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IMPLEMENTATION OF
PLANETARY PROTECTION
REQUIREMENTS FOR THE
RPWI EXPERIMENT
ONBOARD THE JUICE
SPACECRAFT
I. Kolmasova1, O. Santolik1,2, J. Soucek1,
J.-E. Wahlund3, J. Bergmann3
1 Institute of Atmospheric Physics AS CR, Prague, Czech Republic, [email protected]
2
Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic
Institute of Space Physics, Uppsala, Sweden
3 Swedish
International Colloquium and Workshop "Ganymede Lander: scientific goals and experiments”
IKI, Moscow, Russia, 7 March 2013
MOTIVATION
UN Space Treaty of 1967
Article IX
States Parties to the Treaty shall pursue studies
of outer space, including the Moon and other
celestial bodies, and conduct exploration of
them so as to avoid their harmful contamination
and also adverse changes in the environment of
the Earth resulting from the introduction of
extraterrestrial matter, and where necessary,
shall adopt appropriate measures for this
purpose.
International Colloquium and Workshop "Ganymede Lander: scientific goals and experiments”
IKI, Moscow, Russia, 7 March 2013
MOTIVATION
COSPAR (Commitee on Space Research) is
responsible for the formulation of the the
planetary protection rules
any mission to planetary bodies must follow
guidelines for protection of terrestrial and
extraterrestrial biosphere and for the preservation
of the integrity of sites for future exploration
studies
planetary protection and organic contamination
control are important to mission planning,
science, and design of hardware systems
International Colloquium and Workshop "Ganymede Lander: scientific goals and experiments”
IKI, Moscow, Russia, 7 March 2013
SOLAR SYSTEM BODIES
CATEGORIZATION
The solar system bodies are divided in 5 categories
according to the body structure and mission type
(flyby, orbiter, lander).
The categorization is supported by an analysis of
the “remote” potential for contamination of the liquidwater environments that may exist beneath their
surfaces.
A probability of introducing 1 viable terrestrial
organism should be less than 10-4
(for Ganymede)
International Colloquium and Workshop "Ganymede Lander: scientific goals and experiments”
IKI, Moscow, Russia, 7 March 2013
CATEGORY SPECIFIC LISTING
Category I: Flyby, Orbiter, Lander: Undifferentiated,
metamorphosed asteroids
Category II: Flyby, Orbiter, Lander: Venus; Moon (with
organic inventory); Comets; Carbonaceous Chondrite
Asteroids; Jupiter; Saturn; Uranus; Neptune; Ganymede;
Titan; Triton; Pluto/Charon; Ceres; Kuiper-Belt Objects > 1/2
the size of Pluto; Kuiper-Belt Objects < 1/2 the size of Pluto
Category III: Flyby, Orbiters: Mars; Europa; Enceladus
Category IV: Lander Missions: Mars; Europa
Category V: Any Earth-return mission
International Colloquium and Workshop "Ganymede Lander: scientific goals and experiments”
IKI, Moscow, Russia, 7 March 2013
PLANETARY PROTECTION
ACTIVITIES
Probability of impact and survival
factors analysis
Spore Burden analysis
Spores - a special dormant state of some bacteria
Burden - in PP practice, the part of sampled microbes
that survive a heat shock (80°C, 20 min)
Probability of Contamination
Contamination Control
Recontamination Prevention
International Colloquium and Workshop "Ganymede Lander: scientific goals and experiments”
IKI, Moscow, Russia, 7 March 2013
PROBABILITY OF IMPACT
expected maximum probability of accidental impact
on Europa, Titan, Ganymede, Callisto and Enceladus
Flyby and Orbiter spacecraft value: 10-2
Launch vehicle (or part thereof) value: 10-4
the impact analysis includes failure modes, which is
needed for the assessment of transfer of spores to the
surface
International Colloquium and Workshop "Ganymede Lander: scientific goals and experiments”
IKI, Moscow, Russia, 7 March 2013
SURVIVAL FACTOR ANALYSIS
The number of microbes of type X that could survive on an icy
body is based on the initial contamination level [NX0] and
various survival factors:
NXS = NX0 xF1x F2x F3x F4 xF5 xF6 xF7
F1—Total number of cells relative to assayed cells (NX0)
F2—Bioburden reduction survival fraction, when applied
F3—Cruise survival fraction
F4—Radiation survival fraction
F5—Probability of impacting a protected body, including
spacecraft failure modes
F6—Probability that an organism survives impact
F7—Burial survival fraction
NXS should be less than 10-4
International Colloquium and Workshop "Ganymede Lander: scientific goals and experiments”
IKI, Moscow, Russia, 7 March 2013
HOW TO ACHIEVE ACCEPTABLE
CONTAMINATION (Nx0)
Surfaces must tolerate sampling with damp swabs
Areas that cannot be cleaned/assayed must be identified
Surfaces should be smooth, spores like rough surfaces
Components and materials should tolerate temperatures
used for dry heat microbial reduction (110°C to 125°C)
Record keeping (assay results, hardware treatment
history, manipulation with hardware after collection of
assays or microbial reduction process)
All of the above apply also to hardware from outside
sources
International Colloquium and Workshop "Ganymede Lander: scientific goals and experiments”
IKI, Moscow, Russia, 7 March 2013
CONTAMINATION CONTROL
Class 105 (ISO class 8) or better for payload assembly
Cleanliness
Spore density, m -2 Total Microbe
density, m-2
Min Class 10 4 (ISO7) highly controlled
50
500
Class 104 (ISO7) normal control
500
5x103
Class 105 (ISO8) highly controlled
1x103
1x104
Class 105 (ISO8) normal control
1x104
1x105
Uncontrolled manufacturing
1x105
1x106
International Colloquium and Workshop "Ganymede Lander: scientific goals and experiments”
IKI, Moscow, Russia, 7 March 2013
RECONTAMINATION PREVENTION
good cleanroom practices minimize
recontamination
use of remove-before-flight covers
proper storage
transport in clean boxes
International Colloquium and Workshop "Ganymede Lander: scientific goals and experiments”
IKI, Moscow, Russia, 7 March 2013
ECSS-Q-ST-70-55C
Microbial examination
of flight hardware and
cleanrooms
Swab assay 1
for aerobic mesophilic
heat tolerant spores and
vegetative bacteria
International Colloquium and Workshop "Ganymede Lander: scientific goals and experiments”
IKI, Moscow, Russia, 7 March 2013
ECSS-Q-ST-70-55C
Microbial examination
of flight hardware and
cleanrooms
Swab assay 2
for aerobic
mesophilic bacteria
International Colloquium and Workshop "Ganymede Lander: scientific goals and experiments”
IKI, Moscow, Russia, 7 March 2013
RPWI (RADIO & PLASMA WAVES
IINVESTIGATION)
Experiment selected for the JUICE (JUpiter ICy moon
Explorer) spacecraft
RPWI is a highly integrated instrument package that
provides a set of plasma and fields measurements
The key planetary protection requirements for the
ESA JUICE mission are:
1) the probability of impact on Europa should be
evaluated and strictly controlled
2) the chance for contamination of Ganymede’s
putative ocean should be negligible.
International Colloquium and Workshop "Ganymede Lander: scientific goals and experiments”
IKI, Moscow, Russia, 7 March 2013
DESIGN RULES FOR RPWI TO FULFILL
PLANETARY PROTECTION REQUIREMENTS
 consider parts qualifications and manufacturing
processes when selecting components; all
components and materials should survive 125°C when
inactive
 take into account the advantage of vacuum and
radiation conditions after launch
 assess temperature/time profiles of manufacturing
processes, especially for items behind radiation
shielding
 design for tolerance to assays, accountable
surfaces must tolerate sampling with damp swabs or
wipes
International Colloquium and Workshop "Ganymede Lander: scientific goals and experiments”
IKI, Moscow, Russia, 7 March 2013
DESIGN RULES FOR RPWI TO FULFILL
PLANETARY PROTECTION REQUIREMENTS
identify areas that cannot be cleaned/assayed
IPA or ethanol are acceptable for passive
contamination control
assembly and test of flight hardware in ISO 8 clean
room conditions
follow ECSS-Q-ST-70-55C (microbial examination of
flight hardware and cleanrooms) and ECSS-Q-ST-70-58C
(bioburden control of cleanrooms)
transport in clean boxes to prevent recontamination
International Colloquium and Workshop "Ganymede Lander: scientific goals and experiments”
IKI, Moscow, Russia, 7 March 2013
Thank you for
our attention!
Спосибо за
Ваше
внимание!
International Colloquium and Workshop "Ganymede Lander: scientific goals and experiments”
IKI, Moscow, Russia, 7 March 2013