Project Manager: Ken Schwer Project Scientist: Barbara Thompson Deputy Project Manager:Rob Lilly DPM Resources:Tom Miller Business Manager:Wanda Harrell Solar Dynamics Observatory (SDO)

Page 2SDO System Requirements Review/System Concept Review (SRR/SCR) – April 8-10, 2003 LIVING WITH A STAR (LWS) GOAL Develop the scientific understanding necessary to effectively address those aspects of the connected Sun-Earth system that directly affect life and society 2

Page 3SDO System Requirements Review/System Concept Review (SRR/SCR) – April 8-10, 2003 What SDO is designed to do Provide nearly continuous coverage of solar activity Provide coverage of the regimes (interior, photosphere, corona) in which the activity occurs Provide sufficient data on the types of phenomena which impact Earth, near-Earth space and humanity Observe over the relevant timescales (seconds to years) of solar variability In order to meet the needs of the Living With a Star program and determine the drivers and diagnostics of solar activity and variability which affect Earth and humanity, the Solar Dynamics Observatory must:

4 SDO OVERVIEW First Living With a Star (LWS) Mission, part of Sun-Earth Connection theme Will characterize the dynamic state of the Sun enhancing the understanding of solar processes and space weather. NASA GSFC will manage the mission, build the S/C in-house, manage and integrate the instruments, develop/manage the Ground System & Mission Operations, and perform Observatory environmental testing at GSFC SDO Investigations: –Helioseismic Magnetic Imager (HMI); PI: Phil Scherrer – Stanford; Images the Sun’s helioseismic and magnetic fields to understand the Sun’s interior and magnetic activity –Solar Heliospheric Activity Research & Prediction Program (SHARPP); Atmospheric Imaging Assembly (AIA) & Guide Telescope (GT) and White light coronagraph (KCOR); PI: Russ Howard – NRL; Images the corona to link changes to surface and interior changes –Extreme Ultraviolet Variability Experiment (EVE); PI: Tom Woods – LASP, Univ. of CO; measures the solar extreme ultraviolet (EUV) irradiance to understand variations August 2007 EELV launch from KSC into GEO-Transfer Orbit (GTO), circularize to GEO- Sync Orbit, inclined 28.5 degrees –Provide continuous high rate data (150 Mbps) stream to dedicated ground station –Spacecraft: robust, three-axis stabilized, solar-tracking with low jitter Design Drivers: Continuous high data rate/volume, Geosynchronous orbit (mass to orbit, radiation), 5 year mission life, Instrument pointing and stability

5 SDO Observatory Concept HMI EVE AIA Magritte AIA SPECTRE KCOR

Page 6SDO System Requirements Review/System Concept Review (SRR/SCR) – April 8-10, 2003 SDO investigations in brief The science of SDO will be performed by its three investigations: EUV Variability Experiment (EVE, PI: Tom Woods, University of Colorado): –Measure the EUV spectral irradiance from 0.1 to 105 nm at a cadence of 10 seconds. –EVE will specify the spectral irradiance with a sensitivity that allows us to gauge the energy input into the complex processes of the Earth's atmosphere and near-Earth space. Its temporal resolution will allow us, for the first time, to understand the flare-induced impacts on these processes. Helioseismic and Magnetic Field Investigation (HMI, PI: Phil Scherrer, Stanford University): –Measure the Doppler shifts due to oscillation velocities over the entire visible disk. –High-resolution measurements of the longitudinal and vector magnetic field over the whole visible disk of the Sun. –HMI will observe the interior processes governing the transition from solar minimum to solar maximum, will be able to probe the dynamics of the near-surface shear layer to observe local strong flux regions before they reach the photosphere, and will measure the highly variable magnetic field. Solar-Heliospheric Activity Research and Prediction Program (SHARPP, PI: Russell Howard, Naval Research Laboratory): –Seven telescopes with the spatial resolution of TRACE but a full-Sun field of view to provide chromospheric and coronal images at a 10-second cadence. –A high-cadence coronagraph to connect those measurements to the inner heliosphere. –SHARPP will capture the initiation and progression of dynamic processes, with the spatial resolution necessary to understand their connection to the magnetic field and the spectral coverage to infer the processes at multiple temperatures.

Page 7SDO System Requirements Review/System Concept Review (SRR/SCR) – April 8-10, 2003 The Science of SDO SDO is the first mission in the "Living With a Star" program. LWS is a program within NASA's Sun-Earth Connections theme. Living With a Star is a program which addresses the question "How and why does the Sun vary, how does the Earth respond, and what are the impacts on humanity?" Specifically, SDO will address the following LWS goals: –Understand solar variability and its effects on space and Earth environments. –Obtain information for mitigating undesirable effects of solar variability on human technology. –Understand how solar variability can affect life on Earth: To enable better understanding of global climate change caused by both natural (solar variability, volcano eruptions) and human drivers. To better predict how stellar variability affects life in other stellar systems. SDO builds on the tremendous success of recent missions such as SOHO, TRACE, TIMED and SORCE (among others). We ensure the scientific success of SDO by learning from our previous success, taking into account the unique assets and challenges of SDO. The international partnership of LWS is called International Living With a Star (ILWS).

Page 8SDO System Requirements Review/System Concept Review (SRR/SCR) – April 8-10, 2003 The Science of SDO The goal of SDO is to answer the following questions: 1.What mechanisms drive the quasi-periodic 11-year cycle of solar activity? 2.How is active region magnetic flux synthesized, concentrated, and dispersed across the solar surface? 3.How does magnetic reconnection on small scales reorganize the large-scale field topology and current systems? How significant is it in heating the corona and accelerating the solar wind? 4.Where do the observed variations in the Sun’s EUV spectral irradiance arise, and how do they relate to the magnetic activity cycles? 5.What magnetic field configurations lead to the CMEs, filament eruptions, and flares that produce energetic particles and radiation? 6.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? 7.When will activity occur, and is it possible to make accurate and reliable forecasts of space weather and climate? From the SDO Science Definition Team Report, July 2001

Page 9SDO System Requirements Review/System Concept Review (SRR/SCR) – April 8-10, 2003 Science Questions SDT -> AO AO Measurement Objectives Level 1 Science Measurement Requirements E/PO Program SDO Investigations: Develop Instrumentation to meet Level 1 Measurement Requirements Propose Science Investigations to answer Science Questions Communicate results through scientific journals and E/PO program Research and Data Analysis Data Products Research and Data Analysis

Page 10SDO System Requirements Review/System Concept Review (SRR/SCR) – April 8-10, 2003 Investigation Science Objectives The PI Teams, in response to the AO, have devised investigations designed to answer all seven of these questions. Each investigation has defined a set of Investigation Science Objectives: EVE E-1. Specify the solar EUV spectral irradiance and its variability on multiple time scales E-2. Advance current understanding of how and why the solar EUV spectral irradiance varies. E-3. Improve the capability to predict the EUV spectral irradiance variability. E-4. Understand the response of the geospace environment to variations in the solar EUV spectral irradiance and the impact on human endeavors. HMI H-1. Convection Zone dynamics and solar dynamo H-2. Origin and Evolution of sunspots, active regions and complexes of activity H-3. Sources and drivers of solar activity and disturbances H-4. Links between the internal processes and dynamics of the corona and heliosphere H-5.Precursors of solar disturbances for space weather forecasts SHARPP S-1. Link solar magnetic features to irradiance variability at earth S-2. Link observed/derived plasma characteristics to the associated magnetic structures throughout the photosphere, chromosphere, transition region, and corona, as they evolve over the solar cycle S-3. Determine the nature of the coronal heating mechanism(s) S-4. Understand the origin of flares and their relation to CME’s S-5. Detect and measure reconnection signatures (e.g., Jets) characteristic of competing CME initiation models S-6. Understand the origin and nature of global waves and dimmings that accompany many fast CME’s S-7a. Determine the effects of ambient magnetic field topology and complexity will have on the initiation and propagation of CMEs S-7b. Determine the factors associated with geoeffectiveness of CMEs over the solar cycle S-8. Understand the heating and initiation of the fast wind in coronal holes S-9. Understand active region expansion, streamer formation, and the nature of the slow wind

Page 11SDO System Requirements Review/System Concept Review (SRR/SCR) – April 8-10, 2003 Linkage from Science Goals to Objectives By satisfying the Investigation Science Objectives, the Science Goals of SDO are addressed, as shown in the following table ("X" denotes an Objective that directly addresses a Science Goal, while "S" indicates an Objective which supports the goal.)

Page 12SDO System Requirements Review/System Concept Review (SRR/SCR) – April 8-10, 2003 SDO Measurement Objectives 1.Provide data for near-surface diagnostics of the dynamics of the solar interior that are sufficient for both global and local helioseismology. (Dopplergrams) 2.Provide information about the global solar magnetic field, the active region evolution, small-scale features, and sources of irradiance variations. (Longitudinal and Vector Magnetic Field Images, Atmospheric Images, Spectral Irradiance Measurements) 3.Characterize the rapid evolution of plasma in the chromosphere and lower corona with a field of view and spectral coverage sufficient to facilitate linkage with the coronagraph images and to help interpret the EUV spectral irradiance measurements. (Atmospheric Images, Coronagraphic Images, Spectral Irradiance Measurements) 4.Characterize the solar extreme ultraviolet (EUV) irradiance on timescales ranging from seconds to years to understand the solar variation caused by solar magnetic field evolution, and to study the solar induced variations of the Earth's ionosphere and thermosphere. (Longitudinal and Vector Magnetic Field Images, Atmospheric Images, Spectral Irradiance Measurements) HMI: Doppergrams, Londitudinal and Vector Magnetic Field Images EVE: Spectral Irradiance Measurements SHARPP: Atmospheric and Coronagraphic Images

Page 13SDO System Requirements Review/System Concept Review (SRR/SCR) – April 8-10, 2003 To meet the Science Measurement Objectives for Full Mission Success, the following Measurement Requirements must be performed by SDO: Spectral Irradiance Measurements in the.1 to 105 nm range and continuum emission, at a cadence of no slower than 20 seconds, for input to ionospheric and upper atmospheric models important for the LWS Program. At least 18 emission lines at a spectral resolution of 0.1 nm. The absolute accuracy of these emissions should be 25% or better for the duration of the prime mission. These 18 emission lines shall be chosen to adequately characterize the solar EUV spectrum variations for LWS/Geospace applications. EVE Dopplergrams. Full-disk, 1.5-arcsec resolution photospheric velocity measurements every 50 seconds with an accuracy of TBD m/sec. More than 95% of the dopplergrams must be recovered, with 99.99% data completeness. HMI Longitudinal Magnetograms. Full-disk, 1.5-arcsec resolution longitudinal magnetic field images every 50 seconds. Measurement of these features requires a noise level of 17 Gauss (G) with a dynamic range of +-3 kG. HMI Vector photospheric magnetic field observations over the whole disk with 1.5-arcsec resolution every 10 minutes with a polarization accuracy of.3%. HMI Atmospheric Images. Full-disk 1.32-arcsec resolution images of the solar atmosphere in seven wavelengths spanning the temperature range 20,000 to 3 million Kelvin (K) with a cadence of one set every 10 seconds. Intercalibration of intensity between the images to ~20%. Field of view in appropriate temperature regimes should extend to 1.35 solar radii to facilitate linkage with white-light coronagraph (see below) observations. SHARPP White light coronagraphic polarization and brightness images with a time cadence of 60 seconds per sequence, with a pixel size of 15 arcseconds in the range 2 to 15 solar radii and an accuracy of 10%. SHARPP

Page 14SDO System Requirements Review/System Concept Review (SRR/SCR) – April 8-10, 2003 Defining the Minimum Mission The table indicates that most of the Science Questions can be addressed in the event of a single instrument failure.

Page 15SDO System Requirements Review/System Concept Review (SRR/SCR) – April 8-10, 2003 A FULL MISSION SUCCESS CRITERIA The following measurements shall be obtained over the prime mission life of five years to obtain full mission success: All three investigations operating 80% of the time over the course of 5 years. Instrument performance commensurate with the Science Instrument Full Performance Requirements. A MINIMUM MISSION SUCCESS CRITERIA Tables A-1 and A-2 indicate that most of the Science Goals of SDO can be addressed in the event of an instrument failure. Therefore, the minimum success criteria for the SDO are as follows: Two out of the three investigations operating 40% over the course of 5 years. Instrument performance commensurate with the Science Instrument Minimum Performance Requirements.

16 SDO PROJECT STATUS Project Science Team System Engineering S/C Subsystems Launch Services Procurement Cost Schedule Manpower Ground System Ground Network Data Distribution Mission Ops. & MOC SOCs Instrument HMI SHARPP EVE Summary Assessment Technical Cost Schedule Management Spacecraft Instrument Ground System Launch Vehicle JAN FEB MAR Y Y Y LEGEND Y R GOOD SHAPEMINOR PROBLEM MAJOR PROBLEM Y Y Y Y

17 SIGNIFICANT EVENTS Successfully completed EVE, HMI, & SHARPP Instrument Systems Requirements Retreats. Completed all necessary draft documentation (37 items) & 2 weeks of dry-runs in preparation for the SRR/SCR (1 st external review). Successfully conducted SRR/SCR. –2.5 days, 940 pages, 46 items of documentation available (hard copy & electronic) for review. –Also conducted (1/2 day) Project Management splinter (WBS, cost/schedule estimates, make/buy, dependencies/agreements, project controls, information mgmt., risk mgmt., E&PO). HQ’s considering adding another small instrument(s) to SDO mission –DORADE (Davos Observatory RADiometer Experiment), which is a pair of radiometers for total solar irradiance measurement. HQ trying to work a no cost deal with ESA/Swiss. –HQ’s also trying to sell excess EELV capability (approx. 700 kg) or partner with another agency to offset costs. Working POP 03-1 exercises. –Do not descope science or the mission at this time. –Determine phasing for 4/08 launch in order to support a possible L.V. partnership with DOD. –Stay in-guide for FY04 & FY05 and determine launch date & new total.

18 SDO CRITICAL MILESTONE CHART Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Critical Milestone Explanation of Missed Milestones: Internal System Requirements Retreat Instrument System Requirements Reviews (SRR) Instrument Facilities External SRR/Systems Concept Review (no earlier than) 3/20 2/ /8 2 Initial Confirmation Review (no earlier than) Mission Preliminary Design Review (no earlier than) /12 5/30 1 5Completed grassroots schedule estimates. Additional time to PDR required, still 6 months contingency to 8/07 launch. 1

19 SDO Project Summary Schedule