1

SOFIAStratospheric Observatory

For Infrared Astronomy

Jon Morse / Ray Taylor

NASA Program Executive

May 11, 2007

2

Outline of Material

• Overview of SOFIA

• Progress to Date

• Science

• Operations Plans

• Schedule

3

OVERVIEW

4

Overview of SOFIA

• SOFIA is 2.5 m telescope in a modified B747-SP aircraft– Optical-mm performance– Obscured IR (30-300 m) most important

• Operating altitude– 39,000 to 45,000 feet (12 to 14 km)– Above > 99% of obscuring water vapor

• Joint Program between the US (80%) and Germany (20%)• First Light Science 2009 (NASA, DLR, USRA, DSI)

– Designed for 20 year lifetime– Deployments– Ramp up to goal of 120 flights per year of 8 to 10 Hours– Build on KAO Heritage

• Science flights to originate from NASA Dryden Flight Research Center (DFRC)– DFRC is where many other NASA research aircraft are located

• Science Center is located at NASA Ames Research Center

5

6

PROGRESS TO DATE

7

Telescope Installed

8

Main Deck, Looking Aft at Instrument Interface

Orange Color is Flight Test Instrumentation

Telescope Pointing Control Electronics to the Left

9

Instrument Interface

Blue is DLR Supplied Equipment

White is New Pressure Bulkhead

10

First Flight (April 2007)Waco, TX

11

As an airborne mission, SOFIA supports a unique, expandable instrument suite

• SOFIA covers the full IR range with imagers and low, moderate, and high resolution spectrographs

• 4 instruments at Initial Operations; 9 instruments at Final Operations.

• SOFIA can take fully advantage of improvements in instrument technology

• Both Facility and PI Instruments

• Germany is supplying two of the generation instruments (GREAT & FIFI-LS)

SOFIA’s Instrument Complement

12

Working/complete HIPO instrument in Waco on SOFIAduring Aug 2004

Working/complete FLITECAM

instrument atLick in 2004/5

Working FORCAST instrument at Palomar in 2005

Successful lab demonstration of

GREAT in July 2005

Three of Seven U.S. InstrumentsOne of Two German Instruments

13

First Light Tracking: <0.8 arcsec rms from ground

Tracker in centroid inertial tracking mode

500

510

520

530

540

550

550 560 570 580 590 600

Series1

(September 2004)

14

SCIENCE

15

Science Capabilities

• Because of large aperture and better detectors, sensitivity for imaging and spectroscopy similar to the space observatory ISO

• 8x8 arcmin Field of View allows use of very large detector arrays

• Image size is diffraction-limited beyond 25 µm, making it 3 times sharper than the space observatory Spitzer at these wavelengths

16

Astrochemistry• Most molecular lines in IR or

submillimeter• Need high spectral resolution

throughout IR and submillimeter

• As sensitive as CSO, but complete wavelength range is accessible (ie. H2, C2H2,CH4 only in IR)

• Light molecules: Hydrogen, water, other hydrides in IR and submillimeter

• HD at 112 microns

• The fullerene, C60, has 4 IR lines in SOFIA’s bands

CSO FTS Spectrum of ORION OMC1

Serabyn and Weisstein 1995

17

Occultation astronomy with SOFIA

Pluto occultation lightcurve observed on the KAO (1984) probes the atmosphere

• SOFIA can fly anywhere on the Earth, allowing it to position itself under the shadow of an occulting object

• Occultation studies with SOFIA will probe the sizes, atmospheres, and possible satellites of Kuiper belt objects and newly discovered planet-like objects in the outer Solar system. The unique mobility of SOFIA opens up some hundred events per year for study compared to a handful for a fixed observatory.

• SOFIA’s mobility also enables study of comets, supernovae and other serendipitous objects

SOFIA will measure stellar occultations

18

One of the major discoveries of the KAO was a ring of dust and gas orbiting the very center of the Galaxy

Astronomers at ESO and Keck detected fast moving stars revealing a 4 x 106 solar mass black hole at the Galactic Center

Feeding the Black Hole in the Center of the Galaxy

• The ring of dust and gas will fall into the black hole

• SOFIA’s angular resolution and spectrometers will tell us:– How much matter gets fed into the black hole?– How much energy is released?– What is the relationship to high energy active galactic nuclei?

19

Atmospheric transmission around the HD line at 40,000 feet

Only the high resolution spectrograph on SOFIA can measure the deuterium abundance throughout our galaxy and answer:

• What is the abundance of deuterium and how does it vary with the local star formation rate in galaxies?

• What does that tell us about the Big Bang and about the star formation history of galaxies?

• As pointed out by Bergin, Hollenbach and others, HD can also give the Molecular Hydrogen abundance. NASA strategic sub-goal 3D.1 and 3D.2

Deuterium in the universe is created in the Big Bang and the primordial deuterium abundance provides the best constraints on the mass density of baryons in the universe. However, this Big Bang record is subsequently modified by stellar nuclear burning as material cycles from stars to the interstellar medium and back to stars.

SOFIA will study the deuterium abundance in the galaxy, investigating the evolution of the universe

Evolution of the Universe

20

Operations Plans

21

SOFIA Operations Drivers

• Frequent Flights: Ramp Up to 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

22

SOFIA Science Operations• SOFIA will be operated as an observatory open to the whole science

community through peer review• Ramp Up to 3 flights a week for ~40 weeks per year• On-going independent review of SOFIA science operations

– Gary Melnick, Chair• Flights will be primarily out of Dryden (Edwards AFB) 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

• 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

23

Schedule

24

SOFIA Schedule (Major Milestones)

Completed

• First Re-Flight April ‘07

Upcoming

• Ferry Flight to DFRC June ‘07

• Initiate Closed Door Flight Tests Fall ‘08

• Complete Closed Door Flight Tests Summer ‘08

• Install Door Drive (and other work) Fall/Winter ‘08

• Initiate Open Door Flight Tests Spring ‘09

• First Science ‘09

25

SOFIA FY08 FY09 FY10 FY11 FY12

Total 77.3 89.1 88.6 89.9 92.1

FY08 Budget Request

26

Summary

- Aircraft structural modifications complete- Telescope installed, several instruments tested on ground observatories- Several subsystems to be installed (e.g., door drive)- Completed first flight, leading to ferry flight in June ‘07 to DFRC- Full envelope flight testing (closed door) to start in Fall ’08- First science in ’09- SOFIA will be one of the primary facilities for far-IR and sub-millimeter astronomy for many years

27

Back-up

28

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.

29

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

30

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 5 to 28 micron region

31

• Atmosphere: above 99% of the water vapor

• IR transmission at 14 km >80% from 1 to 800 m

• Instrumentation: wide variety, rapidly interchangeable, state-of-the art

• Mobility: anywhere, anytime

• Long lifetime

• A near-space observatory that comes home after every flight

Why SOFIA?

32

NEXT CALL FOR NEW INSTRUMENTS

• The next call for instruments will be at first Science ~FY10

• There will be additional calls every 3 years

• There will be one new instrument or upgrade per year

• Approximate funding for new instruments $8 M/yr

33

Frequency (THz)

2005 2010 2015 2020 2025

SOFIA

30

3

0.3

Wavelength (µm)SPITZER

1000

100

10

1

Infrared Space Observatories

He

rsch

el

SA

FIR

Ground-based Observatories

JWST

?

SOFIA provides temporal continuity and wide spectral coverage, complementing other infrared observatories.