fundamental physics at esa o. jennrich esa science directorate
TRANSCRIPT
SpacePart 06 – Beijing – 19 April 2006 Page 2
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)
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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
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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
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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 arcsec (24 μrad) (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
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Planck
Fundamental physics with Planck Nature of Dark Energy and Dark Matter 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)
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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 Thrusters Interferometry
Single spacecraft in Lissajou type orbit around L1 Mission duration 6 months Mission status:
Mission PDR successful in February 2006 Flight hardware delivery Summer 2006 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 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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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
LISA mission concept
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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
LISA mission concept
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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
LISA mission concept
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Cluster of 3 spacecraft in a heliocentric orbit
Trailing the Earth by 20° (50 million kilometers)
Equilateral triangle with 5 million kilometers arm length
Inclined with respect to the ecliptic by 60°
Required by orbital mechanics
LISA mission concept
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LISA Science Goals Merging supermassive black
holes
Merging intermediate-mass/seed black holes
Gravitational captures
Galactic and verification binaries
Cosmological backgrounds and bursts
NASA/CXC/MPE/S. Komossa et al.
K. Thorne (Caltech) NASA, Beyond Einstein
Determine the role of massive
black holes in galaxy evolution
Make precision tests of Einstein’s
Theory of Relativity
Determine the population of ultra-
compact binaries in the Galaxy
Probe the physics of the early
universe
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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 22 May 2006
Letters of Intent due 6 June 2006
Briefing to proposers at ESTEC 12 June 2006
Mission proposals due 18 Sep 2006
WG select 3 S-M & 3 L missions for study phaseOctober 2006
All dates to be confirmed!
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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 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
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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 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.
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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 at a precision level of -1 d/ dt < 110-16 year -1
Crossed comparisons of clocks based on different atomic elements to impose strong constraints on the time drifts of , mee /QCD , and muu /QCD .
Search for violations of
special relativity
Search for anisotropies of the speed of light at the level 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 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 ≥2020