The Solar Dynamics Observatory, or "SDO" for short, will gather data on the sun. From a geosynchronous orbit over a specially-constructed communications center in New Mexico, SDO will capture detailed images of the surface of the sun and take accurate measurements of changes in the sun's magnetic field and the solar wind.
Ultimately, the data from SDO should reveal some of the mysterious inner workings of the sun. For example, it's long been known that the sun undergoes a regular eleven-year cycle of magnetic intensity, resulting in a spate of solar flares every eleven years that can damage satellites. However, the cause of this cycle is unclear. SDO should also provide us with better tools to predict solar disturbances that occur seemingly at random, and can harm astronauts and sensitive electronics in Earth orbit. The stated scientific goals of the mission are to answer, or at least gather information on, these seven questions:
- What mechanisms drive the quasi-periodic 11-year cycle of solar activity?
- How is active region magnetic flux synthesized, concentrated, and dispersed across the solar surface?
- How does magnetic reconnection on small scales reorganize the large-scale field topology and current systems and how significant is it in heating the corona and accelerating the solar wind?
- Where do the observed variations in the Sun's EUV spectral irradiance arise, and how do they relate to the magnetic activity cycles?
- What magnetic field configurations lead to the coronal mass ejections, filament eruptions, and flares that produce energetic particles and radiation?
- Can the structure and dynamics of the solar wind near Earth be determined from the magnetic field configuration and atmospheric structure near the solar surface?
- When will activity occur, and is it possible to make accurate and reliable forecasts of space weather and climate?
SDO is also the first mission in NASA's Living With a Star program, a series of projects designed to investigate space weather and its effects on Earth. Future program missions include the Geospace missions, which will measure the radiation belts around Earth that result from the Earth's magnetic field interacting with charged solar particles, and a solar probe that will fly into the sun's corona!
You can learn much more about SDO at the mission web site, or by reading the official mission guide.