SOHO Science Operations Now and Then

1. SOHO Science OperationsNow and Then Bernhard Fleck SOHO Project Scientist bfleck@esa.nascom.nasa.gov

2. Outline • Mission overview • Science operations setup • Experimenters’ Operations Facility (EOF) • Planning process • SOHO Joint Observing Plans (JOPs) • SOHO Science Operations Coordinators (SOCs) • Data processing, archiving and data distribution • SOHO science operations now • Summary / lessons learned

3. SOHO – quick facts • Joint ESA/NASA mission • Built in Europe, launched by NASA (2 Dec 1995) • Operated from NASA/GSFC • Orbits around L1 • Nominal mission: 2 years • 12 instruments aboard

4. SOHO’s science objectives A) Solar Interior What are its structure and dynamics? B) Solar Corona Why does it exist and how is it heated? C) Solar Wind Where is it accelerated and how?

5. Key results • First images of the interior of a star • Coronal heating • Solar wind acceleration • Monitoring total solar irradiance (‘solar constant’) and EUV flux • Revolutionized our ability to forecast ‘space weather’ • Discovered over 2000 comets

6. SOHO Experimenters’ Operations Facility • Located at NASA/GSFC, next to SOHO MOC • Co-location of experiment teams and SOHO FOT • Proved to be very beneficial (a) operational, b) public affairs / tour groups) • Heritage from earlier solar physics missions: OSO, Skylab, SMM • Focal point for mission science planning and instrument operations • Became “Mecca of Solar Physics” • Influenced a whole generation of solar physicists • Reception of real-time and playback telemetry • Data processing to determine instrument commands • Near real-time commanding directly from instrumenters’ workstations • Resembles more operations of a ground-based observatory than operations of a conventional space-based observatory • Allows for quick reaction to targets of opportunity (re-pointing)

7. SOHO Experimenters’ Operations Facility CDS SUMER MDI Meeting Room UVCS EIT LASCO SOCs PS

8. SOHO Experimenters’ Operations Facility

9. Science planning • SOHO from the beginning conceived as a package of complementary instruments  coordination critically important for mission success • “Maximizing immediate and future scientific output of all SOHO observations” • Unique input for numerical modeling of solar phenomena • Planned and ad hoc campaigns (co-observations) • Joint Observing Programs (JOPs) • Coherent observing plans to maximize the scientific return of the individual instruments by coordinating their plans for the study of specific solar phenomena • Many JOPs involve collaborations with ground-based observatories or other space missions • 227 science JOPs and 14 IntercalibrationJOPs • http://soho.nascom.nasa.gov/soc/JOPs/ • SOHO campaign database: 1307 records • Word Wide Web key tool for SOHO science operations from the very beginning • Software planning and scheduling tool developed for SOHO (in IDL)

10. Science planning tool

11. Science planning process • Nested scheme: monthly, weekly, daily meetings, with strategic input from quarterly SWT meetings • Quarterly SWT meetings: • Overall observing priorities • Major campaigns like “Whole Sun Month” • Policies regarding reaction to Major Flare Watches • Resolution of conflicts and disputes • Guest Investigator proposals • Monthly meetings: • General observing plan for coming month by Science Operations Team (SOT) • Scheduling of campaigns and JOPs • Weekly and daily meetings: • Refinements of monthly plan • Coordination with ground-based observatories • Final pointing up-dates

12. SOHO Science Operations Coordinators • 1 ESA, 2 NASA (+ several student SOCs for off-hours and weekends) • Interface between instrument teams and FOT • Focal point-of-contact for joint observing campaigns with other space missions and ground-based observatories • Coordination of special operations • S/C roll • S/C off-pointing • calibration rockets • Maintain long-term plan, campaign databases, etc. • First priority: instrument health and safety

13. Operations overview Instruments with constant operational presence at the EOF CDS Flight Operations Team UVCS SOC LASCO EIT MDI

14. Operations overview CDS Flight Operations Team UVCS SOC LASCO EIT MDI TRACE TRACE is sometimes dubbed the 13th SOHO instrument, with constant EOF presence

15. Operations overview SWAN team in Europe sends delayed command files to EOF. Present at EOF for “special operations” (engineering etc). SWAN CDS Flight Operations Team UVCS SOC LASCO EIT MDI TRACE

16. Operations overview SUMER operates only during special campaigns with EOF presence SUMER SWAN CDS Flight Operations Team UVCS SOC LASCO EIT MDI TRACE

17. Operations overview Particle Exp. GOLF GOLF, VIRGO, CELIAS, ERNE, and COSTEP send delayed command files daily or weekly (if any at all). VIRGO SUMER SWAN CDS Flight Operations Team UVCS SOC LASCO EIT MDI TRACE

18. Operations overview Particle Exp. GOLF VIRGO SUMER MEDOC SWAN CDS Flight Operations Team UVCS SOC LASCO EIT Multi-Experiment Data Operations Centre for SOHO (MEDOC) “Sister EOF” at Institutd'AstrophysiqueSpatiale (IAS) in Orsay, France. Capability to send near-real-time commands, reception of real-time telemetry. Hosts “MEDOC Campaigns” with most daily science planning, and some commanding, performed at MEDOC. MDI TRACE

19. Operations overview Particle Exp. GOLF VIRGO SUMER MEDOC SWAN CDS Flight Operations Team UVCS SOC LASCO EIT Joint observations with other spacecraft…… MDI TRACE ULYSSES STEREO Yohkoh Hinode RHESSI

20. Operations overview Particle Exp. GOLF VIRGO SUMER MEDOC SWAN CDS Flight Operations Team UVCS SOC LASCO EIT MDI Big Bear Kitt Peak La Palma TRACE Tenerife ULYSSES STEREO Yohkoh Hinode RHESSI …and ground based observatories

21. Data processing • Telemetry (both real-time and recorder dumps) flow in real-time from DSN to SOHO EOF at GSFC • Data decompressed and reformatted in near real-time by PI teams and posted on SOHO pages • More than 2/3 of over 2100 SOHO comets discovered by amateurs in SOHO real-time data • Final level-0 data produced by Data Distribution Facility with about 4 weeks delay • Most data gaps and drop-outs filled by then • Original distribution on CD-ROMs • Since 1997 distribution through Internet

22. Data accessibility • Completely open data policy • “The Sun is shining for everybody” • All SOHO data available online through • SOHO archive • PI sites • Virtual Solar Observatory • Instrument resources pages • Software tools (IDL) • Calibration • Analysis • Key element for prompt and expedient data delivery by PI teams is the fact that we do not require calibrated data for ingestion into archive, but raw data + calibration software (which can be easily updated)

23. SOHO Archive • Developed by ESA SOHO PS team at GSFC • Large variety of approaches in different PI teams • Difficult to homogenize system • Lesson learned: ESA involvement in planning process as early as possible • Content identical to that of PI teams • Exception: high-rate MDI data, which are stored only at Stanford • Current to within a few months after level-0 data deliver • (Incomplete) European Mirror archives • MEDOC, IAS Orsay, France • Univ. of Torino, Italy • RAL, UK • Lesson learned: very difficult for universities and other research groups to follow through on such a long-term commitment • New SOHO archive @ ESAC providing additional functionality • Efforts underway for “final archive” (calibrated data)

24. SOHO science operations NOW • Budget cuts necessitated radical changes to SOHO science ops starting in early 2010 • SOHO science ops now reduced to bare bones • Then: service in a 3-star restaurant Now: McDonalds drive-through • SOHO EOF closed; no routine planning meetings anymore • No SOC anymore • All “self-serve” by PI teams • Except LASCO/EIT all instruments are commanded remotely from home institutions • SOHO PS single point-of-contact

25. Summary • Ops concept developed in the early 90ies proved to be successful and robust • Science coordination key factor for the great success of SOHO • Having a real science center very beneficial for the mission and the community • No such focal point for STEREO, SDO or other planned solar missions • Early adoption of the World Wide Web as key tool for coordination, communication and data dissemination key decision • Maintenance of hardware/software infrastructure for 16+ years challenging • Open data policy to maximize the number of users • Provision of both data and software tools • No requirements on PI teams to provide final, calibrated, archive-quality data • “living” archive • Start planning of science operations and data archiving as early as possible • Work with instrument teams from very beginning of a project • Team spirit: integrated instrumenters/FOT/NASA/ESA team • Lights out ops working well so far

26. SOHO’s instruments