Darwin/ Xtrasolar AlbaNova 1 December 2005 p 1

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 2 Darwin and the Origins of Extrasolar Species Rene´ Liseau Stockholm Observatory Delegate to the Scientific Advisory Teams of ESA : TE-SAT NASA : TPFI-SWG

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 3 Outline Astronomical Jargon, Definitions & Acronyms Extrasolar Planets (known) Extrasolar Planets (expected) Detection Techniques (known possibilities) Detection Techniques (selected: ESA – Darwin, NASA – TPFI) Optical Architecture (destructive interference, formation flying) Mission Characteristics (payload, launcher, orbit selection) The Future (future missions)

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 4 Astronomical Jargon Sorry, if too trivial... : shall attempt to avoid

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 5 Definitions & Acronyms 1 AU 1´´ 1 pc

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 6 Definitions & Acronyms Seeing limited 1´´ 8m diffraction limited

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 7 Definitions & Acronyms

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 8 Goals of Darwin: + Find other Earths Find X-solar Life and

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 9 What is Known: Discovery of Extra-solar Planets since 1995 update : 26 November 2005 Global statistics : 146 planetary systems 170 planets 18 multiple planet systems

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 10 Sun Earth Jupiter Saturn Exo-Planet Type Uranus Neptune

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 11 mass = 1000 radius = 10 density = 1 mass = radius = 0.1 density = 5 mass = 1 radius = 1 density = 1

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 12 Distribution of KNOWN Exoplanets BIASED by METHOD of OBSERVATION

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 13 P = 1 yr Earth: 30 km s -1 Sun: < 10 cm s -1 O ( 100 R Sun ) Observation of STELLAR REFLEX MOTION (Doppler) orbit << R Sun

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 14 P = 1 yr Earth: 30 km s -1 Sun: km s yr Jupiter: O ( m s -1 ) Not Yet Sensitivity  V ~ 10 m s -1 Observation of STELLAR REFLEX MOTION 5.2 AU Distance

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 15 micro-lensing statistics of remote systems distance of O (10 kpc) Besides V rad, other known observational methods planetary transits radius and density of occulting planet direct imaging of structure in young disks presence of planet(s)

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 16 Besides V rad, other known observational methods pulsar timing planet´s mass first detection of Earth-mass planets...

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 17 micro-lensing Y O (hour), not repetitive known observational methods useful for exo-Earths ? planetary transits Y from space (  I/I < ) imaging of disk structure N O (M Jup ), not unique pulsar timing Y few systems, no Life radial velocities N stellar activity of O (m s -1 ) stellar astrometry Y from space O (  arcsec)

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 18 micro-lensing Y O ( hour), not repetitive known observational methods useful for exo-Earths ? planetary transits Y from space (  I/I ~ ) imaging of disk structure N O (M Jup ), not unique pulsar timing Y few systems, no Life radial velocities N stellar activity of O (m s -1 ) stellar astrometry Y from space O (  arcsec) Life

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 19 Life What is ? How originated ?

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 20 Definition of Life... ? (1). Organisms tend to be complex and highly organized. Chemicals found within their bodies are synthesized through metabolic processes into structures that have defined purposes. Cells and their various organelles are examples of such structures. Cells are also the basic functioning unit of life. Cells are often organized into organs to create higher levels of complexity and function. Cellsorganellesorgans (2). Living things have the ability to take energy from their environment and change it from one form to another. This energy is usually used to facilitate their growth and reproduction. We call the process that allows for this facilitation metabolism.metabolism (3). Organisms tend to be homeostatic. In other words, they regulate their bodies and other internal structures to certain normal parameters.homeostatic (4). Living creatures respond to stimuli. Cues in their environment cause them to react through behavior, metabolism, and physiological change. (5). Living things reproduce themselves by making copies of themselves. Reproduction can either be sexual or asexual. Sexual reproduction involves the fusing of haploid genetic material from two individuals. This process creates populations with much greater genetic diversity.sexualasexualhaploidgenetic diversity (6). Organisms tend to grow and develop. Growth involves the conversion of consumed materials into biomass, new individuals, and waste. (7). Life adapts and evolves in step with external changes in the environment through mutation and natural selection. This process acts over relatively long periods of time. mutationnatural selection... etc...

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 21 Origin of Life ?

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 22 What does Life DO ? ! Generates WASTE !

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 23 Life transforms a planet - e.g. its Atmosphere methane oxygen Time (Ga)

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 24 2H 2 O + CO 2 + h  CH 2 O + O 2 + H 2 O produce sugar and OXYGEN oxygenic photosynthesis: Cyano Bacteria `bluegreen algae´

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 25 2H 2 O + CO 2 + h  CH 2 O + O 2 + H 2 O WATER.and. CARBON DIOXIDE.and. OXYGEN Chemical Disequilibrium Atmosphere : simultaneously reducing.and. oxydizing

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 26 IMPLIES BIOACTIVITY

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 27 IMPLIES BIOACTIVITY Spectrum in Thermal Infrared 1.Earth is Hot 2.Atmospheric Lines Opaque Needs Space

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 28 PROBLEM OF CONTRAST Scattered Solar Radiation Planetary Thermal Emission VisibleInfraRed log 10 1O versus

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 29 PROBLEM OF CONTRAST to of central peak intensity in the wings of the PSF PSF = Point Spread Function = Fourier Transform of Modular Transfer Function (MTF)... and in real life not inifinite signal-to-noise

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 30 Solution: Darwin the Mission Nulling Interferometer Destructive Interference provides Needed Contrast Long Baselines provide Needed Resolution

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 31 simplest case: 2 element Bracewell interferometer Nulling Interferometer: Point Sources Rejection Rate:  n  > 10 5 n = 2 for Bracewell to ``null´´ stellar radiation [ e.g. at 10 pc distance and = 10  m] Sun 1.6 Jy* (N = 3.6 mag ) Earth 0.23  Jy (N = 20.7 mag) * 1 Jy = W m -2 Hz -1 star on optical axis  = 0 =

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 32 So - does everything come for free ? This is wonderful ! We gain resolution but loose information and field But for POINT SOURCES OK!

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 33 D Filled aperture D: contains all spatial frequencies up to 1/D => Image of the source

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 34 D B d/2 Interferometer B: picks out 1 spatial frequency 1/B in coherent field of view 1/d Example: = 10  m, B = 200 m, d = 2 m Resolution = 10 milliarcsec Field of view = 1 arcsec

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 35 Equilateral triangle - Darwin architecture: 3.5 m BCS in the centre of triangle -120 deg between telescopes -Variable distance TS to BCS

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 36 Modulation properties

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 37 Spectroscopy

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 38 Beam Combination by Single Mode Waveguide φ B (t) Focusing Optics Single Mode Waveguide Detector ABC φ A (t)φ C (t) Single mode waveguide (SMW) used for modal filtering to improve nulling ratio. Phase relations in SMW of injected on- axis light such that resulting amplitude is zero. Internal modulation by alternating phase shifts between (-120º, 0º, +120º) and (+120º, 0º, -120º) Stellar light can not propagate in fibre core and is rejected into the cladding Ref. O. Wallner et. al “Multi-axial single mode beam combiner”

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 39 Beam Combination

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 40 Signal-to-Noise (S/N) Thermal BG Exo zodi (10) Total noise Leakage Local zodi Detector Transmitted planet signal Equivalent signal of absorption lines SNR integrated over line width

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 41 Science Requirements

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 42 Science Requirements, cntd.

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 43 Assumptions

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 44 Main Observational Requirements Nulling of “on axis” star by 10 5 Baseline accuracy 1 cm Optical Path Difference (OPD) 20 nm Telescope pointing 24 mas Amplitude matching

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 45 Control Modes Fringes Acquired Flyers randomly distributed in a sphere (15 km) Baseline accuracy = 1 cm Array attitude: 0.1 deg. Normal Operation Mode OPD control to 20 nm Pointing control 24 mas Fringe Acquisition Mode Optical Links acquisition Freeze of baselines External OPD rate damping New target / baseline re-arrangement Baseline Control Mode Pointing: 1 arcsec

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 46 Baseline Control Mode mN-FEEP Inertial attitude using star-trackers [ ~1” ] RF range measurement [ 1 cm ] RF goniometry –omni-directional [10 deg ] –narrow angle scanning antennae [ 0.06 deg ]

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 47 Propulsion Fine control:  N - thrust Coarse control:mN - thrust FEEP - Field Emission Electric Propulsion Cold gas

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 48 Micro propulsion

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 49 Preliminary Mission Analysis Mission analysis initiated with ESOC.

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 50 IRSI - Darwin Nuller at L2

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 51 Completed system studies Alcatel (1997 → mid 00) –Seven spacecraft in formation –Launched to L2 by Ariane5 –Mission feasible ! ESA internal studies –“Theta-2” stellar rejection suffices Reducing number of collectors –Dual launch feasible Two Soyuz could be used –Multi Axial Beam Combination New conceptual payload design Wavefront filtering and Beam combination by Single Mode Fibre –Minimum number of collectors (3) 3 collectors 1 beam combiner –Analysis of variability noise –Spectral range Various technology developments

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 52 Current System Assessment Study –Parallel study Alcatel and Astrium –Phase 1(Sep. 05 → Spring 06) Review –Requirements –Payload –Mission Trade-off –Phase 2(Spring 06 → Oct. 06) Preliminary design –Payload –Spacecraft Redundancy philosophy Mission analysis –Phase 3 (Oct. 06 → Spring 07) Design consolidation –Payload –Spacecraft Imaging mode implementation Ground segment Development plan and costing

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 53 Launch Vehicle Dual Soyuz - Cost of a Soyuz / Fregat launch vehicle assumed to be 40 Meuro - Cost of A5 launch vehicle assumed to be 150 Meuro - The cost of Soyuz from Kourou is expected to increase - Extra cost (= fuel and complexity) for rendez-formation not accounted for.

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 54 The challenges –Technological (but no show stoppers!) Nanometer and milli-arcsecond beam control –Optical path length control < 1 nm –Beam intensity matching < 1% Formation flying –4 (or more) spacecraft in close formation –Correction of relative displacement and attitude Cryogenic payload –Passive cooling to 40K of optical elements –Detector operating at 6-8K –Funding (major obstacle!)

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 55 Swedish precursor mission PRISMA Testing Formation Flying Possible Future Big Darwin

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 56 The Future: Planet Imager 20 x 20 pxl image of Earth at 10 pc 0.02  arcsec pxls 6250 km baselines

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 57 Densified pupil supertelescope Possible Architecture: Planet Imager

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 58 or pack down the VLA and fly it in space

Darwin/ Xtrasolar AlbaNova 1 December 2005 p 59 ``cold´´ gas micro propulsion Courtesy Lasse Stenmark, Ångström Lab, Uppsala Thanks !