Fundamental Physics at ESA
J. Clavel
ESA
Science Directorate
Overview
 Two dedicated missions in the Science Directorate
 LISA Pathfinder
 LISA
 Missions with aspects of FP in the Science Directorate
 Gaia
 Planck
 Mission concepts under assessment
 Fundamental Physics Explorer
 Minor contributions to nationally led missions
 Microscope (CNES)
 Missions in other Directorates but supported through Science
Directorate
 ACES (led by Human Spaceflight)
From Quarks to Cosmos – Airlie - 22 May 2006
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ACES
From Quarks to Cosmos – Airlie - 22 May 2006
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ACES mission
 ESA mission conducted by Human Spaceflight
 To be installed on the ISS (Columbus module)
 Payload
 Cs fountain clock (PHARAO)
 Hydrogen maser (SHM)
 Microwave link
 Mission goals:
 Test of a new generation of space clocks
 Precise and accurate time and frequency transfer
 Fundamental physics tests
 Status: payload development
 Launch: 2010
From Quarks to Cosmos – Airlie - 22 May 2006
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Microscope
 CNES-led mission to investigate the equivalence
principle
 Target sensitivity 10-15
 Room-temperature experiment
 Measurement principle:
 compare the effect of gravity on two masses of
different material
 2 differential accelerometers in free-fall (PtRh/PtRh
and Ti/PtRh)
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Microscope
 ESA contributes μN thrusters (FEEP)
 ONERA: inertial sensor development
 Development status
 Satellite PDR February 2006
 Launch
 May 2010
From Quarks to Cosmos – Airlie - 22 May 2006
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Planck
 Measuring the CMB with unprecedented accuracy
 T/T = 2 × 10-6 (about 10 times better than WMAP)
 Angular resolution 5 arcmin (about 3 times better than WMAP)
 Wide frequency coverage (30–857 GHz).
 Payload
 Low Frequency Instrument (LFI)
• Intensity and polarization at 33 GHz, 44 GHz and 70 GHz
• Cryogenic detectors (20 K)
 High Frequency Instrument (HFI)
• Bolometric measurements (intensity and polarisation) at 6 frequencies at
100 – 857 GHz
• Detector temperature 0.1 K
From Quarks to Cosmos – Airlie - 22 May 2006
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Planck
 Fundamental physics with Planck
 Nature of Dark Energy and Dark Matter
 Tests of & constraints on inflation
 Baryogenesis
 String theory
 Status
 Payload flight models under test, delivery to ESA
July/August 2006
 Launch
 Foreseen Q1 2008 (joint launch with Herschel on
Ariane 5)
From Quarks to Cosmos – Airlie - 22 May 2006
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Gaia – Taking a census of the galaxy
 Astrometric mission to measure positions, distances, and
space motions of stars in our galaxy
 About a 109 stars up to magnitude 20
 median parallax errors: 7 μas at 10 mag; 20-25 μas at 15
mag; 200–300 μas at 20 mag
 Distance accuracy: between 1% and 10%
 Velocity accuracy: between 0.5 km/s and 10 km/s
 Status
 Implementation phase
 Launch
 December 2011
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Gaia science objectives





Galaxy origin and formation;
Physics of stars and their evolution;
Galactic dynamics and distance scale;
Solar System census;
Large-scale detection of all classes of astrophysical objects
including brown dwarfs, white dwarfs, and planetary systems;
 Fundamental physics
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Fundamental Physics with Gaia
 Determine PPN parameters
 |1-| < 5×10-7
 |1-|< 3×10-4
 Solar quadrupol moment J2 to 10-7–10-8
 Variability of the gravitational constant
tG/G to 10-12–10-13 yr-1
 Constraints on gravitational wave energy at frequencies between
10-12 Hz and 4×10-9 Hz
 Constraints on M and  from quasar microlensing
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LISA PF
 Precursor to LISA
 Demonstrating critical technologies for LISA
 Drag-free
 Micro-Newton Thrusters
 Interferometry
 Single spacecraft in Lissajous type orbit around L1
 Mission duration 6 months
 Mission status:
 Mission PDR successful in February 2006
 Flight hardware delivery Summer 2007
 Launch in Q4 2009
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LISA PF
 Payload
 Payload consists of a European contribution
•
•
•
•
Two gravitational reference sensors
Interferometric measurement system
Drag free control system
μN thruster
 US contribution
• Disturbance reduction system – descoped!
• Drag free control system and μN thruster
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LISA PF Inertial Sensor
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LISA PF IMS
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LISA
 Mission to detect and observe gravitational waves and their
sources
 Joint ESA/NASA mission
 Europe: Payload, Payload integration, propulsion module
 NASA: Payload, Payload integration, Spacecraft, launcher,
operations
 Science operations will be conducted jointly
 Technological challenges
 Interferometric measurements to picometer accuracy
 Drag-free technology
 Low frequency stability
 Definition/Development: 2010 after completion of LISA PF
 Launch date ~2017 (present planning assumption)
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LISA mission concept
 Cluster of 3 spacecraft in a heliocentric orbit
 Spacecraft shield the test masses from external forces (solar
wind, radiation pressure)
 Allows measurement of amplitude and polarisation of GW
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LISA mission concept
 Cluster of 3 spacecraft in a heliocentric orbit
 Trailing the Earth by 20° (50 million kilometers)
 Reducing the influence of the Earth-Moon system on the
orbits
 Keeping the communication requirements (relatively)
standard
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LISA mission concept
 Cluster of 3 spacecraft in a heliocentric orbit
 Trailing the Earth by 20° (50 million kilometers)
 Equilateral triangle with 5 million kilometers arm length
 Results in easily measurable pathlength variations
 Orbit is still stable enough to allow for mission duration larger
than 5 years
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LISA Science Goals
 Determine the role of massive
black holes in galaxy evolution
 Make precision tests of Einstein’s
Theory of Relativity
 Determine the population of ultracompact binaries in the Galaxy
 Probe the physics of the early
universe
 Merging supermassive black
holes
 Merging intermediatemass/seed black holes
 Gravitational captures
 Galactic and verification
binaries
 Cosmological backgrounds
and bursts
NASA/CXC/MPE/S. Komossa et al.
K. Thorne (Caltech)
From Quarks to Cosmos – Airlie - 22 May 2006
NASA, Beyond Einstein
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Call for CV Mission Proposals (1)
 First of 3 Calls (TBC) for implementation of CV2015-2025
 Available budget for a ~2016 launch: ~320 M€ (1 effective budget year)
 The Call will nevertheless be fully open:
 No a priori size restriction, but clear cost guidelines
 Mission could be
• a small/medium size S/M mission (≤320 M€ cost to ESA)
• a large ESA alone L mission (≤650 M€ cost to ESA)
 Selection of L mission will serve for long term technological development
for mission launch in  2020
 Up to 2 S/M (depending on size) + 1 L missions will eventually be
implemented
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Schedule of Call for proposals
 Call for mission proposals released
10 June 2006
 Letters of Intent due
30 June 2006
 Briefing to proposers at ESTEC
 Mission proposals due
 WG select 3 S-M & 3 L missions for study phase
July 2006
December 2006
February 2007
All dates to be confirmed!
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LISA
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Backup slides
ACES Mission Objectives I
ACES Mission
Objectives
ACES 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 day
Inaccuracy:
~ 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 s
Medium 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
From Quarks to Cosmos – Airlie - 22 May 2006
sy (1000 s)
sy (10000 s)
GALILEO
3.2∙10-14
1.0∙10-14
EFOS C
2.0∙10-15
2.0∙10-15
Maser
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ACES Mission Objectives II
ACES Mission
Objectives
ACES performances
Scientific background and recent results
Precise and accurate time and frequency transfer
Test of the time
and frequency
link MWL
Time and
frequency
comparisons
between ground
clocks
Time transfer stability: < 0.3 ps at 300 s
< 7 ps at 1day
< 23 ps at 10 days
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
Absolute
synchronization
of ground clocks
Absolute synchronization of ground clock
time scales with an uncertainty of 100 ps.
Contribution to
atomic time
scales
Comparison of primary frequency standards
with accuracy at the 10-16 level.
From Quarks to Cosmos – Airlie - 22 May 2006
At present, no time and frequency transfer link
has performances comparable with MWL.
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
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.
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ACES Mission Objectives III
ACES Mission
Objectives
ACES performances
Scientific background and recent results
Fundamental physics tests
Measurement of
the gravitational
red shift
Absolute measurement of the gravitational
red-shift at an uncertainty level < 50 ∙ 10-6
after 300 s and < 2 ∙ 10-6 after 10 days.
Space-to-ground clock comparison at the 10-16
level, will yield a factor 30 improvement on
previous measurements (GPA experiment).
Search for time
drifts of
fundamental
constants
Time variations of the fine structure constant
a at a precision level of
a -1  da / dt < 110-16 year -1
Crossed comparisons of clocks based on
different atomic elements to impose strong
constraints on the time drifts of a, me /QCD , and
mu /QCD .
Search for
violations of
special relativity
Search for anisotropies of the speed of light
at the level d c / c ~ 10-10.
Measurements relying on the time stability
of SHM, PHARAO, MWL, and ground clocks
over one ISS pass.
ACES results will improve previous
measurements (GPS-based measurements, GPA
experiment, measurements based on the
Mössbauer effect) by at least one order of
magnitude.
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S-M Missions schedule
Assessment phases
Jan 2007 – Dec 2008
 Internal assessment phase in 2007
 Competitive industrial assessment in 2008
 Emphasis on payload, cost and risks
Presentation to Working Groups for prioritisation
April 2009
SSAC recommendation for selection
April 2009
Selection of 2 missions
May 2009
Preparation & release of ITT
Jun-Dec 2009
Start of industrial Definition Phase
Jan 2010
SPC approval for development phase 1 mission
Jun 2011
Launch
From Quarks to Cosmos – Airlie - 22 May 2006
Mid-end 2016
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L Missions schedule
Study and Technology development phase
Jan 2007 – Jun 2010
WG review and prioritisation
Sep 2010
SSAC recommendation for 1 L mission
Oct 2010
Start Technology consolidation Phase
Apr 2011
Start Definition Phase
Apr 2013
Start Implementation phase
Apr 2015
L Mission Launch
From Quarks to Cosmos – Airlie - 22 May 2006
≥2020
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