The science of ExoMars
Andrew Coates
Mullard Space Science Laboratory
University College London
www.ucl.ac.uk/mssl
1. Introduction
2. Mars 3.8 billion years ago & now
3. Water and life
4. ExoMars
With thanks to J.Vago (ESA),
P.Grindrod (Birkbeck) and PanCam
team for some slides
The inner planets
Life now!
Planet (Earth=1) Mercury
Venus
Mars
Radius
0.38
0.95
0.53
Orbit
0.31-0.47
0.72
1.52
Atmosphere
No
90 (CO2)
0.01 (CO2)
Magnetized
Yes
No
No
Life?
No
No
3.8by ago?
Mars 3.8 by ago
Water on surface
Magnetic field
Volcanism
Mars > 4 b years
ago?
D/H ratio shows Mars
had equivalent of a
137m ocean 4.3 billion
years ago
Villanueva et al.,
Science 5 Mar 2015
Mars now
•Extinct volcanoes
•No large-scale
magnetic field, only
remanent regions
•7 mbar, CO2-rich
atmosphere
•Cold, dry
NASA Opportunity
NASA Phoenix, June 2008: are
disappearing pebbles near
North pole subliming water ice?
Evidence for ancient
lake and stream
deposits – conditions
for microbial life
NASA Curiosity
Science, Dec 2013
Flowing/seeping water on Mars now!
Recurring Slope 'Lineae' on Slopes at Hale Crater, Mars …and Garni Crater
NASA/JPL-Caltech/Univ. of Arizona (28 September, Ohja et al., Nature Geoscience)
Solar wind interaction
Magnetized
Unmagnetized
Solar wind pulling away Mars atmosphere
Increased loss during solar activity
MAVEN mission, Science & Geophys. Res. Letters, 5 November (NASA GSFC)
Was there life on Mars?
• Maybe, when Mars was warmer and wetter
• More than 3.8 billion years ago?
• Many now find evidence from meteorite
ALH84001 (announced in 1996) unconvincing
• Must go to Mars to find out!
Requirements for life
•
•
•
•
Liquid water
Essential elements (C, H, N, O, P, S)
Source of heat
Time
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…in the
atmosphere
…
…and
escaping
to space
ESA Mars Express, orbit 28 Jan 04
Water under Mars
surface…
Methane on Mars!
• Mars Express: trace concentrations of
methane (11.5 parts per billion –
Formisano et al 2004)
• Confirms telescope observations
(Mumma et al., 2004, 2009)
• Methane short lived in Mars
atmosphere (hundreds of years)
• Must be a source now (Geothermal
activity? Life?)
• Tantalising results
• Also seen by Curiosity sporadically
(Webster et al., 2013, 2014)
Future missions to Mars
• ESA-Russia
– Trace gas orbiter and EDL demonstrator (2016)
– ExoMars rover (search for life, 2018)
• NASA
– InSight (Interior Exploration using Seismic
Investigations, Geodesy and Heat Transport),
2020?
– Mars Science Lab 2020
• UAE
– Orbiter (2020)
Credit: ESA
2016 Mission Objectives
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TECHNOLOGY OBJECTIVE
‣ Entry, Descent, and Landing (EDL) of a payload on the surface of Mars.
2016
SCIENTIFIC OBJECTIVES
‣ To study Martian atmospheric trace gases and their sources;
‣ To conduct surface environment measurements.
➔
‣
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Data relay services for landed missions until
2022.
Credit: Mamers Valles, MEX/HRSC
Mars Science Laboratory
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• Measurements of methane were conducted over a 20-month period in 2012–2013.
• Webster et al. 2013: No methane detected in Gale Crater within a floor of 1.3 ppbv.
• Webster et al. 2014: Methane background is 0.69 ± 0.25 ppbv with four peaks at 7.2 ± 2.1 ppbv in a 60-sol period.
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Credit: MSL/Curiosity
Methane on Mars
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Adapted from
Atreya et al. 2007
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Credit: Mamers Valles, MEX/HRSC
Spacecraft
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Trace Gas Orbiter
CaSSIS
NOMAD
FREND
ACS
2
0
Schiaparelli
DREAMS
Credit: ESA/Medialab
Trace Gas Orbiter
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NOMAD
High-resolution occultation
andnadirspectrometers
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SO
IR(2.3– 3.8μm)λ/Δλ∼ 10,000
SO
Nadi
r
Nadi
Limb
r
SO
CaSSIS
High-resolution, stereocamera
Mapping ofsources
Landing siteselection
Atmospheric chemistry,aerosols,
surfaceT,
structure
NearIR(0.7– 1.7μm)λ/Δλ∼ 20,000
SO
IR(Fourier,2.5– 25μm)λ/Δλ∼ 4,000(SO)/500(N)
Mid-IR(2.3 – 4.5μm)λ/Δλ∼ 50,000
2
1
S
Limb
IR(2.3– 4.3μm)λ/Δλ∼ 20,000
FREND
Collimatedneutrondetector
R
Atmospheric composition
(CH4 ,O3 ,tracespecies,isotopes)
dust,clouds, P&Tprofiles
UVIS(0.20– 0.65μm)λ/Δλ∼ 250
ACS
Suiteof3high-resolution
spectrometers
A
Limb
SO
Nadi
r
Nadi
r
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Mapping ofsubsurfacewater
and hydratedminerals
Credit: ESA/Medialab, Kees Veenenbos
TGO and MEX Spectral Resolutions
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PFS on MEX
NOMAD and ACS on TGO
CO2
C2 H6
Ethane
20 ppb
Carbon
Dioxide
95%
HCl
Hydrogen Chloride
100 ppb
3000
H2 O
Solar
Water
100 ppm
3005
3010
Wavenumber in Mars Rest Frame (cm–1)
2
2
CH4
Methane
50 ppb
3015
3020
Credit: ESA/Medialab, Kees Veenenbos
Schiaparelli
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‣ A demonstrator of technologies necessary for landing payloads on Mars;
‣ A platform to conduct environmental measurements during the dust storm season.
PAYLOAD
‣ Integrated
mass: 5 kg;
‣ Surface lifetime:
2–4 sols;
‣ Measurements:
• Descent science;
• P, T, wind speed and direction;
• Optical depth;
• Atmospheric charging;
• Descent camera.
Credit: ESA/Medialab
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DREAMS
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Credit: Echus Chasma, MEX/HRSC
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2018 Mission Objectives
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SCIENTIFIC OBJECTIVES
‣ To search for signs of past and present life on Mars;
2018
‣ To investigate the water/subsurface environment as a function of
depth in the shallow subsurface.
TECHNOLOGY OBJECTIVES
‣ Surface mobility with a rover (having several kilometres range);
‣ Access to the subsurface to acquire samples (with a drill, down to 2-m depth);
‣ Sample acquisition, preparation, distribution, and analysis.
‣
To characterise the surface environment.
‣ Russian deep-space communications stations to
work with ESA’s ESTRACK;
‣ Throttleable braking engines for planetary landing.
Credit: Mamers Valles, MEX/HRSC
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ExoMars 2016
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ExoMars 2018
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Mobility + Subsurface Access
Nominal mission :
218 sols
Nominal science :
6 Experiment Cycles +
2 Vertical Surveys
EC length :
Rover mass :
Mobility range :
16–20 sols
300-kg class
Several km
DRILLING TO CENTRAL
DRILL
UPLIFT SAMPLE
DRILL UPLIFT
REACH PISTON IN
CORE
CORE
CUTTING
CENTRAL PISTON IN
DISCHAR
SAMPLE
SAMPLING
(closing shutter)
UPPPER UPPPER
POSITION
DISCHARGE
CUTTING
CORE
GE
DEPTH
POSITION
CORE
FORMING
(closing
FORMING
shutter)
DRILLING TO REACH
SAMPLING DEPTH
1
Credit:
ESA/Medialab
Credit: Argyre Planitia, MEX/HRSC
2-m depth
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ExoMars 2018
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Rover Payload: Looking for interesting locations
PANCAM + ISEM
Multispectral Paroramic 3D Camera (34°FoV)
+ High Resolution Camera (5°FoV), ISEM - IR
Goals are to:
Ø Image landscape,
Ø Characterise materials (geology,
morphology)
Ø Localise zones of interest,
Ø Look for targets
Ø Assist rover navigation,
Ø Survey drilling operations
HRC
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ExoMars 2018
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Rover Payload: Looking for drilling location
WISDOM
Step Frequency Ground Penerating Radar,
0.5 è 3 GHz,
Penetration # 3m, Resolution 5 cm
Goals are to:
Ø Map shallow sub-surface
Ø Provide informations on subsurface
morphology and stratigraphy
Ø Localise drilling location
Traverse soundings
+ last 5 x 5 m pattern
(1 sounding each 10 cm)
1m
ExoMars 2018
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Rover Payload: Drilling and first look on samples and sampling zone
DRILL SYSTEM
Ø 1 rod equipped with drill
tool (+ 1 spare)
Ø 3 extension rods (4 X
0.5m = 2m)
MA_MISS
Vis-NIR (0.4–2.2 μm) miniaturized spectrometer,
20 nm sp. resol. , 0.1 mm diameter target
Goals are to provide:
Ø Vertical distribution of minerals (hydrated mineral
phases, notably water,sulphates, clays...
Ø Mineralogic context of the collected sample
CLUPI
Colour imager, 6.6-μm/px at 10 cm, 15°
FOV, focusing range: 7–50 cm
Ø Investigate geologic, morphological
details and processes recorded in
surface at μm to cm scale.
ExoMars 2018
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Rover Payload: Analytical Laboratory Drawer (ALD)
Core Sample
ALD Door
ALD (Analytical Laboratory Drawer)
Ø Sample Preparation and
Distribution
Ø Instruments (MicrOmega, RLS,
MOMA)
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Analytical Laboratory Drawer
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Pasteur Payload
PanCam
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Geologicalcontext
Rovertraverseplanning
Atmosphericstudies
Wide-anglestereocamerapair
High-resolutioncamera
WAC:35° FOV,HRC:5° FOV
ISEM
Bulkmineralogyofoutcrops
Targetselection
IRspectrometeronmast
λ=1.15– 3.3μm,1° FOV
CLUPI
Close-upimager
Geologicaldepositionenvironment
Microtextureofrocks
Morphologicalbiomarkers
20-μmresolutionat50-cmdistance,focus:20cmto∞
WISDOM
Mappingofsubsurface
stratigraphy
Ground-penetratingradar
3– 5-mpenetration,2-cmresolution
ADRON
Passiveneutrondetector
Drill+Ma_MISS
IRboreholespectrometer
λ=0.4– 2.2μm
Mappingofsubsurfacewater
andhydratedminerals
In-situmineralogyinformation
AnalyticalLaboratoryDrawer
MicrOmega
VIS+IRspectrometer
Mineralogycharacterisation
ofcrushedsamplematerial
Pointingforotherinstruments
λ=0.9– 3.5μm,256x256,20-μm/pixel,500steps
RLS
Ramanspectrometer
Geochemicalcomposition
Detectionoforganicpigments
spectralshiftrange200–3800 cm–1 ,resolution≤ 6 cm–1
MOMA
Broad-rangeorganicmolecules
withhighsensitivity(ppb)
LDMS+Pyr-DevGCMS
Chiralitydetermination
Laserdesorptionextractionandmassspectroscopy
Pyrolisisextractioninthepresenceofderivatisation
agents,coupledwithchiralgaschromatography,
andmassspectroscopy
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What to Search for?
• PRESENT LIFE:
Molecular biosignatures, such as:
…
Sugars
• PAST LIFE:
Phospholipids Amino acids
Nucleobases
Pigments
Images of fossil organisms and their structures;
(morphological evidence)
Organic residues of biological origin;
(chemical, chiral, spectroscopic, and isotopic info)
• DELIVERED ORGANICS:
Credit: Upper Reul Vallis, MEX/HRSC
by meteoritics and
cometary infall
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Rover accommodation on the Landing Platform
Courtesy ExoMars Project
Surface Platform after landing
Courtesy ExoMars Project
ExoMars Rover
Rover launch mass specs
345 kg (310 kg mobile)
Rover Vehicle (incl. 4 ext.
instruments ~ 213 kg*
Science Payload mass: # 27.5 kg
Nominal Mission: # 218 sols
Latitude: 5 S – 25 N
(*) Predicted Mass
Drill System (incl. 2
Instruments) ~ 24 kg*
Analytical Laboratory Drawer
Incl. 3 Instruments
~ 60 kg*
Courtesy ExoMars Project
ExoMarslandingconstraints
Constraint:
Elevation:
Latitude:
Age:
Reason
Parachute
Solarpower&temperature
Science
Where to Search ?
Outcrop
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Penetration of Organic
Destructive Agents
UV radiation
~ 1 mm
Oxidants
~1m
Ionising radiation ~ 1.5 m
ExoMars exobiology strategy:
‣ Identify and study the appropriate type of outcrop;
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Credit: Kees
Veenenbos
Where to Search ?
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Penetration of Organic
Destructive Agents
Subsurface
UV radiation
~ 1 mm
Oxidants
~1m
Ionising radiation ~ 1.5 m
ExoMars exobiology strategy:
‣ Identify and study the appropriate type of outcrop;
‣
Collect samples below the degradation horizon and analyse
them.
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Credit: Kees
Veenenbos
Conclusions
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‣ 2016: ExoMars Trace Gas Orbiter
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Its science will improve our understanding of Mars and of key
atmospheric processes of potential astrobiological relevance.
•
Master landing technologies for future exploration missions.
POCKOCMOC
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POCKOCMOC
‣ 2018: ExoMars Rover and Surface Platform
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A great exobiology mission.
•
The first ever to combine mobility with access to the subsurface.
•
The rover Pasteur payload contains next-generation instruments.
•
The rover will study for the first time:
- Organics and biomarkers for past and present life at depth;
- Vertical characterisation of geochemistry and water.
•
The SP will perform novel environmental measurements.
•
A step closer to Mars Sample Return.
Credit: Mamers Valles, MEX/HRSC
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The eyes of ExoMars:
PanCam
PI: Andrew Coates MSSL-UCL
PM: Craig Leff MSSL-UCL
International team including DLR (D), Space-X
(CH), Joanneum Research (A), Aberystwyth (UK) +
Intl Science Team
PanCam includes:
• Wide Angle Camera (WAC) pair, for multi-spectral stereoscopic panoramic imaging,
using a miniaturised filter wheel
• High Resolution Camera (HRC) for high resolution colour images
• Pancam Interface Unit (PIU) to provide a single electronic interface
• PanCam Optical Bench (OB) to house PanCam and provide planetary and dust
protection
• PanCam Calibration Target (PCT), Fiducial Markers (FidM)
Related hardware: Rover Inspection Mirror (RIM) to provide radiometric and
geometric calibration checks and to observe areas not directly visible by WACs or HRC
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Instrument science overview
The objectives of the ExoMars rover PanCam instrument (see
EICD*) are:
1.
2.
3.
WACs (x2)
HRC
38.3 (edge)
5
1024x1024
1024x1024
Multispectral
RGB
Filter wheel
On chip
11 per ‘eye’
3
627
83
Pixel scale (2m)
1.25mm
0.17 mm
Focus
Fixed
(1.0m-∞)
Mechanical
autofocus
(0.98m-∞)
Provide context information for the rover and its
FoV (°)
environment, including digital elevation models and their
Pixels
proper visualisation.
Filter type
Geologically investigate and map the rover sites
Filter type
including drilling locations.
Filter number
Study the properties of the atmosphere and variable
IFOV (µrad/pixel)
phenomena, including water and dust content of the
atmosphere.
4.
PanCam performance
Locate the landing site and the rover position with
respect to local references, by comparison and data
fusion with data from orbiters
5.
Support rover track planning
6.
Image the acquired sample
The PanCam science team has developed a detailed science
traceability matrix which links the high level goals to instrument
performance (Jaumann et al., 2010).
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* see also Coates et al., Planet Space Sci., 2012,
Griffiths et al., Int. J. Astrob., 2006
•Scientific Payload Requirements Document
EXM-PL-RS-ESA-00001 (Issue 3 Rev.)
•PanCam Specification EXM-PL-PC-SP-MSSL
0005 Issue C
Filterwheel assembly
as used in testing
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18th EXOC, 4
Mar 14,
London
Structural Thermal Model
Delivering Dec 15, after review Nov 9-10!
STM vibration
testing
Reflectance Spectra and Blind Rock Tests
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ExoMars PanCam filter selection
Based on lab tests and AMASE field campaign (Cousins et al., PSS., 2012)
Chamber to simulate Mars surface temperatures
(down to -130°C) for parts of ExoMars PanCam
Inside of chamber with PanCam PIU
circuit board under test
Built by a Worthing company,
commissioned 2010
BVC Sverrefjell Carbonate Outcrop: Panoramic & HRC
data
Calibration Target
WAC Panorama
HRC mosaic
I.Wallace/SciSys
E.Allouis/Astrium
PanCam images from Atacama desert
ESA/ SAFER campaign, 2013
Harris et al., 2015
EXOC, 17
April 2015,
54
Imperial
Summary
• Recent and current Mars missions providing
important results
• Future exploration (ExoMars TGO, rover, MSL 2020)
will follow up with key new data
• ExoMars 2018 important new dimension on Mars: drill
under surface
exploration.esa.int
www.ucl.ac.uk/mssl