Mars Sample Receiving Facility and sample containment: Difference between revisions
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</ref> .
The NRC and ESF findings on risks of [[Environmental degradation|environmental disruption]] are accepted by most participants in this debate (with the notable exception of Robert Zubrin<ref name=zubrin>Robert Zubrin "Contamination From Mars: No Threat", [http://www.planetary.org/explore/the-planetary-report/ The Planetary Report] July/Aug. 2000, P.4–5</ref><ref name=zubrin-interview>[http://astronomy.nmsu.edu/cwc/Teaching/SpaceCol/sts497i/Zubrin/transcript.txt transcription of a tele-conference interview with ROBERT ZUBRIN] conducted on March 30, 2001 by the class members of STS497 I, "Space Colonization"; Instructor: Dr. Chris Churchill</ref>). As a result, it is agreed by most researchers that a full and open public debate of the back contamination issues is needed at an international level.<!--(NASA and ESF surveys both say this as well as other sources e.g.) --><ref name=esf2012_PP-debate>{{cite report |title=Mars Sample Return backward contamination - strategic advice |publisher= European Science Foundation |year=2012 |chapter=5: "The Potential for Large-Scale Effects"|url=
Because of these concerns, there are proposals to build a Mars Sample Receiving Facility. This needs to be of a novel design, as it has to function both as a clean room and as a biohazard laboratory
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This page covers the results of studies by NASA and the ESA which examine the need for such a facility, and the risks that need to be mitigated. It also looks into issues of sample containment during return from Mars.
Note that [[Discussion of science value of a Mars sample return |
==Plans to return a sample to Earth before detailed examination==
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The view in the reports from the National Research Council<ref name=nrc2009>
{{cite report |title=Assessment of Planetary Protection Requirements for Mars Sample Return Missions |publisher=National Research Council |year=2009 |chapter=2: "The Potential for Past or Present Habitable Environments on Mars" | url=http://www.nap.edu/openbook.php?record_id=12576&page=22}}</ref> and the European Science Foundation,<ref name=esf2012_PP>[
{{cite report |title=Mars Sample Return: Issues and Recommendations (Planetary Protection Office Summary) |publisher=Planetary Protection Office |year=1997|url=http://planetaryprotection.nasa.gov/summary/msr|quote=''The potential for large-scale effects, either through pathogenesis or [[Environmental degradation|ecological disruption]], is extremely small. Thus, the risks associated with inadvertent introduction of exogenous microbes into the terrestrial environment are judged to be low. However, any assessment of the potential for harmful effects involves many uncertainties, and the risk is not zero. ... The SSB task group strongly endorses NASA’s Exobiological Strategy for Mars Exploration (NASA, 1995). Such an exploration program, while likely to greatly enhance our understanding of Mars and its potential for harboring life, nonetheless is not likely to significantly reduce uncertainty as to whether any particular returned sample might include a viable exogenous biological entity-at least not to the extent that planetary protection measures could be relaxed.''}}</ref> is as follows:
{{quotation|The risks of [[Environmental degradation|environmental disruption]] resulting from the inadvertent contamination of Earth with putative martian microbes are still considered to be low. But since the risk cannot be demonstrated to be zero, due care and caution must be exercised in handling any martian materials returned to Earth.<ref name=nrc2009_4p46>
{{cite report |title=Assessment of Planetary Protection Requirements for Mars Sample Return Missions |publisher=National Research Council |year=2009|url=http://www.nap.edu/openbook.php?record_id=12576&page=46}}</ref>}}
To deal with these issues, these reports recommend construction of a special a Mars Receiving Facility<ref name=MSRtaskgroup>[http://planetaryprotection.nasa.gov/summary/msr Mars Sample Return: Issues and Recommendations (Planetary Protection Office Summary)] Task Group on Issues in Sample Return. National Academies Press, Washington, DC (1997)</ref>.
To deal with these issues, the [[NASA]] Office of Planetary Protection<ref>[http://planetaryprotection.nasa.gov/about NASA Office of Planetary Protection]</ref> recommends construction of a special a Mars Receiving Facility. They recommend that the facility should be operational at least two years prior to launch,<ref name=MSRtaskgroup>[http://planetaryprotection.nasa.gov/summary/msr Mars Sample Return: Issues and Recommendations (Planetary Protection Office Summary)] Task Group on Issues in Sample Return. National Academies Press, Washington, DC (1997)</ref> with various estimates on the time taken to build the facility and bring it to operational readiness. Preliminary studies have warned that it may take as many as 7 to 10 years to get it operational.<ref>{{cite report |title=Assessment of Planetary Protection Requirements for Mars Sample Return Missions |publisher=National Research Council |year=2009 |chapter=7: "Sample-Receiving Facility and Program Oversight" |page=59 |http://www.nap.edu/openbook.php?record_id=12576&page=59 |quote=''It has been estimated that the planning, design, site selection, environmental reviews, approvals, construction, commissioning, and pre-testing of a proposed SRF will occur 7 to 10 years before actual operations begin.17,18,19 In addition, 5 to 6 years will likely be required for refinement and maturation of SRF-associated technologies for safely containing and handling samples to avoid contamination and to further develop and refine biohazard-test protocols. Many of the capabilities and technologies will either be entirely new or will be required to meet the unusual challenges of integration into an overall (end-to-end) Mars sample return program.''}}</ref>▼
The 1997 NRC report recommended that the facility should be operational at least two years prior to launch, as a result of many lapses of containment in the Apollo sample handling procedures <ref>page [https://books.google.co.uk/books?id=SE1qAgAAQBAJ&pg=PA31&lpg=PA31 31] of Board, S.S. and National Research Council, 1997. Mars sample return: issues and recommendations. National Academies Press.</ref> Later sample return studies don't explicitly give this requirement but the rationale still applies.
▲
The official reports stress the need for public debate at the international level due to the ethical issues involved.
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=== ESF update on biohazard risks of MSR ===
The ESF report<ref name=esf2012_PP/> accepts the general conclusions of the NRC report, but went beyond them in several areas. In particular they made a more detailed assessment of size limits of micro-organisms. Before this study, the accepted size limits <ref name=esf2010_3size>[
The 2010 ESF study observed that the Mars sample could contain [[Archaea#Species|uncultivatable archaea]], or [[ultramicrobacteria]]. It might contain Martian [[Nanobacterium|nanobacteria]] 0.1 µm if such exist. A recent concern is that it could contain virus-types and genetransfer agents as small as 0.03 µm in size, especially if Mars life and Earth life share a common ancestor at some point.<ref name=esf2010_LAWKI>[
For the nanobacteria, they accepted recent research that show these 0.1 µm sized cell like objects are mineral deposits, so ruled them out. They discussed [[ultramicrobacteria]] and concluded that the smallest free-living self-replicating microorganisms observed are in the range of 0.12–0.2 µm.
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</ref>
As a result, they recommended a minimum size of 0.01 µm on the basis that this is nearly half the size of the smallest GTAs known and less than a tenth of the size of the smallest currently known free-living self-replicating microorganisms. They recommend that the probability of release of a particle this large should be less than 1 in a million.
In the case where 0.01 µm can't be achieved at a reasonable cost, and in view of the almost negligible risks from GTAs, they give 0.05 µm as a maximum permitted minimum size.
This size was chosen as less than half that of the smallest currently known micro-organisms - so unlikely to contain a free-living microorganism. They recommend that such an increase of the minimum size requirement requires independent review by a panel of experts.<ref>Quotes from the ESF report to assist editors in verifying the paraphrase
{{bq|Unsterilised particles smaller than 0.01 µm would be unlikely to contain any organisms, whether free-living self-replicating (the smallest free-living self-replicating microorganisms observed are in the range of 0.12–0,2 µm, i.e. more than one order of magnitude larger), GTA-type (the smallest GTA observed is 0,03 µm, i.e. three times larger) or virus-type (the smallest GTA observed is 0,017 µm, i.e. almost twice as large). This level should be considered as the bottom line basic requirement when designing the mission systems and operation.}}
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==Risk Mitigation for back contamination==
[[NASA]] has addressed back contamination concerns with a proposal to build a special biohazard containment facility to receive the samples, and with a sample return mission designed to break the chain of contact with Mars for the exterior of the sample container<ref name=esf2010_PP>[
In the European Science Foundation study, these risks were studied in more detail and recommendations made to reduce them to levels considered acceptable.
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The ESF report also points out that biohazard facilities are designed to contain known hazards. The new facility must contain unknown hazards as well. It's a much harder problem to contain unknown hazards, especially with the diversity of life forms now known to be potentially hazardous such as GTAs and ultramicrobacteria (as described above).
Other risks mentioned in these studies, and by the Planetary Protection Office include the possibility of human error, accidents, natural disasters, security breach, actions by terrorist or 'activist' groups or crime, leading to release of the materials, once the samples are on the Earth surface.<ref name=esf2012_PP-crime-etc>{{cite report |title=A Draft Test Protocol for Detecting possible biohazards in martian samples returned to Earth|publisher=NASA |year=2002 |quote="Procedures for handling a breach of the SRF due to different causes (e.g. leak, disaster, security breach etc) should be considered in he development of plans for handling a breach. Concerns about security should also be reconsidered, epecially in view of the potential disruptive activities of any terrorist or 'radical' groups that may be opposed to sample return (page 101) .... The breach could be the result of an accident or a crime - as a result of activity either outside or within containment (page 104)"|url=https://web.archive.org/web/20130215100651/http://planetaryprotection.nasa.gov/file_download/10/MSRDraftTestProtocol.pdf}}</ref>
==== Target probabilities for proposed biohazard facilities ====
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====Risk mitigation for the MSR receiving facilities====
[[File:Mars_sample_return_quote.png|thumb|347 px|size limit for unsterilized particle]]
To deal with the issues of unknown possibly very small forms of life in the sample, the ESF referred to their discussion of size limits (above) and concluded (Recommendation 7) that if possible, the facilities should be designed so that probability should be less than one in a million that a single unsterilised particle of 0.01 µm diameter or greater, if possible, and if that's not possible, that
{{bq|>The
[if this requirement is too stringent then it needs expert review]
The release of a single unsterilised particle larger than 0.05 µm is not acceptable under any circumstance
<ref name=esf2010_LAWKI/>}}
To deal with issues of the novelty of the facilities and of human error, the studies recommended that the receiving facility is operational and the staff trained several years before the Mars samples are brought into Earth's environment. The 2008 report of the IMARS working group report detailed a total of twelve years from initial planning to lander launch.<ref name=imars>[http://mepag.nasa.gov/reports/iMARS_FinalReport.pdf Preliminary Planning for an International Mars Sample Return Mission] Report of the International Mars Architecture for the Return of Samples (iMARS) Working Group, June 1, 2008</ref> Three architectural firms were approached who provided preliminary plans, the FLAD, IDC and LAS plans, the last of these, the LAS has a fully robotic work force to handle the samples.<ref>Jeremy Hsu [http://www.astrobio.net/exclusive/3329/keeping-mars-contained Keeping Mars Contained] Astrobiology Magazine 12/03/09</ref><ref>Beaty DW, Allen CC, Bass DS, Buxbaum KL, Campbell JK, Lindstrom DJ, Miller SL, Papanastassiou DA. [http://www.ncbi.nlm.nih.gov/pubmed/19845446?report=abstract Planning considerations for a Mars Sample Receiving Facility: summary and interpretation of three design studies.] Astrobiology. 2009 Oct;9(8):745-58. doi: 10.1089/ast.2009.0339.</ref><ref>[http://www.nap.edu/openbook.php?record_id=5563&page=31 Mars Sample Return: Issues and Recommendations](1997)] Task Group on Issues in Sample Return, National Research Council (page 31)</ref>
They were not asked to consider human factors and so do not report on ways to mitigate these, except to suggest that care must be taken to minimize human interaction with the sample.<ref name=esf2012_PP-human-factors>{{cite report |title=Mars Sample Return backward contamination - strategic advice |publisher= European Science Foundation |year=2012 |chapter=4.7 Potential verification methods"|url=
===Concerns about incubation period===
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The WHO Leprosy fact sheet<ref>[http://www.who.int/mediacentre/factsheets/fs101/en/ Leprosy Fact Sheet] World Health Organization</ref> gives the [[incubation period]] of [[leprosy]], from first infection to onset of symptoms, as up to 20 years.
In the European Science Foundation report, incubation period is listed as the first of the list of unknowns that make it impossible to use standard models for the effects of a release and its consequences <ref name=esf2012_PP-precautionary>[
====Risk mitigation for incubation period====
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They recommend that potential release scenarios (including undetected release) are clearly defined and investigated, and response strategies developed for them.
They considered it critical that such containment strategies are implemented as soon as possible at the local level, and that they should include rapid detection of anomalies, effective warning procedures, and analysis, resistance and mitigation procedures.<ref name=esf2012_PP-being-prepared>{{cite report |title=Mars Sample Return backward contamination - strategic advice |publisher= European Science Foundation |year=2012 |chapter=5: "The Potential for Large-Scale Effects - 5.4 Being prepared"|url=
====Views of the 2002 COMPLEX study of lessons to be learnt from the Apollo quarantine====
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Other proposals were explored in the 1980s, including direct entry of sample container to Earth's atmosphere, recovery by the space shuttle, recovery to space station, recovery to a dedicated Antaeus space station, and several intermediate proposals.<ref>[http://www.wired.com/wiredscience/2013/02/mars-sample-recovery-quarantine-1985/ Mars Sample Recovery & Quarantine (1985)] DAVID S. F. PORTREE 02.14.13</ref>
Originally through to 2002, the requirement was a simple gas-tight glove box in a biocontainment level 4 facility. <ref>
Board, S.S. and National Research Council, 2002. [https://books.google.co.uk/books?id=vzmcAgAAQBAJ The Quarantine and Certification of Martian Samples[. National Academies Press.
{{quote|"The initial processing of returned martian samples should be restricted to a BSL-4 laboratory in the quarantine facility. A very modest gas-tight glove box (Class III cabinet) in a "clean room" (class 10; however see following g section) will be sufficient for this purpose. " page 51}}</ref>
==See also==
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