New Technologies for Exoplanet Detection with Mid-IR Interferometry Peter R. Lawson Oliver Lay,...

New Technologies for Exoplanet Detection with Mid-IR Interferometry

Peter R. Lawson

Oliver Lay, Stefan Martin, Robert Peters, Andrew Booth, Robert Gappinger, Alexander Ksendzov, and Daniel Scharf

Jet Propulsion LaboratoryCalifornia Institute of Technology

New Technologies for Probing the Diversity of Brown Dwarfs and Exoplanets

Shanghai, ChinaThursday, 23 July 2009

24 July 2009 - Shanghai, China P. R. Lawson, New Technologies for Exoplanet Detection with mid-IR Interferometers 2

Overview

Spectra of Earth-like exoplanets Architecture & Design Team Studies Technology Demonstrations Future Prospects Summary and Conclusion

Terrestrial Planet Finder

May 1999

McKee–Taylor Report: Decadal Survey 2000



Frank Selsis (Lyon)


Architecture Trades

and

Design Team Studies


TPF-Darwin Architecture Studies

Linear DCB

TPF-I Darwin

Bow-Tie

X-Array Planar TTN

Emma TTN

Emma X-Array

TPF-Darwin

Stretched X-Array


Properties of a TPF-I Observatory

Illustrative Properties of a TPF-I Observatory Concept

Parameter 4-Telescope Chopped X-Array Emma Design

Collectors Four 2-m diameter spherical mirrors, diffraction limited at 2 μm operating at 50 K

Array shape 6:1 rectangular array

Array size 400 × 67 m to 120 × 20 m

Wavelength range 6–20 µm

Inner working angle 13–43 mas (at 10 m, scaling with array size)

Angular resolution 2.4 mas to 8.2 mas (at 10 μm, scaling with array size)

Field-of-view 1 arcsec at 10 µm

Null depth 10-5 at 10 m (not including stellar size leakage)

Spectral resolution Δλ/λ 25 (for planets); 100 for general astrophysics

Sensitivity 0.3 µJy at 12 µm in 14 hours (5)

Target Stars 153 (F, G, K, and M main-sequence stars)

Detectable Earths 130 (2 year mission time, 1 Earth per star)

Exozodiacal emission Less than 10 times our solar system

Biomarkers CO2, O3 , H2O, CH4

Field of regard Instantaneous 45° to 85° from anti-Sun direction, 99.6% of full sky over one year.

Orbit L2 Halo orbit

Mission duration 5 years baseline with a goal of 10 years

Launch vehicle Ariane 5 ECA or equivalent


Mass estimates and launch packaging

3 m design = 6900 kg (w 30% reserve) Mass saving of 30% over previous

design Compatible with medium lift LV

– Delta IV M+

– Ariane 5 ECA

Scaling to smaller diameters– 3.0 m 6900 kg

– 2.0 m 4800 kg

– 1.5 m 4100 kg

– 1.0 m 3700 kg

Inspired by a design by Thales Alenia Space


Technology Demonstrations


Technology for a Mid-IR Interferometer Starlight suppression

– Null depth & bandwidth– Null stability

Formation flying– Formation control– Formation sensing– Propulsion systems

Cryogenic systems– Active components– Cryogenic structures– Passive cooling– Cryocoolers

Integrated Modeling– Model validation and testbeds

Science Requirements Architecture trade studies

Technology forStarlight and Noise Suppression

Spatial FilteringAdaptive Nulling

Array Rotation, Chopping, and AveragingSpectral Filtering


Single-Mode Mid-Infrared Fibers

Chalcogenide Fibers (NRL)– A. Ksendzov et al., “Characterization of mid-

infrared single mode fibers as modal filters,” Applied Optics 46, 7957-7962 (2007)

– Transmission losses 8 dB/m

– Suppression of 1000 for higher order modes

– Useable to ~11 microns

Silver-Halide Fibers (Tel Aviv Univ)– A. Ksendzov et al. “Modal filtering for mid-

infrared nulling interferometry using silver halide fibers,” Applied Optics 47, 5728-5735 (2008).

– Transmission losses 12 dB/m

– Suppression of 16000 possible with a 10-20 cm fibre, with aperturing the output.

– Useable to ~18 microns (?)

Example Chalcogenide Fibers, produced on contract by the Naval Research Laboratory

http://planetquest.jpl.nasa.gov/TPF-I/spatialFilters.cfm


Broadband Intensity and Phase Compensation

Parabolic mirror~ 10 x 14 cm

Uncompensatedbeam in (~4 cm)

Dispersive elementsplits wavelengths

Birefringent elementsplits polarizationsPupil

Stop

Compensatedbeam out (~4 cm)

PupilStop Birefringent element

re-combines polarizations

Dispersive elementre-combines wavelengths

S-polarization

Deformablemirror

P-polarization


TPF-I Milestone #1 and #3: Adaptive Nuller

Adaptive Nuller

– TPF-I Milestone #1 completed, July 2007

• Demonstrated 0.09% intensity compensation and 4.4 nm phase compensation

– TPF-I Milestone #3 completed, February 2009

• Demonstrated 1.0×10-5 mean null depth with a 34% bandwidth in three 6-hour experiments.

“Broadband phase and intensity compensation with a deformable mirror for an interferometric nuller,” R. D. Peters, O. P. Lay and M. Jeganathan, Applied Optics 47, 3920-3926 (2008).


100,000:1 with 34% Bandwidth, = 10 m


Chop, Rotate, Average, Spectral Fit


– Demonstrate array rotation, chopping, and averaging

– Detect planet signal at a contrast of ≤ 10-6 relative to the star

– Show residual starlight suppression from phase chopping and rotation ≥ 100.

– Tests run for a total duration of 10,000 s, with one or more rotations at timescales of ≥ 2000 s.

Planet Detection Testbed


Technology forFormation Flying

Guidance, Navigation & Control


Precision Formation Flying


Precision Leader-Follower Maneuver


TPF-I Milestone #2: Formation Control Testbed

TPF-I Milestone #2 experiments for the formation precision performance maneuver were completed 30 September 2007

Goal:Per axis translation control < 5 cm rmsPer axis rotation control < 6.7 arcmin rms Demonstrated with arcs having 20 and 40 degree chords. Experiments repeated three times, spaced at least two days apart.

Milestone Report published 16 January 2008

Formation Control Testbed

Example Milestone Data: Rotation maneuver with 20 degree chord segments

x axis 2.66 arcmin rmsy axis 2.93 arcmin rmsz axis 1.67 arcmin rms

x axis 4.77 arcmin rmsy axis 5.14 arcmin rmsz axis 2.70 arcmin rms

x axis 1.39 cm rmsy axis 2.41 cm rms

Relative path of robots for an arc with 20 degree chords


Recent Advances in Formation Flying

Orbital Express (DARPA) May-July 2007– Demonstrated in-orbit servicing of satellites

– Relative maneuvers of two satellites

– Transfer of liquids and batteries

Autonomous Transfer Vehicle (ESA) April 2008– Unmanned transport to the International Space

Station

– 10.3-m long and 4.5-m diameter

– GPS, video, and human supervision

– Two days of demos, and rendezvous and docking

– 30 September 2008, completed a destructive re-entry


Prisma (2009) and Proba-3 (2012) Prisma (Swedish Space Corporation) launch 24 November 2009

– Rendezvous and docking demonstrations

– Prototype “Darwin” RF metrology

Proba-3 (ESA) 2012– 30-150 m separation for demonstrations

– Millimeter-level range control

– RF Metrology & Optical metrology

– AO for the provision of the coronagraph now out

• http://sci.esa.int/proba_3_AO

Prisma

Proba-3


Related New Technologies


Large Light-Weight Optics

Herschel Primary Mirror


CryocoolersAdvanced Cryocooler Technology

Development Program

JWST Cryocooler (NGST)

Technology Development in Europe Infrared Nulling testbeds (ESA)

– Thales Alenia Space

– EADS Astrium

– University of Delft

– Institut d’Astrophysique Spatiale Cryogenic Delay Line (ESA)

– TNO, The Netherlands

Integrated Optics and Fiber Optics (ESA)– LAOG, Université Joseph Fourier, Grenoble

– Thales Alenia Space

– EADS Astrium / TNO

– Université de Rennes

– Université de Montpellier Breadboard demonstrator for PEGASE (CNES) Cryogenic mid-IR testbed, Inst. Astrophysique Spatiale

(under design) RF Metrology for formation flying (Thales Alenia Space)24 July 2009 - Shanghai, China P. R. Lawson, New Technologies for Exoplanet Detection with mid-IR Interferometers 29

Thales Alenia Space

Inst. Astrophysique Spatiale

TNO


Interferometer Technology Metrics

Technology Specs Performanceto date

Performance target prior to

Phase A

FlightPerformance(preliminary)

Nulling

Averagenull depth

9.9x10-6 (34%BW)Milestone #3 1.0x10-5 1.0x10-5

Intensity control

0.09%Milestone #1 0.2% 0.13%

Phase control

4.4 nmMilestone #1 5.0 nm 1.5 nm

Stability timescale

21,600 sMilestone #1 5,000 s > 50,000 s

Bandwidth8.4-11.6 µm

(34%)Milestone #1

8.3 to 10.7 µm(25%) 7 to 17 µm

FormationFlying

Number of S/C 2 Robots 3 Robots 5 S/C

Relative control

1.4 - 4.6 cm range, 1σ(formation rotation)

Milestone #2

5 cm range, 1σ(formation rotation)

2 cm range

Accomplished1999–2009

31

Room-temperature experiments & ground-based

• Broadband mid-infrared starlight suppression has been demonstrated at flight performance levels using the adaptive nuller

• System-level planet detection has been demonstrated using the Planet Detection Testbed

• Formation Flying algorithms demonstrated with traceability to flight.

Related cryogenic technology

• Herschel mirror development

• Cryocooler work for JWST

• Cryogenic delay line development for ESA

3124 July 2009 - Shanghai, China P. R. Lawson, New Technologies for Exoplanet Detection with mid-IR Interferometers

Remaining2010–2020

Cryogenic engineering & space-based testing

• Demonstrate component, subsystem, and system performance in a cryogenic environment

• Demonstrate the detection of biosignatures

• Validate models of the observatory

• Complete integration and test plans

• Demonstrate space-based interferometry

• Demonstrate space-based formation flying

Further Reading

32

R. D. Peters, O. P. Lay, and M. Jeganathan, “Broadband phase and intensity compensation with a deformable mirror for an interferometric nuller,” Applied Optics 47, 3920–3926 (2008)

A. Ksendzov, et al., “Modal filtering for mid-infrared nulling interferometry using single-mode silver halide fibers,” Applied Optics 47, 5728–5735 (2008)

A. Ksendzov, et al., “Characterization of mid-infrared single mode fibers as modal filters,” Applied Optics 46, 7957–7962 (2007)

R. O. Gappinger, et al. “Experimental evaluation of achromatic phase shifters for mid-infrared starlight suppression,” Applied Optics 48, 868–880 (2009)

32

http://planetquest.jpl.nasa.gov/TPF-I/

This work was conducted at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

24 July 2009 - Shanghai, China P. R. Lawson, New Technologies for Exoplanet Detection with mid-IR Interferometers


Backup Slides


Terrestrial Planet Finder Interferometer

Salient Features• Formation Flying Mid-IR nulling

Interferometer • Starlight suppression to 10-5 • Heavy launch vehicle• L2 baseline orbit• 5 year mission life (10 year goal)• Potential collaboration with

European Space Agency

Science Goals• Detect as many as possible Earth-like planets in the “habitable zone” of nearby stars via

their thermal emission• Characterize physical properties of detected Earth-like planets (size, orbital parameters,

presence of atmosphere) and make low resolution spectral observations looking for evidence of a habitable planet and bio-markers such as O2, CO2, CH4 and H2O

• Detect and characterize the components of nearby planetary systems including disks, terrestrial planets, giant planets and multiple planet systems

• Perform general astrophysics investigations as capability and time permit

State of the Art in Nulling Interferometry

24 July 2009 - Shanghai, China 35P. R. Lawson, New Technologies for Exoplanet Detection with mid-IR Interferometers

New Technologies for Exoplanet Detection with Mid-IR Interferometry Peter R. Lawson Oliver Lay,...

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