NASA Logo, National Aeronautics and Space Administration

Sun-Earth Day Presents: Ancient Observatories, Timeless Knowledge

Technology Through Time: Issue #16, SDO

Our continued fascination with the sun will lead to even more discoveries about the role it plays in our lives.


The SDO spacecraft will be launched in April 2008 from Cape Canaveral and will be placed in a geosynchronous orbit around Earth where it will remain for at least five years. The orbit has an inclination of 28.5 degrees, and an altitude of 21,700 miles (35,000 Km)


The Observatory is one of the largest solar observing satellites. It has a mass (without propellant) of 1518 kilograms, and consumes 1260 watts of power and is about the size of a school bus, and it's instruments will produce about 150 megabits/sec of data which will be relayed to ground stations and scientists. From its position in geosynchronous orbit, SDO will trace a small figure-8 over a ground station at White Sands, a new facility that will be expressly built for the observatory.


The primary goal of the SDO mission is to understand the solar variations that influence life on Earth and humanity's technological systems. It will specifically investigate how magnetic fields are formed and dispersed on the solar surface, how they change their shapes and produce solar flare eruptions, and study the changes in solar brightness that can affect climate ion Earth. With this understanding would come the ability to predict the Sun's future activity, today, tomorrow and in the years to come. The instruments on-board SDO are what make this observatory unique and provide the data necessary to answer the questions raised from previous missions. SDO will capture 100 times more data than other solar observatories while producing very high resolution images of the Sun. The main instruments are:

Helioseismic and Magnetic Imager (HMI) - PI Institution: Stanford University
- Images the Sun's helioseismic, longitudinal, and vector magnetic fields to understand the Sun's interior and magnetic activity (

EUV Variability Experiment (EVE) - PI Institution: University of Colorado, Laboratory for Atmospheric and Space Physics
- Measures the solar extreme ultraviolet (EUV) spectral irradiance to understand variations on the timescales which influence Earth's climate and near-Earth space (

Atmospheric Imaging Assembly (AIA) - PI Institution: Lockheed Martin Solar & Astrophysics Laboratory
- Images the solar atmosphere in multiple wavelengths to link changes in the corona to changes in the surface & interior (



Image Gallery:


Photo Credit:

Barbara Lambert

Related Solar Dynamics Observatory (SDO) Links

NASA Logo -