Astronomers Returns to the Stratosphere

Presenter: Name 1

NASA ARC - AIAASeptember 14, 2010

Moffett Field, CA

Presented BySean C Casey

Universities Space Research [email protected]

Stratospheric Observatory forInfrared Astronomy (SOFIA)

Presenter: Sean C. Casey 2

Talk Outline

• Introduction on Airborne Astronomy• Construction of the observatory• SOFIA’s expected science return• Summary


Astronomy in the Infrared

• Astronomical observatories throughout the EM spectrum• Wavelength is indicative of the energetics

Optical


Friedrich Wilhelm Herschel 1738 - 1822

The 18th Century Discovery of Infrared Radiation (IR)

Discovered theplanet Uranus!


21st Century Imaging in the Optical and Infrared

Optical

(What your eye does see.)

Infrared

(What your eye does not see.)

A Collard Lizard


Astronomy in the Optical and Infrared

Cooled gas and dust emission at T = 10’s – 100’s K


Interstellar Dust

Carbonaceous and Silicate condensates of the ISM.Particle size produces selective extinction (s+a).


Looking toward the center of our GalaxyOptical Image

Near-Infrared

Far-Infrared

• Imaging at longer wavelengths– Optical shows only cloud surfaces– Infrared provides diagnostics of obscured environments


Lifecycle of the ISM

X. Tielens 2006


Atmospheric Absorption

0.0

0.2

0.4

0.6

0.8

1.0

145 150 155 160 165

C+

R ~ 10,000Observations within the 30 – 300 micron window are only possible from the stratosphere and above.


Previous and Existing IR Observatories

Ground-based Sub-orbital

IRAS COBE ISO SIRTF

Space-based

KAOMauna Kea


Kuiper Airborne Observatory : 1974 - 1995>300 investigators, ~50 PhDs, ~40 instruments, ~9000 observing

hours

Important Science results:- Life cycle of gas and dust in the ISM- Recognition of photo-dissociation regions- Numerous far-IR lines OI, CII, FeIV

- PAH emission characteristics- Far-Infrared polarization- Ring of Uranus

Set the scientific stage for the infrared missions: IRAS, ISO, and Spitzer


Typical instrumentation aboard KAO

Pre-flight checkoutof FIFI on the KAOby A. Poglitsch andTeam (Genzel et al.).

Successful developmentand use of stressed/unstressed germanium photo-conductors in far-IR.

Successful Internationalparticipation


Astronomy aboard an Airplane

A. Krabbe and H-P. Roeser 1999 “SOFIA Astronomy and Technology in the 21st Century”


Flight Profiles – Start at 37,000 Feet

• Some research flights may reach duration of 10.5 Science Hours

START, TAXI, TAKEOFFGW 648.0

CRUISE108,000 LBS. FUELF.F. 22,520 LBS/HR4.6 HRS.

37,000 FT.GW 628.0

CRUISE40,000 LBS. FUELF.F. 19,480 LBS/HR.1.9 HRS.

CRUISE40,000 LBS FUELF.F. 18,380 LBS/HR.2.05 HRS.

CRUISE35,000 LBS. FUELF.F. 16,920 LBS/HR.2.05 HRS.

TOTAL FUEL USED – 268,000 LBS.TOTAL CRUISE TIME – 10.6 HRS.

TOTAL FLIGHT TIME – 11.9 HRS.

ASSUMPTIONS

ZFW 380,000 LBS.20,000 LBS. FUEL TO FIRST LEVEL OFFCLIMB TO FIRST LEVEL-OFF AT MAX CRUISE WTSTAY AT ALT. UNTIL FUEL FLOW IS LESS AT STEP CLIMB ALT.1 HRS.FOR EACH STEP CLIMBLANDING WITH 20,000 LBS. FUELBASED ON 747 SP FLIGHT MANUAL TABULATED DATASTANDARD DAY PLUS 10 DEGREES CSPEED-MACH .84

39,000 FT.GW 520.0

41,000 FT.GW 480.0

43,000 FT.GW 440.0

DESCENTGW 405.0

5,000 LBS. FUEL

.5 HRS.

LANDINGGW 400.0

CLIMB.5 HRS.


Stratospheric Observatory For Infrared Astronomy

747-SP “Clipper Lindbergh”

Aircraft flight tests, circa 1997/8


SOFIA Attributes

- Wavelength range: “UV to Radio”: 0.3 – 1600 µm

- Mobility: “anywhere, any time”: all sky, ephemeral events

- Primary Mirror: 2.7 m diameter (Aperture 2.5 m)

- Operating Altitude: 12 – 14 km (37,000 - 45,000 feet)

- Design Lifetime: 20 years

- Observing Program: flexible; annual proposal opportunities

- Science Instruments: wide variety, hands-on in-flight, late

latest technologies in new instruments

- Young researchers’ opportunities: scientists and instrumentalists

- Education/Public Outreach: teachers/media/publicSOFIA will be a mobile modern observatory

in the lower stratosphere.


Angular resolution of SOFIA

HST in optical KAO at 60 µm

SOFIA: KAO Comparison - almost 9 SOFIA beams for every 1 KAO beam

Orion in Optical and Far-infrared


Education & Public Outreach Section

Mission Control & Science Operation Section

Pressure Bulkhead

Telescope Cavity Door

ScienceInstrument

Cavity Environmental Control System

Telescope 2.7m

SOFIA’s Interior Layout

Open Port Cavity


SOFIA’s Optical Layout


Photometric Sensitivity and Angular resolution

SOFIA is diffraction limited beyond 25 µm (θmin ~ λ/10 in arcseconds) and can produce images three times sharper than those made by Spitzer

SOFIA is as

sensitive as ISO


SOFIA’s Operational Phase Space


10 0

10 1

10 2

10 3

10 4

10 5

10 6

10 7

10 8

1 10 100 1000Wavelength [µm]

Sp

ectr

al r

esol

uti

on

HIPO

FLITECAM

FORCAST

EXES

HAWC

SAFIREFIFI LS

GREAT

CASIMIR

Planetary AtmospheresPlanetary Atmospheres

Planetary AtmospheresPlanetary Atmospheres

Chemistry of the cold ISMChemistry of the cold ISM

Comet MoleculesComet Molecules Dynamics of the Galactic CenterDynamics of the Galactic Center

Dynamics of collapsing protostarsDynamics of collapsing protostars

Velocity structure and gas composition in Velocity structure and gas composition in disks and outflows of YSOsdisks and outflows of YSOs

Composition/dynamics/physics of the Composition/dynamics/physics of the ISM in external galaxiesISM in external galaxiesPAH & organic moleculesPAH & organic molecules

Nuclear synthesis in supernovae in nearby galaxiesNuclear synthesis in supernovae in nearby galaxies

Composition of interstellar grainsComposition of interstellar grains

KBOs, Planet TransitsKBOs, Planet TransitsDebris Disk StructureDebris Disk Structure

Luminosity and Morphology of Star Formation Galactic Luminosity and Morphology of Star Formation Galactic and Extra-Galactic Regionsand Extra-Galactic Regions

SOFIA Science is broadly based


Current Instruments

Early Science SIs


SOFIA Instruments

#1

#2

Working/complete HIPO instrument at Lowell Obs. Aug 2004

Working/complete FLITECAM instrument atLick in 2004/5

Working FORCAST instrument at Palomar in 2005

Successful lab demonstration of GREAT in Oct 2005

HAWC flight cryostat testing at Yerkes in 2005

Early science instruments:FORCAST/GREAT


FORCAST: Mid-IR Imager

PI: T. Herter (Cornell Univ.) [email protected]

Detectors: Dual channel 256 x 256 arrays; 5 – 25 m (Si:As) 20 – 40 m (Si:Sb)

Field of View: 3.2’ x 3.2’

Science: Thermal and narrow band imaging

Targets: Circumstellar disks, Galactic Center,Galactic and extragalactic star formation

NB: Diffraction Limited > 15 microns; Grism upgrade funded (Ennico 2005)

Working FORCAST instrument at Palomar in 2006


GREAT: Heterodyne Spectrometer

PI: R. Guesten, Max-Planck Institut, [email protected]

R= 106 -> 108

Detector: dual channel mixer (HEB);60 – 200 m (2 – 5 THz)

Science: Spectroscopy of CII (158 m), and HD (112 m)

Targets: Galactic and extragalactic ISM, circumstellar shells

Successful lab demonstration of GREAT in Oct 2005

NB: TA ~ 2500 K at 158 m

High frequency upgrade at 4.7 THz expected for OI (63 m).

Field of View: single element


SOFIA Aircraft: 747 SP #21441 as proposed by USRA

Christened the “Clipper Lindbergh”by Anne Morrow Lindberghin May 1977 on the 50th anniversary of Lindbergh’s flight across the Atlantic.

Juan Trippe andCharles Lindberghwith Pan Am inmid-1930’s.

Summer ‘97

Observatory Hardware


2.7 M

Primary Mirror, f/1.28 at SAGEM, circa 2000

RMS = 280 nm


Aircraft pressure bulk head ’01 (assembly) ’02 (installation)


Build-up of the DLR telescope components in Germany.

Complete telescope assembly (TA) run with closed-loop servo control using the hydrostatic bearing and gyroscopic control.

Telescope metering structureScience Instrument end of TA

March ‘02


Telescope arrives in Waco, TX Sept. ‘02


July ’03 – primary mirror installed


August ’03 – Telescope installation complete


March ’04 – Proof pressure test

SOFIA passes test!


February ‘05 – Test of landing gear


February ‘06 – Aircraft aperture door complete


SOFIA Instrument Flange


SOFIA’s Interior

Aircraft interior Sept. 06


SOFIA with NASA colors


SOFIA is Airborne in 2007


SOFIA at ARC in 2007


SOFIA at NASA Dryden


Uncoated Telescope/Incomplete Door


Finishing the Door


A coated primary mirror


Optical telescope tests with HIPO team


SOFIA Line-Op


Telescope Testing


Telescope Close-up


Telescope for Test Flights


FORCAST on SOFIA


SOFIA First Light - Jupiter


Will SOFIA reveal debris disks @ 37 m?

Wilner et al. model of Vega predicts resolved structure when convolved with SOFIA resolution @ =37 m (LEFT), but Spitzer finds Fomalhaut (RIGHT) and Vega (not shown) amorphous at =24 m. Due to small grains or small inner disk radius?? - ask SOFIA!

?

Vega model SOFIA @37 m Fomalhaut Spitzer MIPS @24 m

72"

FORCAST beam size at 37 m


Malfait et al. 1998Debris Disk Evolution

VegaFomalhaut Beta Pic


Segregation of gas & ices around protostars

van Dishoeck & Hogerheijde 1999

W33AGibb et al. 2000

R~2000 FLITECAM and FORCAST (with grisms) observations can reveal constituents & chemistry of protostellar envelopes (except for CO2).


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


Transits of Extrasolar Planets

• SOFIA will fly above the scintillating components of the atmosphere and will be the most sensitive freely pointing observatory for extrasolar planetary transits after HST.

• SOFIA will be able to detect weak transit signals with high signal-to-noise, conclusively determining the status of candidate extrasolar planets discovered by transit surveys: long life needed!

HD 209458 artist’s concept (left) and HST STIS data (below)


The ground-based infrared spectrum of Mars is dominated by broad lines in the Earth atmosphere. A weak feature on the wing of the strong terrestrial methane line may be the Doppler-shifted methane line in the Mars atmosphere. If true, the methane abundance is very high and may reflect biogenic activity.

The high resolution spectrograph on SOFIA can probe between the much narrower terrestrial lines at airborne altitudes and uniquely address:

• Is there methane in the Martian atmosphere?

• If so, where does it come from? What is it global distribution? How does it vary with the seasons on Mars?

SOFIA will study planetary atmospheres

Planetary Atmospheres


Phillips 1988

Astrochemistry

• Most molecular lines in IR or submillimeter– Need high spectral resolution

throughout the submillimeter

• As sensitive as CSO, but complete wavelength range is accessible– H2, C2H2,CH4 only in IR

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

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

• HD at 112 microns


Evolution of the Universe

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?

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


SOFIA’s Next Steps

• Short Science Flights– FORCAST – Oct 2010 (3 flights)– GREAT – Feb 2010 (3 flights)

• Basic Science Program (50+ proposals)– Shared risk flights with FORCAST & GREAT– Summer 2011 (20 flights)

• Completion of observatory updated– 2011 – 2012 (down time)

• Full Operating Capabilities– 2013 & beyond (working to 100+ flights/year)


Science and Instruments

• SOFIA offers unique capabilities within NASA– Serving two communities

• Instrument developers – offers a robust instrument program

• General Investigators – access to latest technologies

– Capable sub-orbital platform• Daily, weekly, monthly, yearly access to observatory• Ready access to science instruments• Track record for new technologies

• Science instrument development is an essential element of successful SOFIA operations.


Summary of SOFIA Goals

• Science: Provide high angular and

spectral resolution imaging through-out

the infrared and sub-millimeter.

• Technology: Provide a well calibrated

and understood platform for state-of-

the-art infrared and sub-millimeter

instrumentation.

• Education: Provide readily accessible

educational and public forums which

encourage the study of astronomy.

http://sofia.arc.nasa.gov


Additional Material


1988 Kuiper Airborne Obs.6 x 6 Bolometer Camera

1994 South Pole128 x 128 Si:Sb BIB Spectrometer

1997 Apache Point Obs.1024 x 1024 InSb Camera

Historical photos


Organic Growth & Chemistry in the ISM

Formation Processing Fossil / Delivery


Telescope for Astronomy


SOFIA First Light – M82


SOFIA Science is broadly based

• Star formation, dynamics and chemical content of other galaxies:

• Interstellar cloud chemistry and dynamics, and star and planet formation in our galaxy:

• The dynamic activity in the center of our own galaxy:

• Origin and evolution of biogenic materials in the interstellar medium and in proto-planetary disks:

• Comets, planet atmospheres and rings in our solar system:


GREAT: Heterodyne Spectrometer

PI: R. Guesten, Max-Planck Institut, [email protected]

R= 106 -> 108

Detector: dual channel mixer (HEB);60 – 200 m (1.4 - 5THz)

60 - 300 µm

Science: Spectroscopy of CII (158 m), and HD (112 m)

Targets: Galactic and extragalactic ISM, circumstellar shells

Successful lab demonstration at 1.9 THz of GREAT in July 2005

NB: TA < 2500 K at 158 m High frequency upgrade at 4.7 THz expected for OI (63 m).

Field of View: single element


Science Capabilities

• Sensitivity– Telescope

Emissivity ~ 0.1

Temperature ~ 240 K

– 40 to 300 m• ~ ISO point source (both

imaging and spectroscopy)

– 5 to 40 m• ~ 8 meter ground-based

telescope at 20m

• FOV 8 arcmin diameter• Image Size

– > 15 m: diffraction limited: 3 times better than Spitzer

(FWHM) ~ (m) / 10”


SOFIA, Herschel, and JWST

2008-2012

2014-2019


HIPO: High Speed Imager

PI: T. Dunham (Lowell Observatory) [email protected]

Detector: Dual channel 1Kx1K CCDs

Field of View: 5.6’ x 5.6’#1

#2

Working/complete HIPO instrument atLowell Obs. Aug 2004

Science: Occultations

Targets: Pluto, Triton, KBOs.

NB: Co-mounts w. FLITECAM


August ’04 – Optical telescope tests with HIPO team


NASA technology readiness level (TRL)

• Technology readiness defined– NASA/DOD– 9 levels

• Technology migration is an issue– Science enabling technologies are

essential to future NASA missions– Diminishing funds at the lowest and

highest levels create the “mid-TRL desert”

• Mitigation of new technology risks– Missions invest in critical technologies

• Spitzer - IRAC bridge chips• JWST - micro shutters arrays• Herschel - mixers/local oscillators

– System level integration is an issue• Converting photons into published results


SOFIA Instrument Definitions

• Principal Investigator Science Instruments (PSI)– Cutting edge technologies (low-TRL)– Developed and operated by PI teams– General investigators work with PI teams

• Facility Science Instrument (FSI)– Mature technologies (mid-TRL) when possible– Developed and delivered by PI teams– General investigators work with Observatory staff

• SOFIA must balance PSI and FSI programs– New SI, existing SI upgrades, & focused technology

development


HIPO: High Speed ImagerPI: T. Dunham (Lowell Observatory)

[email protected]

Detector: Dual channel 1Kx1K CCDs

Field of View: 5.6’ x 5.6’ #1

#2

Working/complete HIPO instrument atLowell Obs. Aug 2004

Pluto occultation from KAO (Elliot, et al. 1989)

Science: Occultations

Targets: Pluto, Triton, KBOs.

NB: Co-mounts w. FLITECAM


FLITECAM: Near-IR Imager

PI: I. McLean (UCLA) [email protected]

Detector: Single 1K x 1K array; 1-5 m (InSb)

Field of View: 8.2’ x 8.2’

Science: Imaging, Spectroscopy,Occultations

Targets: Galactic, extragalactic

Grism observations from Lick of NGC 7027

NB: SOFIA seeing limits (129.01)

Working/complete FLITECAM instrument atLick in 2004/5

R ~ 2000

Astronomers Returns to the Stratosphere

Technology

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