What is SDO and what is its purpose and mission?
Q and A with SDO Program Executive Dana Brewer
SDO is the Solar Dynamics Observatory. Its purpose is to study the scientific processes that produce change inside, at the surface, and in the atmosphere of the sun. Changes in the sun, or solar variability, produce changes in the levels of radiation and energy in the heliosphere (or space) within our solar system. The changes are called space weather, and they affect communications and other satellite signals, electrical power lines, radiation doses to polar aircraft/crew, and spacecraft components and occupants both near and away from Earth.
What's different or unique about SDO?
SDO will take measurements of the entire solar disc for 22 72-day time periods over SDO’s 5-year prime mission life. This equates to 4 years of data, and the prime mission lifetime is approximately half of the time period for an 11-year cyclical solar cycle. SDO’s instruments will look at the inside, surface, and corona of the sun at the same time, so the causes of solar variations can be identified together with the outcomes from the causes. For example, if there are a lot of intertwined magnetic field lines inside the sun, a specific combination of the lines and their strengths may be able to be attributed to a solar flare. If we can figure out many of these cause and effect relationships, we will have a start on developing a predictive space weather capability.
What is space weather?
Space weather is the state of the heliosphere that changes due to solar variability. The heliosphere is the region of the sun’s influence, our solar system. Space weather effects are the deleterious consequences of space weather, and they include things that can be changed by changing the ionizing radiation dose and/or the electrical and magnetic fields from the sun.
How will SDO improve our knowledge and understanding of space weather?
SDO will allow us to study causes and effects on the sun. We are viewing the entire disk of the sun all the time, and our data from viewing result in simultaneous data from the inside, surface, and atmosphere of the sun. This allows the scientists to develop cause and effect relationships between activities in the different layers of the sun. Only when this is done will we truly have a foundation to develop a predictive capability for space weather.
How will the SDO mission benefit the average person?
The SDO mission will lead to a predictive space weather capability. This capability will allow us to disconnect the connections in the electrical power grid when solar activity has the potential to damage power transmission hardware; this will allow the damage to be localized instead of resulting in an extended power outage across the eastern or western seaboard of the U.S. An extended power outage would ripple across the U.S. infrastructure, leading to problems with water distribution and loss of perishable foods, medications, heating/air conditioning, sewage disposal, phone service, etc. The space weather predictive capability will also allow accurate adjustments of satellites signals to ensure the uninterrupted retention of communications with ships, medical pagers, and telecommunications ground stations.
What is the life cycle of the SDO mission? Can it last longer?
The prime mission life of the SDO is 5 years, and, under a worst case condition, there is fuel available to extend the mission by another 5 years. There may be additional fuel if the Observatory’s fuel is not used to reach geosynchronous transfer orbit immediately after launch. The SDO lifetime also depends upon the extent of degradation of the Observatory’s microelectronics due to the harsh ionizing radiation environment in geosynchronous Earth orbit.
What science instruments will SDO carry?
SDO will carry three instruments. The Helioseismic and Magnetic Imager (HMI) will map the sun’s magnetic fields and peer beneath the sun’s surface to decipher the physics of the core of the sun which is the solar dynamo. The Atmospheric Imaging Assembly (AIA) is a set of 4 telescopes designed to photograph the sun’s surface and atmosphere in 8 wavelengths simultaneously. The Extreme Ultraviolet Variability Experiment (EVE) will measure fluctuations in the sun’s ultraviolet energy output, and this output has a direct effect of heating, changing the density, and breaking apart atoms and molecules in the Earth’s upper atmosphere.
Where will the data be stored and who will look at the data produced by SDO?
The SDO data will be transmitted from the Observatory to a ground station in Las Cruces, New Mexico. The ground station will immediately transmit the data to the two Science Operations Centers at the University of Colorado and Stanford University; it will also store the data for up to 30 days for re-transmission to the Science Operations Centers in the event that the first transmission is not successful. Each SDO instrument is part of a science investigation team that has many science co-investigators. The three science teams are responsible for initial processing of the raw science data and making the initial detailed products available to the public in as short a time as possible after SDO is commissioned. In addition, short-term quick look products may be available several times per hour. So, in the future, you may be able to routinely get a status of the sun on your cell phone or over the Internet.
What made you choose science/engineering as a career?
I enjoyed chemistry and math when I was in high school. I also thought of how great it would be to participate in the space program when I saw the Mercury and Gemini astronauts going into space. I accepted the challenge of succeeding in science when a chemistry professor told me that women should not get science degrees, because it’s a man’s field. (This was many years ago, before the onset of “women’s liberation.”) I recall that there were about 6 females in the first of three sophomore physics courses out of 600 students. By the time we got to the third course, the 6 females were still in the course, but the class size had decreased to 200. When I graduated from undergraduate school, jobs were scarce (another economic downturn), and I accepted a graduate teaching assistantship in chemistry. After obtaining my Ph.D., I did theoretical chemistry research for 10 years until an opportunity became available for me to transition from science to engineering. The rest is history. After all, where else can I live my dream? Society’s acceptance of female engineers has caught up with my activities.
What advice would you give young women interested in pursuing careers in science or engineering?
Pursue your dreams, but understand that science and engineering are more time-consuming courses of study than other majors. Accept the challenge, because you will do well and enjoy your career. Live your dream.
About Dana Brewer
- B.S. in general Science from Penn State, Ph.D. in Quantum Chemistry from Virginia Tech.
- Ten years as contractor at NASA Langley doing earth science atmospheric modeling.
- 6 years as space environments requirements manager at Space Station Level II Program Office in Reston.
- 5 years as Program Manager in spacecraft technology development (including space environments).
- 4 years as New Millennium Program Manager (including flight validation of ion propulsion on Deep Space-1 mission.
- 14 years as Program Executive in Heliophysics Division in Science Mission Directorate (includes formulation of Hinode, STEREO, Space Environment Testbeds and the Living With a Star and Solar Terrestrial Probes Programs; pre-formulation of Radiation Belt Storm Probes, Solar Orbiter, Solar Probe Plus; implementation of SDO, LWS program, and Space Environment Testbeds.).