W. Dean Pesnell
NASA, Goddard Space Flight Center
SDO Project Scientist
for the SDO Team
SORCE Team Meeting, May 2010
• Welcome to Solar Cycle 24
• Introduction to SDO
• The SDO instruments
• The new data
Why is an understanding of solar activity important?
Galaxy 15 no longer responds to ground commands after a
solar event on April 8. Thousands of Luxembourgeois are
threatened with loss of cable TV.
Brings back memories of the Galaxy IV failure in 1998 that
took out 80% of the pagers in North America. When Sheldon of The Big Bang Theory was delayed
he said solar flares disturbed the GPS constellation.
SORCE Team Meeting, May 2010
As we move into the rise to the
maximum of Solar Cycle 24 the
equatorial coronal holes are
fading and active regions and
coronal loops have reappeared.
At this time in the solar cycle
our Space Weather is dominated
by the emerging active regions
and the brightening
chromospheric network.
http://sdowww.lmsal.com/
suntoday
http://sdo.gsfc.nasa.gov
AIA Fe XII 193
(roughly 1.5 million K)
SORCE Team Meeting, May 2010
SORCE Team Meeting, May 2010
•  How and why does the Sun vary?
•  How does the Earth respond?
•  What is the effect on life and
technology?
Coronal holes from Skylab
Polar routes can’t
be flown during
significant solar
activity
Model exospheric temperature
changes with solar activity
SORCE Team Meeting, May 2010
Deliberate and accidental satellite breakups have increased the amount
of tracked orbital debris by 20-40%! Without an dramatic increase in
solar activity we may have to live with this debris for a century.
SORCE Team Meeting, May 2010
X-rays,
EUV, UV, &
Visible
Solar Wind &
Magnetic Field
SORCE Team Meeting, May 2010
On January 21, 2010, SDO posed inside the Astrotech clean room.
SORCE Team Meeting, May 2010
SORCE Team Meeting, May 2010
The total mass of the spacecraft
at launch was 3000 kg (payload
300 kg; propellant 1400 kg).
Its overall length along the sunpointing axis is 4.7 m, and each
side is 2.2 m.
The span of the extended solar
panels is 6.25 m.
Total available power is 1500 W
from 6.6 m2 of solar arrays
(efficiency of 16%).
Launched on February 11, 2010 aboard an
Atlas V EELV with Centaur second stage
SDO is now in an inclined geosynchronous
orbit ~36,000 km (21,000 mi) at the longitude
of New Mexico for a 5-year mission
SORCE
SIP Workshop,
Team Meeting,
October
May
2008
2010
The high-gain antennas rotate
once each orbit to follow the
Earth.
•  EVE is the Extreme ultraviolet Variability
Experiment
•  Built by the Laboratory for Atmospheric and
Space Physics at the University of Colorado
in Boulder, CO
•  EVE uses gratings to disperse the light
•  Data will include
–  Spectral irradiance of the Sun
•  Wavelength coverage 0.1-105 nm and
Lyman α
•  Full spectrum every 10 s
–  Space weather indices from photodiodes
–  Information needed to drive models of
the ionosphere
–  Cause of this radiation
–  Effects on planetary atmospheres
SORCE Team Meeting, May 2010
•  The solar spectral irradiance causes much of what we call space weather
•  This irradiance has been reported by SEE on TIMED as daily and orbital values
•  Identifying the sources of this irradiance is a major goal of SDO
•  EVE will provide a near-realtime data stream to SWPC from the ESP
radiometers
SORCE Team Meeting, May 2010
SORCE Team Meeting, May 2010
•  AIA is the Atmospheric Imaging Assembly
•  Built at Lockheed Martin Solar and Astrophysics
Laboratory in Palo Alto, CA
•  Four telescopes with cascaded multi-layer
interference filters to select the required
wavelength
–  Filters are at 94, 131, 171, 193, 211, 304, 335,
1600, 1700, and 4500 Å
–  4096 x 4096 CCD
•  Data will include
–  Images of the Sun in 10 wavelengths
•  Coronal lines
•  Chromospheric lines
•  An image every 1.25 seconds
–  Guide telescope for pointing SDO
SORCE Team Meeting, May 2010
Fe XV 284
Fe IX/X 171
SORCE Team Meeting, May 2010
He II 304
• Images of the Sun in 10
bandpasses covering a
temperature range of 50,000 K
to 3 million K
• Images of the corona and
chromosphere
• Eight images every 10 seconds
• 70,000 images a day!
• Each must be scaled in size,
rotated, registered to solar
center, and calibrated
• Analysis difficulties change with
the solar cycle; distinguishing
features at min., loops and flares
at max.
SORCE Team Meeting, May 2010
SORCE Team Meeting, May 2010
SORCE Team Meeting, May 2010
SORCE Team Meeting, May 2010
•  Built at Stanford University and Lockheed
Martin in Palo Alto, CA
•  Uses bi-refringent materials as spectral filter
•  Two 4096 x 4096 CCDs
•  72,000 Images each day become
–  1800 Dopplergrams each day
•  Oscillations
•  Local Analysis
•  Internal velocities
–  1800 Longitudinal magnetograms daily
–  150 Vector magnetograms daily
HMI and AIA will use six 4096 x
4096 CCDs built by e2v in
England.
SORCE Team Meeting, May 2010
SORCE Team Meeting, May 2010
SORCE Team Meeting, May 2010
SORCE Team Meeting, May 2010
The Solar Dynamics Observatory (SDO) is
the first Living With a Star mission. It will
study the Sun’s magnetic field, the interior
of the Sun, and changes in solar activity. It
is designed to be our solar observatory for
Solar Cycle 24. • 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.
SORCE Team Meeting, May 2010