SOFIA Stratospheric Observatory For Infrared Astronomy

2. SOFIAStratospheric Observatory For Infrared Astronomy E. E. Becklin SOFIA Chief Scientist AAS WORKSHOP Jan 7, 2007

3. Outline • Overview of SOFIA • Progress to Date • Science Capabilities • Schedule

4. OVERVIEW OF SOFIA

5. Overview of SOFIA • SOFIA is a 2.5 m telescope in a modified B747SP aircraft • Optical to mm wavelength performance • Obscured IR range (30-300 m) is most important • Joint Program between the US (80%) and Germany (20%) • First Science 2009 (NASA, DLR, USRA, DSI) • Designed for 20 year lifetime

6. Overview of SOFIA (continued) • Operating altitude: • 39,000 to 45,000 feet (12 to 14 km) • Above > 99% of obscuring water vapor • World-wide deployments • Ramp up to ~1000 science hours per year • Build on KAO Heritage with improvements • Facility Instruments • Science support • Science flights to originate from Palmdale Site 9 run by DFRC • Science Center is located at NASA Ames Research Center

7. SOFIA — The Observatory open cavity (door not shown) Educators work station pressure bulkhead scientist stations, telescope and instrument control, etc. TELESCOPE scientific instrument (1 of 9)

8. Infrared transmission in the stratosphere very good: Average > 80% from 1 to 1000 microns Instrumentation: wide complement, interchangeable, state-of-art Mobility: anywhere, anytime Long lifetime Outstanding platform to train future instrumentalists Why SOFIA?

9. PROGRESS TO DATE

10. SOFIA’s First Flight - 26 April, 2007

11. Major Physical Installations Completed Main deck, looking aft at instrument interface Telescope installed

12. Primary Mirror (uncoated)

13. Telescope in Action

14. SOFIA’s Instrument Complement • As an airborne mission, SOFIA supports a unique, expandable instrument suite • SOFIA covers the full IR range with imagers and low- to high-resolution spectrographs • FORCAST and GREAT for • Early Science in 2009 • FIFI-LS, HIPO and FLITECAM in 2010 • All 9 instruments by ~ 2012. • SOFIA will take full advantage of improvements in instrument technology. There will be one new instrument or major upgrade each year.

15. Working/complete HIPO instrument in Waco on SOFIA during Aug 2004 Working/complete FLITECAM instrument at Lick in 2004/5 Working FORCAST instrument at Palomar in 2005 Successful lab demonstration of GREAT in July 2005 Four First Light Instruments

16. SCIENCE CAPABILITIES

17. Science Capabilities • Because of large aperture and better detectors, sensitivity for imaging and spectroscopy similar to the space observatory ISO. • > 8 arcmin field-of-view allows use of very large detector arrays. • Image size is diffraction-limited beyond 25 µm. • Theta(FWHM) ~ Lambda(microns) / 10 arcsec

18. Herschel Spitzer

19. Angular Resolution

20. Other Science Capabilities • Primary Mirror diameter 2.7 meters. Use the central 2.5 meters. • Secondary Chopper: 8 arcmin peak-to-peak, f ~ 20Hz • Background:  ~ 0.1, T ~ 240 K • Telescope elevation range is 20 to 60 degrees • Instruments are accessible

21. SOFIA Advances Other Major Missions • Spitzer: SOFIA has 3 times higher angular resolution beyond 25 microns. Higher spectral resolution. Capabilities beyond 160 microns. • Herschel: SOFIA has capabilities below 60 microns. Higher spectral resolution below 150 microns (2 THz). Much longer life time and advanced Instruments (large arrays and higher sensitivity). • JWST: SOFIA has capabilities beyond 28 microns. Higher spectral resolution from 5 to 28 microns. • ALMA: SOFIA has capabilities below 300 microns and between 500 and 600 microns.

22. 1000 0.3 ? SAFIR Frequency (THz) Herschel SOFIA 100 3 JWST SPITZER Wavelength (µm) 10 30 1 2005 2010 2015 2020 2025 Infrared Space Observatories Ground-based Observatories SOFIA provides temporal continuity and wide spectral coverage, complementing other infrared observatories.

23. SCHEDULE

24. SOFIA Schedule (Major Milestones) • First Re-Flight Occurred April ‘07 • Ten Closed Door Flights Finished Dec ‘07 • Door Drive Delivered Spring ‘08 • Mirror coated and ground tests Spring/Summer 08 • Open Door Flights at Palmdale Fall ‘08 • First Science ‘09 • Next Instrument call ‘10

25. Early Science US General Observer Opportunities • First call Early Science proposals this year • Early Short Science Aug ‘08 with PI’s • Early Basic Science Dec ‘08 GO’s • Early Short Science with FORCAST and GREAT • Special call for participation with PI’s • Very limited flights (~3) • GO’s will not fly • Early Basic Science also with FORCAST and GREAT • Longer period (~15 Flights) • More capabilities • Call will be for GO Science and GO participation

26. US General Observer Opportunities in 2010 and Beyond • There will be a GO call in FY 2010 for the 5 first Science Instruments. (FORCAST, GREAT, FIFI-LS, FLITECAM and HIPO) • FORCAST, FLITECAM and FIFI-LS will be facility or “facility like instruments” Do not need to be an IR specialist. Data Pipelines. Archive. Science Support on the Flight. • GO’s work with the PI for PI instruments • There will be about $3m/ year for GO support for data reduction

27. Next Call for New Instruments • The next call for instruments will be at First Science ~ FY ‘10 • We are considering: • New science instruments, both FSI and PSI • Studies of instruments and technology • Upgrades to present instruments • There will be additional calls every 3 years • There will be one new instrument or upgrade per year • Approximate funding for new instruments and technology is ~$10 M/yr

28. Summary • Program making progress! • Aircraft structural modifications complete • Telescope installed, several instruments tested on ground observatories • Completed first flight and ferry flight to NASA Dryden • Full envelope flight testing (closed door) 80% complete. • Several subsystems will be installed spring/summer 08 (door motor drive, coated primary mirror) • First science in ’09 • SOFIA will be one of the primary facilities for far-IR and sub-millimeter astronomy for many years

29. BACK-UP

30. OPERATIONS PLANS

31. SOFIA Operations Drivers • Frequent Flights: 960 science hours/year (2x KAO) • World-wide deployments especially to the Southern Hemisphere will be scheduled as required by science • Both Facility and PI Instruments • Facility Instruments: Good tools, Data Pipelines and Archive - easy for non-IR astronomer to obtain good data (New for Airborne Astronomy with SOFIA) • PI Instruments: State of the art and innovative • General Investigator program for both FSI and PI, with funded research • Robust Instrument program to allow Observatory to “reinvent itself” every few years • Unique Education and Public Outreach program

32. SOFIA Science Operations • SOFIA will be operated as an observatory open to the whole science community through peer review • 3 flights a week for ~40 weeks per year • Flights will be primarily out of SOFIA Operations Center at Palmdale Airport near Dryden with occasional deployments to the southern hemisphere and other sites as needed • Continuous access of science and mission staff to airplane • Preflight instrument simulator facilities (testing and alignment) for mission preparation • Instrument laboratories including cryogen facilities • Rapid instrument exchange • SOFIA Science Center will be at Ames • Telescope time peer review • Observing time schedule • Flight planning • Management of Instruments (Operations and Development) • Science Data Archive(Facility Instruments Reduced data, PI raw data) • Observing Support

33. SOFIA and Spitzer • SOFIA will become operational near the time that Spitzer runs out of cryogens. The science impact of not being contemporary is small: Spitzer is a high sensitivity imaging and low resolution spectroscopy mission. SOFIA is a high spectral and high angular resolution mission • As it now stands, the two observatories are very complementary and when Spitzer runs out of cryogens in early FY09, SOFIA will be the only observatory working in the 25 to 60 micron region for over 10 years: Comets, Supernovae, Variable AGN, other discoveries.

34. SOFIA and Herschel • Herschel and SOFIA will now start at about the same time • Joint calibration work is on going • For the years of overlap, SOFIA will be only program: • with 25 to 60 micron capability • with high resolution spectroscopy in the 60 to 150 micron region • When cryogens run out in Herschel in ~2011 SOFIA will be only NASA mission in 25 to 600 micron region for many years • Important follow-up • Advanced instrumentation will give unique capabilities to SOFIA: Polarization, Heterodyne Arrays, Heterodyne Spectroscopy at 28 microns (ground state of molecular hydrogen), and other interesting astrophysics lines • Both missions are critically important and complementary

35. SOFIA and JWST • SOFIA is very complementary to JWST • Before JWST is deployed and after Spitzer cryogens run out , SOFIA is only mission with 5 to 8 micron capabilities • important organic signatures • After JWST is launched SOFIA is the only mission to give complementary observation beyond 28 microns and high resolution spectroscopy in the 5 to 28 micron region

36. SOFIA and WISE • WISE is a very sensitive all sky survey in the 3.3 to 23 micron region. It is expect to launch just as SOFIA begins operations. • SOFIA can provide a number of important follow-up observations. • Very red sources seen only at 23 microns can be followed up at 38 microns with FORCAST on SOFIA and spectra can be obtained with EXES on SOFIA for the brightest 23 micron sources not seen by IRAS. • Nearby cold Brown Dwarfs discovered by WISE can be followed up with the FLITECAM GRISM and EXES.