MSR: Breaking the Chain of Contact - MEPAG
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MSR: Breaking the Chain of Contact
Morgan Hendry, BTC Domain Lead
Robert Gershman, PP Program Engineer
Brian Muirhead, Chief Architect
Jet Propulsion Laboratory
California Institute of Technology
April 15, 2020
The decision to implement Mars Sample Return will not be finalized until NASA’s completion of the National Environmental Policy Act (NEPA) process.
This document is being made available for information purposes only.
Jet Propulsion Laboratory, California Institute of Technology.
© 2020. California Institute of Technology. Government sponsorship acknowledged.
Introduction
Mars Sample Return
• The Mars Sample Return (MSR) Program would be the first endeavor since
Apollo to deliver material to Earth from a body of potential biological interest
• NASA’s “Category V restricted return” classification frames the Backward
Planetary Protection requirements that MSR would be required to satisfy
– MSR is working to establish its technical response (and eventually specific
requirements) to the applicable NASA Procedural Requirements (NID 8020.109A):
• “Unless the sample to be returned is subjected to an accepted, approved, sterilization
process, the sample container must be sealed after sample acquisition, and a redundant,
fail-safe containment with a method for verification of its operation before Earth-return
shall be required.”
• “The mission and the spacecraft design shall provide a method to "break the chain of
contact” (BTC) with Mars. No uncontained hardware that contacted Mars, directly or
indirectly, may be returned to Earth unless sterilized..”
– This is consistent with COSPAR Backward Planetary Protection (BPP) guidance
• MSR team recognizes the seriousness of restricted sample return
– Early work building a toolset to “break the chain (BTC) of contact” with Mars
– Supported by robust modeling, testing, and system verification
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This document has been reviewed and determined to not contain export controlled data. Predecisional, for planning and discussion purposes only
General BPP Strategic Approach
Mars Sample Return
• NASA is developing an overall strategic approach for BPP
– NASA Planetary Protection Officer (PPO) initiating an effort with an
international group of scientists to assess the risk of Mars material to
Earth’s biosphere
– MSR Campaign is actively designing systems, verification approaches,
and operational strategies consistent with Break the Chain (BTC) and
Containment Assurance (CA) objectives
• The MSR Campaign would lead this strategic approach through the
Campaign System Engineering Management Office
– The strategic approach will lead to a detailed implementation plan
– Will address roles between NASA and ESA
• National Environmental Policy Act (NEPA) process will be initiated
with inter-agency procedures and all appropriate stakeholders
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This document has been reviewed and determined to not contain export controlled data. Predecisional, for planning and discussion purposes only
BTC/CA Overview
Mars Sample Return
• Break the Chain (BTC) and Containment Assurance (CA) are two of
the many elements that contribute to BPP for MSR, and they are
managed through engineering design, margins, analysis, and test
• Break the Chain (BTC) is an active, surface-to-surface (Mars-to-
Earth) process to satisfy Backward Planetary Protection (BPP) goals
by prohibiting uncontrolled transmission and release of Mars material
of concern into Earth’s biosphere
Break the Chain is how we separate Mars material from Earth’s biosphere
• Containment Assurance (CA) represents engineering steps taken to
ensure that Mars material of concern remains isolated from Earth
Containment Assurance is how we keep Mars material separate from Earth’s biosphere
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This document has been reviewed and determined to not contain export controlled data. Predecisional, for planning and discussion purposes only
BTC/CA Engineering Toolset
Mars Sample Return
• Break the Chain (BTC) would not be accomplished in a single step
– Sequential operations reduce quantity of particles transported to next step
– Engineered BTC features at “pinch points” add extraordinary robustness
• Over five years, the BTC/CA team has explored a broad swath of
technologies and techniques to apply to this challenge
• Guidance from Sterilization Working Group (publication forthcoming)
• Three major tools are used in MSR’s BTC/CA architecture
– Particle Transport Modeling (adhesion, transmission, emission)
– Particle Containment Technologies (seal, encapsulate, isolate, and block)
– Particle Sterilization Techniques
OS Shielding Aseptic Transfer into a Clean Zone Contain EEV
MAS Launch
ERO Return
Capture OS
OS in Orbit
ERO/CCRS
CCRS Ops
Intercept
EEV EDL
to Earth
EEV EEV
Earth
M2020 SRL/MAS Landing Recovery
MARS EARTH
5
This document has been reviewed and determined to not contain export controlled data. Predecisional, for planning and discussion purposes only
Breaking the Chain with Mars (Concept)
Mars Sample Return
Artist’s concept Mars Artist’s concept
Thermal enclosure Barriers enforce
clean zones on OS Reduced Particle Load
and OS Lid
Aseptic Transfer of OS
MAV BODY OS
Minimize Mars material on ERO (SRL) Enforce Clean Zone for EEV (CCRS)
ERO brings material into Earth ERO emits material to Earth or EEV EEV is contaminated before release Containment not assured
ERO ERO ERO ERO
Divert Failure Divert Success Divert Success Divert Success
ERM ERM EEV ERM
EEV
EEV EEV EEV
EEV EEV or COS
1 3
2 4 EEV
Earth 5
This document has been reviewed and determined to not contain export controlled data. Predecisional, for planning and discussion purposes only 6
Assuring Containment of Mars Material
Mars Sample Return
Artist’s concept
Dirty Environment Clean Zone + MMOD Garage HEEET TPS for MMOD resilience
Soft soil preserves science
Localized heating, titanium PCV
shell, and thermal insulation
material limit tube temperature
increase
C-OS
Off-nominal hard surface
Impact
Aseptic transfer uses double attenuation for
walled lid and braze material to hard landings
seal Primary Containment Vessel
(PCV), sterilize its seamline, and Secondary Containment Landing site containment
block Mars material from Vessel provides redundancy,
entering Clean Zone. Passive Earth Entry Vehicle
forms Contained OS (C-OS)
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This document has been reviewed and determined to not contain export controlled data. Predecisional, for planning and discussion purposes only
Early Work Building BTC/CA Capability
Mars Sample Return
Right: Full scale 30 tube 30 tube non-
inductive brazing spherical OS spherical OS
inductive resistive
testbed (2020
brazing ring brazing
demo) and resistive prototype
brazing follow on.
Below: Quarter
scale induction Sterilization Working Group at Johnson & Johnson
testbed, and a Sterility Assurance, June 2019
selection of sealed 200 nm spheres Halo is ~40X optical signature
and separated shells of 200 nm nanoparticles
CLEAN
ZONE
Gridded
SEM plate
Optical and SEM images overlaid and correlated
JPL developing potential nanoparticle and quantum
dot leak tests for V&V (provisional patent) 8
This document has been reviewed and determined to not contain export controlled data. Predecisional, for planning and discussion purposes only
Work Ahead
Mars Sample Return
• Proceeding with the developing of a multi-pronged strategic
approach for BPP implementation across the campaign elements
• Peer review of Break the Chain architecture was held on December
– Review board included members from NASA HQ, ESA, JPL, GSFC,
DARPA, and Dugway Proving Ground
– MSR Campaign is working with this architecture as a baseline
• Transitioning from technology development to flight team
– Full scale brazing demonstrations this year
– Combined C-OS/EEV impact testing late-2021
MSR team recognizes the seriousness of restricted sample return
9
This document has been reviewed and determined to not contain export controlled data. Predecisional, for planning and discussion purposes only
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