wind is determined by the structure of the magnetic field. The heating of the Sun's corona and the acceleration of the solar wind are thought to be due to interaction between small-scale magnetic elements.

SDO will help us to understand the mechanisms of solar variability by observing how the magnetic field is generated and structured and how this stored magnetic energy is released into the heliosphere and geospace.

The goal of SDO is to:

• Understand how magnetic fields appear, distribute, and disappear from their origin in the solar interior
• Understand the magnetic topologies that give rise to rapid high-energy release processes
• Study and gauge the dynamic processes which influence space weather phenomena
• Study the variations in irradiance and solar structure which occur on short timescales, as well as over the solar cycle

Engineering

LASP is building one of the three instruments to go on-board the SDO satellite:

• EVE: EUV Variability Experiment

Will measure the solar extreme ultraviolet (EUV) spectral irradiance to understand variations on the timescales which influence Earth’s climate and near-Earth space.

Science

LASP scientists will use the data from the EVE instrument to explore 4 primary science objectives:

1. Specify the solar EUV spectral irradiance and its variability on multiple time scales
2. Advance current understanding of how and why the solar EUV spectral irradiance varies
3. Improve the capability to predict the EUV spectral irradiance variability
4. Understand the response of the geospace environment to variations in the solar EUV spectral irradiance and the impact on human endeavors

Mission Ops

LASP's Mission Ops division will control the EVE instrument and its experiments.