Fundamental Physics Activities in the HME Directorate of the European Space Agency

Washington, 24 May 2006 From Quantum to Cosmos 1

Fundamental Physics Activities in the HME Directorate of the

European Space Agency

L. Cacciapuoti and O. MinsterESA/ESTEC


Why Fundamental Physics in Space?• Space is a unique environment

– Infinitely long and unperturbed “free fall” conditions– Long interaction times: improved resolution for the measurement of

weak effects – Quiet environmental conditions – The cosmic particle content in space– Huge free-propagation distances and variations in altitude – Large velocities and velocity variations – Large variations of the gravitational potential

• …but– It is costly– Limited repeatability

• Nevertheless, there are space platforms providing good free-fall conditions and allowing to intervene on experiments … at reasonable costs


HME Microgravity Facilities

Bremen drop-tower

Parabolic flights

Sounding rockets

Space capsules


The ISS and the Columbus Module

EADS Space Transportation


HME Activities in Fundamental Physics• The ACES mission• Future projects in fundamental physics

– Cold and ultracold atoms in space• Space Optical Clocks• Atom Interferometry Sensors for Space Applications• BEC in Space

– Quantum communication in space• Space-QUEST

• Activities in other ESA Directorates for– Initiating studies– Developing key technology and subsystems


The Mission


ACES: Validating Key Instruments in SpaceACES performances Scientific background and recent results

Test of a new generation of space clocks

Cold atoms in micro-gravity Study of cold atom physics in microgravity

Essential for the development of atomic quantum sensors for space applications (optical clocks, atom interferometers, atom lasers)

Test of the space cold atom clock PHARAO

Frequency instability: < 3∙10-16 at 1 dayInaccuracy: ~ 10-16

Short term frequency instability evaluated by direct comparison to SHM.Long term instability and systematic frequency shifts measured by comparison to ultra-stable ground clocks.

Frequency instability: optical clocks surpass PHARAO by one or more orders of magnitude.Inaccuracy: at present, cesium fountain clocks are the most accurate frequency standards.

Test of the space hydrogen

maser SHM

Frequency instability: < 2.1∙10-15 at 1000 s < 1.5∙10-15 at 10000 sMedium term frequency instability evaluated by direct comparison to ultra-stable ground clocks. Long term instability determined by on-board comparison to PHARAO in FCDP.

Performances of state-of-the-art masers

Maser y (1000 s) y (10000 s)

GALILEO 3.2∙10-14 1.0∙10-14

EFOS C 2.0∙10-15 2.0∙10-15


ACES: Validating Key Instruments in SpaceACES performances Scientific background and recent results

Precise and accurate time and frequency transfer

Test of the time and frequency

link MWL

Time transfer stability: < 0.3 ps at 300 s < 7 ps at 1day < 23 ps at 10 days

At present, no time and frequency transfer link has performances comparable with MWL.

Time and frequency

comparisons between ground

clocks

Common view comparisons with an uncertainty level below 1 ps per ISS pass.Non common view comparisons at an uncertainty level of

- 2 ps for 1000 s - 5 ps for 10000 s - 20 ps for 1 day

Existing T&F links

Time stability (1day)

Time accuracy

(1day)

Frequency accuracy

(1day)

GPS-DB 2 ns 3-10 ns 4∙10-14

GPS-CV 1 ns 1-5 ns 2∙10-14

GPS-CP 0.1 ns 1-3 ns 2∙10-15

TWSTFT 0.1-0.2 ns 1 ns 2-4∙10-15

Absolute synchronization of ground clocks

Absolute synchronization of ground clock time scales with an uncertainty of 100 ps.

These performances will allow time and frequency transfer at an unprecedented level of stability and accuracy. The development of such links is mandatory for space experiments based on high accuracy frequency standards.

Contribution to atomic time

scales

Comparison of primary frequency standards with accuracy at the 10-16 level.


Pioneering aspects of the ACES mission• Technology demonstrator for cold

atom based missions• First μg experiments with cold atoms• Validation in space of complex laser

systems • Validation of a new generation of

atomic clocks• Precursor of optical clocks: towards

the 10-18 stability and accuracy regime

• Demonstration of stable and accurate time and frequency transfer

• Long-distance clock-to-clock comparisons

• Contribution to high performance global time scale

Quantum Matter

Quantum Probes

Atomic Clocks

These results will arrive in time to prepare the next generation of atomic quantum sensors for space

from E. Rasel et al.


ESA AO-2004: Ultracold Atoms in Microgravity• Optical Clocks in Space

– Atomic clock ensemble for space applications based on the optical transitions of strontium and ytterbium atoms

– Stability and accuracy of at the 10-17- 10-18 level – Such performances will impose major efforts to improve existing techniques

for time and frequency transfer both space-ground and space-space


ESA AO-2004: Ultracold Atoms in Microgravity• Atom Interferometry Sensors for Space Applications

– Space-based instrument for the measurement of tiny rotations and acceleration and for the detection of faint forces

– Quantum and metrological sciences; direct applications in inertial navigation, Earth observation, geodesy, and geology

Sensitivity to accelerations (108 atoms): Ground 10-10 g/√Hz (expansion time 0.2 s)Space 10-12 g/√Hz (expansion time 3 s)Sensitivity to rotations (108 atoms): Ground: 10-9 rad/√Hz (expansion time 0.025 s)Space: 810-12 rad/√Hz (expansion time 3 s)Earth rotation rate: 7.2 10-5 rad/s

from E. Rasel et al.


ESA AO-2004: Ultracold Atoms in Microgravity• BEC in Space

– BEC facility in microgravity – Based on the technology development of the BEC

“Drop-Tower” experiment (DLR pilot project)– Physics of degenerate Bose gases in g and

applications to atomic quantum sensors based on coherent matter-waves


Science and ApplicationsAtomic Clocks

Fundamental Physics• Standard Model Extension tests

• Universality of the gravitational red-shift

• Time variations of fundamental constants

• Gravitational red-shift • Shapiro time delay and 1/c3 effects

• Gravitational waves detectionApplications• Atomic time scales (TAI)• Time & Frequency metrology• Deep space navigation• Doppler tracking• Synchronization of DSNA• VLBI• Time & Frequency transfer• Gravity mapping• Planetary exploration

Atom Interferometers

Fundamental Physics• Weak Equivalence Principle tests

• Measurement of fundamental constants

• Time variations of fundamental constants

• Measurement of the gravito-magnetic effect

• Tests of the Newton’s law at short distances

• Gravitational waves detection Applications• Inertial navigation• Earth observation and monitoring

• Geology and vulcanology• Gravity and gravity-gradient mapping

• Planetary exploration

Degenerate Quantum Gases

Fundamental Physics• Thermodynamics of the phase transition at ultra-low temperatures

• Collective excitations in the weak trapping regime

• BEC coherence properties in microgravity

• Role of interactions in BEC: dipolar forces and short range interactions

• Dynamics of Bose mixtures in microgravity

Applications• Atomic sources for atom interferometry

• High-resolution interferometric measurements with dilute coherent matter waves


ESA AO-2004: Quantum Communication• Optical communication link:

– Entangled photons transmitter on the ISS (CEPF)

– Optical receivers in one or more ground stations (laser ranging stations)

– Separation of receiving ground stations up to 1600 km

• Fundamental tests of quantum physics:

– Bell’s inequality tests on entangled photons

– Decoherence effects • Quantum communication on global

scale:– QKD between ISS and a ground

station– QK exchange between ground stations

arbitrarily separated via the ISS from A. Zeilinger et al.


ESA AO-2004: Quantum Communication

Quantum communication space terminal based on the OPTEL25 optical terminal designed by CONTRAVES for intersatellite communication


Proposed in the ELIPS 2 Programme• ELIPS 2 programme:

– Discussed during the last Ministerial Council (December 2005)– Subscribed by almost all EU Member States with two new contributors,

Greece and Canada• ISS exploitation programme continuation approved:

– Programme will reach full speed at the launch of the Columbus module (2007-2008 time frame)

• Proposals in the Fundamental Physics consolidation study in ELIPS 2– Cold-atom-based sensors for fundamental physics studies

• Space Optical Clocks• Atom Interferometry Sensors for Space Applications• BEC in Space

– Quantum communication• Space-QUEST

• Upcoming events:– Final programme approved by the European Utilisation Board on the 10-11

May – Formal approval by the HME Programme Board on the 29-30 May

Prototypes


Activities in Other ESA Directorates• Laser systems

– Nd-doped mixed garnet lasers (TRP, E. Murphy, TEC-MME)• Lasers at 935 nm and 942 nm: generation of blue sources for laser cooling

– Ultra-narrow linewidth DFB lasers at 894nm (GSTP, E. Murphy, TEC-MME)• Application in primary frequency standards

– FP laser diode technology development at 779 nm and 894 nm (GSTP, E. Murphy, TEC-MME)

• Manipulation and interrogation of Rb and Cs atoms• Time and frequency metrology

– Optical clocks (GSP, J. De Vicente Olmedo, OPS-GSS)• Study on feasibility and applications of optical clocks as frequency and time

references in ESA deep space stations– Optical frequency synthesizer (GSP, E. Murphy, TEC-MME)

• Study to assess present technology developments and produce new ideas– Critical optical frequency comb technologies (GSTP, E. Murphy, TEC-MME)

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

– Frequency reference dissemination (GSP, E. Murphy, TEC-MME)• Free-space and fiber-based remote comparison


Activities in Other ESA Directorates• Atom interferometry

– Laser cooled atomic sensors for ultra-high accuracy gravitational acceleration and rotation measurements (TRP, B. Leone, TEC-MME)

• High performance space source for laser cooled atoms• Requirements derived from the HYPER mission, but valid for future inertial sensors

based on matter-wave interferometry (gravimeters, gyroscopes,…)• Quantum communication

– Study on quantum communication in space (GSTP, J. Perdigues Armengol and B. Furch, TEC-MMO)

– Accommodation of a quantum communication transceiver in an optical terminal (GSTP, J. Perdigues Armengol and B. Furch, TEC-MMO)

– Experimental evaluation of quantum communication in the framework of the current needs of space systems (GSTP, J. Perdigues Armengol and B. Furch, TEC-MMO)

• Design, development, and experimental evaluation of a proof-of-concept demonstrator

• Successful transmission of entangled photons and QKD over 144 km – Photonic transceiver for secure space communication (GSTP, J. Perdigues

Armengol and B. Furch, TEC-MMO)


Conclusions• The development of projects on cold-atom based systems

and quantum communication techniques will bring about – Outstanding scientific results – Mature, space-proved technology

within a plausible timeframe of 6 to 10 years• Unique opportunity to consolidate this kind of technology and

prepare key instruments for future space missions• Coordination of all potential efforts of ESA, National

Agencies, and scientists on these initiatives


International WorkshopAdvances in Precision Tests and Advances in Precision Tests and Experimental Gravitation in SpaceExperimental Gravitation in Space

GALILEO GALILEI INSTITUTE28-30 September 2006

Firenze, ITALYhttp://www.fi.infn.it/GGI-grav-space/egs_w.html

The workshop is intended to: • Present recent results and advances in precision instruments and tests of

fundamental laws of physics both on ground and in space• Discuss how ground-based experiments can be extended into space missions to

test our understanding of the Universe• Present new ideas and proposals for the next generation of fundamental physics

“explorers” in space• Encourage international collaborations between research institutes on topics of

common interest


List of Topics• Fundamental physics with clocks

– Recent advances on atomic frequency standards and precision measurements;

– Fundamental physics tests with clocks on ground and in space;

– Atomic clock missions in space • Atom interferometry and detection of

weak forces– Inertial sensors– Atom interferometers for gravitational

physics experiments– Tests of gravity at short distances– Measurement of Casimir forces – Ultracold quantum gases

• Precision measurements and fundamental constants– Newtonian gravitational constant G – h/m and fine structure constant– …

• Einstein’s Equivalence Principle tests on ground and in space

– Universality of the free fall – Clock tests of the Local Lorentz

Invariance and Local Position Invariance

– …• Tests of metric theories of gravity

– Measurement of the Lense-Thirring effect

– Measurements of the gravitoelectric perigee shift

– Tests of gravity at long distances– Laser ranging tests– …

• Status on gravitational waves detection

Abstracts submission deadline: 15th July 2006


CommitteesOrganizing Committee:

L. Cacciapuoti (ESTEC, The Netherlands)W. Ertmer (IQ, Germany)C. Salomon (ENS, France)G.M. Tino (University of Firenze, Italy)

Scientific Committee:L. Cacciapuoti (ESTEC, The Netherlands)T. Damour (IHES, France)W. Ertmer (IQ, Germany)P. Gill (NPL, United Kingdom)S. Leon (CNES, France)A. Nobili (University of Pisa, Italy)C. Nary Man (Observatoire Côte d’Azur, France)W. Phillips (NIST, USA)S. Reynaud (LKB, France)C. Salomon (LKB, France)S. Schiller (University of Düsseldorf, Germany)G. M. Tino (University of Firenze, Italy)G. Veneziano (CERN, Switzerland)

Documents

Fundamental Physics Activities in the HME Directorate of the European Space Agency