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Kayser-Threde GmbH, Space Industrial Applications. Paper 78997_0
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1
Kayser-Threde GmbH
w w w . k a y s e r – t h r e d e . c o m
Kayser-Threde GmbH
w w w . k a y s e r – t h r e d e . c o m
w e . c r e a t e . s p a c e .
The ExoMars Sample Handling and Distribution Subsystem
(SPDS)
L. Richter, P. Hofmann, Q. Mühlbauer, R. Paul, D. Redlich (Kayser-Threde
GmbH, Munich, Germany), S.J. Antony (University of Leeds, UK)
Pietro Baglioni and Stephen Durrant, ESA/ESTEC, Noordwijk, The Netherlands
Fabio Musso, Thales Alenia Space, Torino, Italy
ISTVS 7th Americas Regional Conference, 4 - 7 November 2013
Space
Industrial Applications
2
Overview
Recent results from on-going development of Sample Processing
and Distribution Subsystem (SPDS) for ExoMars rover
Programmatic plans for evolutions of SPDS design targeted to
other missions
Development activities on regolith sampling devices
20/12/2013 2 Kayser-Threde Presentation
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20/12/2013 4 Kayser-Threde Presentation
ESA ExoMars 2018 Rover Mission
The ExoMars Rover
carries a drill to collect rock and soil core samples from the Mars
surface and underground (depth down to 2m)
accommodates the Analytical Laboratory Drawer (ALD) with the
‘Pasteur’ Payload, a set of instruments for the search of extant and
extinct life on Mars, and the Sample Preparation and Distribution
System
Credit: ESA
Credit: TAS-I
5
The SPDS receives Mars rock and soil drill core samples from the Rover drill tool and
prepares and presents them to the various analytical instruments.
The SPDS acts as the interface between the drill which is mounted to the outside of the
Rover, and the following ‘Pasteur’ instruments in the Rover Analytical Laboratory Drawer:
Raman Spectrometer (RLS)
MicrOmega Infrared Microscope (MIRU)
Mars Organic Molecule Analyzer (MOMA)
– Gas Chromatograph (GC)
– Laser Desorption Mass Spectrometer (LD-MS)
The sample path and a major part of the SPDS is
located within a sealed enclosure in the Rover/ALD
(Ultra-clean Zone).
20/12/2013 5 Kayser-Threde Presentation
The ExoMars Sample Preparation and Distribution System (SPDS)
Blank Sample Dispenser
Transport
Mechanism
Drill deposits
Mars sample
Crushing Station
Carousel
Dosing Station
Positioner
6
20/12/2013 6 Kayser-Threde Presentation
Core Sample Handling Mechanism (CSHS)
The CSHS consists of
Core Sample Transportation
Mechanism (CSTM)
– input interface for transfer of the
core samples from drill to
Rover/ALD
– opens/closes the door of the
ALD and Ultra-clean Zone
– transports and delivers the
samples to Crushing Station
Blank Sample Dispenser (BSD)
– stores six ‘blank samples’ and
dispenses them into the
Crushing Station when needed
CSHS
ALD/UCZ
front door
Sample
container
CSTM breadboard
BSD design
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20/12/2013 7 Kayser-Threde Presentation
Crushing Station (CS)
Miniature jaw crusher, crushes raw
samples from drill to produce
powder or small grain samples for
further analysis by the Pasteur
instruments
If a sample cannot be
crushed/processed it will be
released by opening the jaws (de-
jamming mechanism) and dumped
into a ‘waste bin’
Design recently enhanced by
addition of a Vibration / Shock
Mechanism (VSM)
Material Input
Material Output
Material Input
Material Output
Dimensions < 130 x 125 x 155 mm
Elegant BB
8
20/12/2013 8 Kayser-Threde Presentation
Powdered Sample Dosing and Distribution System (PSDDS)
Two (redundant) dosing units are
mounted on a rotating arm, can be
positioned either under the Crushing
Station or over the carousel.
The dosing units dispense sample
powder in amounts of 0.1 ml per
dosing step.
The dosing function employs a
revolving wheel with hollow pockets
of defined volume which are filled
with the sample material.
Piezo vibrators are used to ease
sample discharging and cleaning
rotation
Dosing units
Positioner
9
20/12/2013 9 Kayser-Threde Presentation
Powder Sample Handling System (PSHS)
PSHS receives powder samples
from Dosing Station and presents
them to the Pasteur instruments in
– Refillable container (RC)
– Pyrolysis ovens (MOMA GC)
Powder sample surface in RC is
flattened by passing a flat blade
over sample
Samples are positioned with high
accuracy, relative to instrument
viewing ports (MOMA LD-MS,
MIRU)
Sample handling under ultra-clean
conditions in the Ultra-clean Zone
PSHS carousel
Flattening blade
Cleaning blade
Dosing funnel
Camera
Laser sensor
Orientation point
Waste container
MOMA
Camera
RC
PSHS elegant breadboard
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Effect of Mars Gravity
SPDS mechanisms rely on the action of gravity in the flow of granular samples from one mechanism to the next
Combination of testing on parabolic flights and numerical simulations applied to capture and understand effects of reduced gravity
Modelling approach chosen in simulations: DEM (Discrete Element Method)
Latest parabolic flight campaign: December 2012 (by Technical University of Munich): series of different 2D shapes of the PSDDS Dosing Station hoppers at simulated Mars and lunar gravity, with sample holders and powders exposed to Mars atmospheric pressure
Simulation and testing: shown to agree in trends of sample mass flow as function of hopper shape and dimensions, leading to implementation of moderate design changes
20/12/2013 10 Kayser-Threde Presentation
Still from December 2012 TUM /
LRT parabolic flight experiment with
2D hoppers (set of 3 hoppers
of different throat diameters is
visible) (credit: P. Reiss, TUM / LRT)
SPDS DS funnel:
DEM simulation
11
Effect of Mars Gravity
20/12/2013 11 Kayser-Threde Presentation
DEM results on effect of friction
coefficient between hopper wall
material (steel) and grains on
average mass flow rate
DEM results on effect of slit
opening size on average mass
flow rate of particles
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SPDS Test Models and Test Campaigns
Breadboards of all four SPDS mechanisms and an engineering model of the Crushing
Station have been built for test purposes.
Functional tests were performed at ambient laboratory conditions, at low temperature in a
thermal chamber and in a simulated Mars environment
(-50…-60°C, 5…10 mbar CO2) in the Mars Simulation Laboratory of the University of
Aarhus (Denmark).
SPDS end-to-end test (E2E): successfully performed in spring of 2013 involving all SPDS
mechanisms into a combined assembly
12/20/2013 12 Kayser-Threde Presentation
Basalt
sample
Crushing
Station EM (~ 2.8 kg)
13
Laboratory Setup to Test the SPDS End-to-end (E2E) Sample Handling Chain
12/20/2013 13 Kayser-Threde Presentation
SPDS End-to-end (E2E) Test Setup SPDS Mechanisms
Main test goals (initial phase):
“Learn” to operate the
individual mechanisms in
a ‘chain event’
SPDS functions, sample
transfer efficiency
Tests in Mars simulated
environment (T, p, CO2)
Sample
Dispenser
Camera
Tilting
Mechanism
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20/12/2013 14 Kayser-Threde Presentation
Laboratory Test Setup for SPDS End-to-end (E2E) Performance Testing
E2E test setup
equipped with
additional external
sensors for
precise position
measurements
of sample tray /
ovens
powder sample
surface flatness
(laser scan)
15
E2E Test Results
20/12/2013 15 Kayser-Threde Presentation
Scenes from E2E
ambient testing
(January 2013)
16
E2E Test Results
20/12/2013 16 Kayser-Threde Presentation
Close-up of PSDDS sample inlet
hopper with crushed ‘coarse
sand’ having accumulated (outlet
funnel of CS is visible at top)
Crushing progress of gypsum sample in Mars environment;
view is from the top into the CS, showing the gap between
fixed and moving jaws
17
E2E Test Results
20/12/2013 17 Kayser-Threde Presentation
ICY20GLAS ICY10GLAS ICY10GLAS ICY20Mar
s N
igh
t
ICY20
Surface profile after flattening
crushed ‘coarse sand’ sample in
RC in Mars environment (2D
laser sensor profiling)
Dosing of crushed ‘icy’ sample in
Mars environment
18
E2E Test Results 1/2
Testing at both ambient and in simulated Mars environment: very successful
Comprehensive test plan: sample processing and powder delivery tests on all ExoMars drill & SPDS reference materials plus ‘icy’ samples
cores of different rock types in format expected from the ExoMars drill
several Mars regolith (soil-like materials) simulants, some of them doped with Magnesium sulfate and perchlorate salts in concentrations known to exist in the regolith of Mars
ice-containing samples (investigated specifically in Mars environment), produced by freezing a mixture of one of the regolith simulants with 10 and 20 wt-% of water, respectively
CS grain size requirement on fines generated by crushing: fulfilled for the reference materials
Dosing of sample powder: shown to be very repeatable and fulfilling the requirement
Flattening of the sample powder in the RC tray, and its subsequent removal: fulfilling the requirement
PSHS carousel positioning performance: fulfilling the requirement, both at ambient and in Mars environment
20/12/2013 18 Kayser-Threde Presentation
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E2E Test Results 2/2
Successfully processed ice-rich regolith samples (in Mars environment):
Crushing
dosing of powder (with intermediate storage)
Caking of sample powder on jaws of the Crushing Station (CS): observed to be overall
higher than expected, both at ambient and in Mars environment: has led to decision
to implement a hammering mechanism (VSM) into the CS design baseline
In particular in Mars environment, sample powder was observed to adhere to PSDDS
dosing unit hopper internal surfaces to a larger extent than at ambient (probably due to
triboelectric charging), being in line with observations on prior Mars missions with
sample acquisition and handling
primary mitigation measure in design: implement a stronger powder agitation by the
PSDDS piezo actuators by implementing a higher piezo supply voltage
20/12/2013 19 Kayser-Threde Presentation
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Conclusions
Automated sample handling for planetary landing missions:
Always closely associated with sample acquisition
Relevant for in situ as well as sample return missions
Needs to address: reduced gravity, powder adherence (cross contamination),
mechanisms in (self-generated) dusty environment
Kayser-Threde developing ExoMars SPDS (sample handling and distribution S/S)
Recent major achievement: successful end-to-end (E2E) testing of SPDS BB‘s /
EM‘s at ambient and Mars environment
In development for flight in 2018
20/12/2013 20 Kayser-Threde Presentation
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20/12/2013 21 Kayser-Threde Presentation
Acknowledgement
The work reported in this paper was performed by Kayser-Threde (Germany) under
contract to Thales Alenia Space Italia (TAS-I), the ExoMars mission prime, and Selex
Electronics Systems with funding from the European Space Agency.
Several external entities contributed as a project partners.
The authors wish to thank ESA and TAS-I.