Space Weather Workshop, April 2008 Solar Dynamics Observatory W. Dean Pesnell NASA, Goddard Space Flight Center SDO Project Scientist

Space Weather Workshop, April 2008 There lands the Fiend, a spot like which perhaps, Astronomer in the Sun's lucent Orbe through his glaz'd Optic Tube yet never saw. John Milton, Paradise Lost, 1674, Book 3, Line 590.

Space Weather Workshop, April 2008 Solar Dynamics Observatory The Solar Dynamics Observatory (SDO) is the first Living With a Star mission. It will use telescopes to study the Sun’s magnetic field, the interior of the Sun, and changes in solar activity. Some of the telescopes will take pictures of the Sun, others will view the Sun as if it were a star. 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.

Progress in Past Year Instruments delivered and installed Observatory assembled Environmental testing has begun –EMI/EMC complete –Vibe/acoustics this week and next –Thermal vacuum starts in June Ground system running at full mission data rate Launch December 2008 Sun has not started the climb to Solar Cycle 24 No major issues or problems! Space Weather Workshop, April 2008

SDO: NASA/LWS Cornerstone Solar Mission NASA and three Instrument Teams are building SDO –NASA/ Goddard Space Flight Center: build spacecraft, integrate the instruments, provide launch and mission operations –Lockheed Martin & Stanford University: AIA & HMI –LASP/University of Colorado & USC: EVE Launch is planned for December 2008 on an Atlas V EELV from SLC 41 at Cape Canaveral SDO will be placed into an inclined geosynchronous orbit ~36,000 km (21,000 mi) over New Mexico for a 5-year mission Data downlink rate is 150 Mbps, 24 hours/day, 7 days/week (watching 380 movies each day) Atlas V carries Rainbow 1 into orbit, July 2003.

Space Weather Workshop, April 2008 Why So Much Data? A goal of LWS is to predict Space Weather (SWx). Why is there so much data from SDO and how can it be used to make those forecasts, today, next year, and the next solar cycle? The data returned by SDO was designed to have: Simultaneity: Full-disk images at many wavelengths every 1.25 seconds to resolve the time dependence of the flaring regions at different temperatures Coincidence: Full-disk EUV images to see the entire face of the Sun in each image, important for complete coverage and non-local effects; full-disk magnetograms to track the magnetic field Resolution: 1.7 ” images at a 10 second cadence Long-term: Cover an appreciable part of the solar cycle

Why So Much Data? Space Weather Workshop, April 2008 A betting matter in the 19 th century was whether a galloping horse ever had all four hooves off the ground at the same time. Eadweard J. Muybridge was a pioneering photographer who investigated this question. His patron was the founder of Stanford University. Le derby d'Epsom, by Théodore Géricault, 1821 This picture shows the view that the hooves were off the ground in a leaping motion.

Why So Much Data? Space Weather Workshop, April 2008 Muybridge knew that the stride of a galloping horse was too long for a single camera and used 16 cameras to emulate a moving frame of reference. He also knew that multiple cameras were necessary because the film could not be advanced quickly enough. The shutter speed was fast enough and the shutters were tripped by electrical signals triggered by the horse’s hooves. Le derby d'Epsom, by Théodore Géricault, 1821 Muybridge needed data that showed all of the hooves at the same time (coincidence) but simultaneity in colors was not important. It was essential to resolve the motion.

Why So Much Data? Space Weather Workshop, April 2008 The animated version of Muybridge’s images can be found at

Space Weather Workshop, April 2008 Trace image of a filament eruption from AR on March 3, Even this late in the solar cycle the fields are complex. Still need the full- disk temperature maps to understand these motions. Unlike a horse’s gait each active region is different! What will we learn from the magnetic field measurements? Movie available at:

Space Weather Workshop, April 2008 The SDO Spacecraft The total mass of the spacecraft at launch is 3200 kg (payload 270 kg; fuel 1400 kg). Its overall length along the sun- pointing axis is 4.5 m, and each side is 2.22 m. The span of the extended solar panels is 6.25 m. Total available power is 1450 W from 6.5 m 2 of solar arrays (efficiency of 16%). The high-gain antennas rotate once each orbit to follow the Earth. AIA (1 of 4 telescopes) EVE (looking at CCD radiator and front) HMI (looking down from top) High-gain antennas Solar arrays

Space Weather Workshop, April 2008 SDO Operations Mission Operations Center for SDO is at NASA's Goddard Space Flight Center in Greenbelt, MD. –Maintain its inclined geosynchronous orbit –Keep SDO pointing at the Sun –Keep the data flowing. Communications with the spacecraft are via two radio dishes at NASA's site in the White Sands Missile Range in New Mexico. Science teams plan operations of the instruments with MOC and analyze the data. Operations Philosophy –Few modes: turn it on and let the data flow! –Images are sent to the ground for processing –Data is made available soon after downlink; people can use the data in near-real-time –Campaigns and collaborations are coordinated when convenient, but the data is always available 18 m antenna assembly MOC in Building 14

Space Weather Workshop, April 2008 SDO Operations SDO will produce an enormous amount of data –1.5 Terabytes each day –Almost 0.75 petabytes each year DDS acts as observatory tape recorder Data is forwarded to SOCs, who archive and serve the data Two copies exist at all times after data is on the ground Data flow is similar to watching 380 movies every day –Some channels are actually measured more frequently –500,000 iTunes downloads each day Data Distribution System being test in Building 14 (60 TB raid storage)

Space Weather Workshop, April 2008 Space Weather Data InstrumentDescription of Space Weather Data Product EVE1-minute, 1-nm spectral irradiance for MEGS-A 1-minute, 1-nm spectral irradiance for MEGS-B 10-sec averaged ESP and MEGS-P bandpasses 10-sec flare location from ESP quad diode and SAM 10-sec emission lines (TBD), 15 min latency AIAQuick-look intensity images, 1024 x 1024 pixels, 8 wavebands, 10 sec cadence, 15 min latency HMIQuick-look longitudinal magnetograms and continuum images, 50 sec cadence, 15 min latency A summary of SDO SWx data. Data will be placed at a site accessible via the Internet. Your cadence may be different.

HMI Space Weather Plans Near realtime (< 15 min delay) SWx data – 4k x 4k magnetogram – LOS with 50 sec. cadence, vector every 10 min. – Magnetic indices are being developed and need to be assessed by the SWx community – Continuum images Helioseismic data products – Far-side images Models of the convection zone and dynamo – Active region emergence and evolution – Magnetic field creation and emergence – Enables the prediction of long-term solar activity Available from the JSOC as a pull product

AIA Space Weather Plans Near realtime (< 15 min delay) SWx data – Irradiance-c alibrated images in 9 UV/EUV/X-ray wavelengths – EVE provides irradiance calibration of images – Quicklook data (1kx1k images, movies at each wavelength covering past hour & day.) Image analysis to improve near-term predictions of flares and other solar activity – Temperature proxies to provide better flare predictions? – Locations of coronal holes, the sources of high-speed streams Models of the coronal magnetic field, predictions of the solar wind Available from the AIA web site or the JSOC as a pull product

EVE Space Weather Plans Provide near realtime (< 15 min delay) SWx data: –High resolution spectra (as counts or “crudely” calibrated) (MEGS) 10 second cadence –Broadband solar irradiances (ESP and MEGS-P) More rapid (4 Hz) cadence –First-ever near-realtime XUV and EUV flare monitor SWx data to be used by: –Ionospheric disturbance nowcasting (XUV/EUV flare response) –Operational GAIM (Global Assimilative Ionospheric Model) –Operational SOLAR2000 (solar irradiance model), which is in-turn used as a driver for operational atmospheric, ionospheric, and neutral thermospheric wind models SWx data will be available as a pull product from EVE web site –May also be served through NOAA-SEC

Space Weather Workshop, April 2008 SDO Construction View of SDO with HMI and EVE. SDO almost complete in Building 7 at GSFC. View of AIA side.

SDO Construction Space Weather Workshop, April 2008

SDO Construction Space Weather Workshop, April 2008

Summary 1.The Sun’s magnetic field is the source of almost all SWx. As the Sun waxes and wanes with the solar cycle we must monitor its ability to affect spacecraft and society. 2.Our modern world requires knowledge of The Sun Today. 3.Global and local data are needed to provide this knowledge. Measure global data, Observe the Database for local data. 4.SDO will measure the Sun’s light output and magnetic field, making Ultrasounds of the Sun and allowing us to model the Plasma Environment of the Lower Corona. 5.SDO will allow us to predict when the Sun will affect spacecraft and society.

Space Weather Workshop, April 2008 Contact Information W. Dean Pesnell: soon to be