esa technology development activities for fundamental physics space missions b. leone, e. murphy, e....

ESA technology development activities for fundamental

physics space missions

B. Leone, E. Murphy, E. Armandillo

Optoelectronics Section

ESA-ESTECEuropean Space Research and Technology Centre

European Space AgencyNoordwijk, The Netherlands

14 July 2006 ASTROD 2006

Outline

• Presentation of the Optoelectronics Section

• Fundamental Physics Missions at ESA

• Cosmic Vision

• Technology Needs for Future Fundamental Physics Missions

• Technology Development Strategy

• Earth Observation and Planetology

• Current and Planned Activities

• Conclusions


Optoelectronics Section

• Head: Errico Armandillo• Team of experts:

– Detectors• X-rays• UV, VIS, IR• FIR, THz, (sub)mm-wave

– Photonic devices• Fibres and sensors• Optical telecommunication

– Lasers• Lidar• Distance metrology• Frequency standards• Laser-cooled atom interferometry• Laser damage (laboratory)


Terms of Reference

• Optoelectronic device technologies and applications

• Laser technology and components• Photonic integrated optics• Non-linear optics• Superconductor technology• Far-IR heterodyne instrument design and

verification > 1 THz• Detector technology and radiometry for the X-ray,

UV, IR and Far-IR (incoherent and heterodyne) > 1 THz


Our Role within ESA

• Directorate of Technical and Quality Management• Support Directorate within a matrix organisation• Customers:

– Science– Human Spaceflight, Microgravity and Exploration– Earth Observation– Applications

• Telecommunications• Navigation

• Initiate technology development activities in support of programmes and to enable future missions

• Provide technical expertise to projects


Technology R&D

• Initiate and follow up technology development activities up to Technology Readiness Level 5/6– TRL1 - Basic principles observed and reported– TRL2 - Technology concept and/or application formulated– TRL3 - Analytical and experimental critical function and/or

characteristic proof-of-concept– TRL4 - Component and/or breadboard validation in laboratory

environment– TRL5 - Component and/or breadboard validation in relevant

environment– TRL6 - System/subsystem model or prototype demonstration in a

relevant environment (ground or space)– TRL7 - System prototype demonstration in a space environment– TRL8 - Actual system completed and "flight qualified" through test

and demonstration– (ground or space)– TRL9 - Actual system "flight proven" through successful mission

operations


ESA Technology Landscape


Qualification and Reliability

• Laser laboratory facility• Laser diode reliability test envisaged• Low to high power laser diode multimode

emitter/bars/stacks– CW pumping (1-30 Watts) at 808, 9xx nm– QCW pumping (≥ 100 Watts peak power)

• Qualification and reliability aspects– Optical components– Laser diodes


Outline



• Cosmic Vision





• Conclusions


Fundamental Physics Missions at ESA

• Science:– LISA (Laser Interferometer Space Antenna)

• Search for gravitational waves• 50% NASA• Technology R&D not shared

– LISA Pathfinder (LTP)• Technology demonstrator mission• LISA precursor mission

– Cosmic Vision

• Human Spaceflight, Microgravity and Exploration– ACES (Atomic Clock Ensemble in Space) onboard the ISS

• Main goal: technology demonstrator– Test a cold atom clock in space– Test a hydrogen maser in space– Time and frequency comparison with ground clocks

• Three fundamental physics tests:– Gravitational red shift increased accuracy– Search for fine structure constant drift– Search for Lorentz transformation violations


Outline



• Cosmic Vision





• Conclusions


Cosmic Vision 2015-2025

1. What are the Conditions for Planet Formation and the Emergence of Life?

2. How does the Solar System Work?

3. What are the Fundamental Physical Laws of the Universe?

4. How did the Universe Originate and what is it Made of?

[1] Cosmic Vision Brochure – BR247: http://www.esa.int/esapub/br/br247/br247.pdf

[1]


Cosmic Vision 2015-2025

• Explore the limits of contemporary physics– Use stable and weightless environment of space to search

for tiny deviations from the standard model of fundamental interactions

• The gravitational wave Universe– Make a key step toward detecting the gravitational radiation

background generated at the Big Bang– LISA follow-up mission

• Matter under extreme conditions– Probe gravity theory in the very strong field environment of

black holes and other compact objects, and the state of matter at supra-nuclear energies in neutron stars

– X-ray and gamma ray astronomy


Fundamental Physics Explorer Programme

• Do all things fall at the same rate?– Cold-Atom interferometer

• Do all clocks tick at the same rate?– Optical clocks

• Does Newton’s law of gravity hold at very small distances?– Take advantage of the drag-free environment

• Does Einstein’s theory of gravity hold at very large distances?– Pioneer anomaly: potential for optical clocks

• Do space and time have structure?– Fundamental constants– Cold-atom technology and/or ultra-stable clocks

• Does God play dice?– BEC, atom laser, atom interferometer

• Can we find new fundamental particles from space?– Cosmic-ray particle detection


Outline



• Cosmic Vision





• Conclusions


Technology Needs for FPEP

Technology Comment

Cryogenic accelerometers Superconducting test masses and readout (SQUIDs)

Magnetic shielding Extremely low stray fields

Cold-atom source Robustness and reliability, low power, lightweight; atom chips

Low-noise cold-atom source Various elements, e.g. Cs, Rb, H, Mg, Ca, Sr, Ag, Xe, I

Bose-Einstein condensate High level of integration and nanotechnology

Atom traps Tight traps, smaller than the de Broglie wavelength; box-shaped potential wells where atoms can be free-floating

Atom laser Independent cooling and trapping, chip-based atom source, for high brightness

Ultra-stable lasers Low-amplitude and frequency noise, accurate beam-shaping

Ultra-stable microwave source For laser control and frequency combs

Ultra-stable Raman lasers High-frequency stabilisation for narrow atomic transitions


Ultra-High Accuracy Metrology

• Tests fundamental physics theories require ultra-high accuracy metrology of:– Distance– Accelerations– Rotations– Time

• Focus on cold-atom technology:– stabilized lasers: to cool and manipulate atoms– atom interferometry: to measure accelerations, rotations …– (optical) atomic clocks: to measure time and distance

• Miniaturization and space qualification– Micro optics, atom chips– Reliability


Outline



• Cosmic Vision





• Conclusions


A Compelling Strategy

• Given:– One potential fundamental physics mission

– Highly competitive, low funding environment

– Cold-atom technology will benefit from space environment

– Cold-atom technology will benefit fundamental physics

– Large effort needed to bring cold-atom technology in space

• Need to propose cold-atom technology as generic not limited to fundamental physics (navigation, gravimetry)

• Alternatively, find more applications to fundamental physics measurements

• Seek objective commonalities with other customers• For example: Gravimetry

– Earth Observation

– Planetology


Outline



• Cosmic Vision





• Conclusions


Gravimetry

• Studies:– EO: “Enabling Observation Techniques for Future Solid

Earth Missions”– Optoelectronics Section: “Gravity Gradient Sensor

Technology for Planetary Missions”

• Results:– Sensitive gravimeters using very precise atomic clock – Atom Interferometry; gravity gradiometry– Development of Optical Clocks to measure variations of

fundamental constants

[1] “Enabling Observation Techniques for Future Solid Earth Missions”, Science Objectives for Future Geopotential Field Mission, SOLIDEARTH-TN-TUM-001, Issue 6, 1 Nov. 2003. [2] “Enabling Observation Techniques for Future Solid Earth Missions”, Final Report, SolidEarth-TN-ASG-009, Issue 1, 6 May 2004.[3] “Gravity Gradient Senser Technology for future planetary missions”, Final Report, ESA ITT A0/1-3829/01/NL/ND, 13 July 2005.

[1, 2]

[3]


Earth Gravity Missions

• Using satellites to map global gravity field• Measure geopotential second order derivatives• Spherical harmonic expansion• Geoid (equipotential)• Gravity field• Anomalies• Precision (mm, mGal)• Spatial resolution• Temporal resolution• Time span


Applications

• Use satellite and ground data + modelling• Solid Earth• Geophysics• Geodesy• Hydrology• Oceanography• Ice sheets• Glaciers• Sea level• Atmosphere• Lumped sum• Aliasing


Types of Missions

• High Earth orbit (HEO) satellite– Passive laser reflector (LAGEOS)

– Laser tracking from reference ground stations

– Non-gravitational forces removed by design + modelling

• High-Low Satellite-to-satellite tracking (SST)– LEO satellite tracked by GPS type constellation (CHAMP)

– Non-gravitational forces measured by accelerometers

• Low-Low SST– Inter-satellite ranging (GRACE)

– Combined with GPS tracking

– Non-gravitational forces measured by accelerometers

• Satellite gravity gradiometry (SGG)– Gravity field accelerations measured by accelerometers (GOCE)

– Non-gravitational forces measured by (same) accelerometers


HEO mission

• Use high orbit as natural filter (low harmonics)• GPS tracking• Accelerometers• High precision clock (10-16)• Advantages:

– Innovative– Earth sciences– Time keeping– Fundamental physics– Telecommunications

• Drawbacks (as compared to LAGEOS):– Mission life time


GOCE

• GOCE: Gravity field and steady state Ocean Circulation Explorer

• Launch date: 2006• Altitude: 250 km• Orbit: sun synchronous• Main payload: three-axis gradiometers• Observables: diagonal gravity gradient tensor

components, Txx, Tyy, Tzz

• Predicted accuracy: 100 to 6 mE/√Hz• Measurement band: 100 to 5 mHz


Future Needs

• ESA funded Earth Sciences study: “Enabling Observation Techniques for Future Solid Earth Missions” by EADS Astrium

• Low-low SST• Satellite Gravity Gradiometry (SGG)• Observables: diagonal gravity gradient tensor

components, Txx, Tyy, Tzz

• Required accuracy: down to 0.1 mE/√Hz• Measurement band: 100 to 0.1 mHz• (Pointing rate knowledge: 4·10-11 rad s-1/√Hz)• Will current three-axis gradiometer technology be

able to meet these requirements?• Can atom interferometry do it better?


Planets and Moons

• ESA funded GSP study: “Gravity Gradient Sensor Technology for Future Planetary Missions” by University of Twente


Future Needs

• Volume and mass constraints• Size: TBD (assumed 10 cm)• Weight: ~3 kg• Available data: line of sight• Required accuracy: 1 mE/√Hz• Airplane gradiometers (Earth, Mars, Titan) • Technology review:• Superconducting devices• MEMS• Atom interferometry


AI Gradiometer

• Gravity gradiometer Proof-of-Concept (Kasevich et al.)


Planetary Gradiometer

• Back of the envelope concept• Assuming laser and optics miniaturisation• Vacuum chamber size: ~10 cm• Atom cloud size: ~5 mm• Atomic species: Cs or Rb• Baseline 1 m• Weight: few kg?• Could achieve 1 mE/√Hz• 1 m baseline: 10-13g/√Hz• Interrogation time: 10 s

1m

Lasercontrol

electronics

g1

g2

Gravity gradient= (g1-g2)/L

Vacuum chamber with the atom cloud

Optical fibers


Outline



• Cosmic Vision





• Conclusions


What is needed

• Atom Optics– Space qualified stable Source of Cold Atoms

• Compact laser sources for cold atom production– To cool down atoms and control atomic beams

• Ultra-stable Raman Lasers– For coherent matter wave splitting

• Optical frequency synthesizer– Space qualifiable femtosecond comb

• Realisation of a feasible Optical Frequency standard/s for space– Select most suitable option from the choices available

• Realise a completely optical atomic clock– Design and verification


Ongoing Activities

• Atom Optics– Laser-cooled Atom Sensor for Ultra-High-Accuracy

Gravitational Acceleration and Rotation Measurements

• Optical Atomic Clocks– Required linewidth narrower than for optically pumped

microwave atomic clocks– Ultra-narrow linewidth probe lasers: ≤ 1 Hz– Laser-pumped Rubidium gas cell clock (780nm/795nm)

• Solutions implemented @ 780nm:

» External cavity diode laser (ECDL): 100s kHz» Fabry-Perot (FP): 4-6 MHz

– Laser-pumped Caesium bean clock (852nm/894nm)• New activity (894nm) in support of navigation/GALILEO• New activity (894nm) ultra-narrow linewidth for a more generic

application


Planned Activities

• Optical Frequency Synthesizer activities

• Optical Frequency Comb: Critical Elements Pre-Development

– Synthesis of optical frequencies and identification of critical issues for space qualification

– Use for future fundamental physics experiments in space

• Space Compatibility Aspects of a Fibre-Based Frequency Comb


Needed Measurement and Verification

• Narrow band diode laser measurements

– To support the ongoing DFB/FP activities

– To initiate new activities aimed at ultra-narrow linewidth development

– Establish consistent traceable standards in Europe

– Sources of error in linewidth determination

• Heterodyne vs homodyne

• Noise sources

• Line shape dependencies

• Diode laser measurement laboratory

• Comparison with other laboratory


Possible Future Activities

• Laser frequencies for Optical Atomic Clocks – Some possibilities:– Single ion

• Hg+ 282 nm• In+ 237 nm• 171Yb+ (Octopole) 467 nm• 171Yb+ (Quadrupole) 435.5 nm• 88Sr+ 674 nm

– Cold atom• Strontium (Sr) 698 nm• Ytterbium (Yb) 578 nm• Calcium (Ca) 657 nm• Calcium (Ca) 457.5 nm• Silver (Ag) 661.2 nm


Outline



• Cosmic Vision





• Conclusions


Conclusions

• Ongoing/planned work:– Optical Atomic Clocks

– Cold atom source for atom interferometry in space

• Still a lot to be done• Difficult to secure funding when no clear mission is on the

horizon• Adopt strategy of developing generic technologies:

– Time keeping

– Gravimetry for Earth and planets

– Navigation

– etc…

• Comments and suggestions from experts most welcome


谢谢你

Thank you

esa technology development activities for fundamental physics space missions b. leone, e. murphy, e....

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