Science class should not end in tragedy.... Science class should not end in tragedy....

1. Planetary Protection Considerations for Mars Sample ReturnC. Conley, NASA PPO G. Kminek, ESA PPO4 August, 2010

2. Science class should not end in tragedy.... Science class should not end in tragedy.... Science class should not end in tragedy.... Science class should not end in tragedy.... Science class should not The Basic Rationale for Planetary Protection Precautions (as written by Bart Simpson, Dec. 17, 2000, “Skinner’s Sense of Snow”)

3. Planetary Protection Mission Constraints • Depend on the nature of the mission and on the target planet • Assignment of categories for each specific mission/body is to be determined by the “best multidisciplinary scientific advice” • COSPAR will provide it in case such advice is not available to a nation • Examples of specific measures include: • Reduction of spacecraft biological contamination • Constraints on spacecraft operating procedures • Spacecraft organic inventory and restrictions • Restrictions on the handling of returned samples • Documentation of spacecraft trajectories and spacecraft material archiving

4. Planetary Protection Mission Categories PLANET MISSION MISSION PRIORITIES TYPE CATEGORY A Not of direct interest for understanding the Any I process of chemical evolution. No protection of such planets is warranted (no requirements). B Of significant interest relative to the process of Any II chemical evolution, but only a remote chance that contamination by spacecraft could jeopardize future exploration. C Of significant interest relative to the process of Flyby, Orbiter III chemical evolution and/or the origin of life or for which scientific opinion provides a significant chance of contamination which could jeopardize Lander, Probe IV a future biological experiment. All Any Solar System Body Earth-Return V “unrestricted-” or “restricted Earth-return”

5. Planetary Protection Compliance for Mars Sample Return • Three aspects require PP involvement over mission lifetime • Outbound – protect Mars from Earth organisms • Sample Return – protect Earth from Martian organisms • Life Detection and Biohazard Assessment Protocol: Sample Distribution and Future Missions • Distinguish Earth-originating (round-trip) biota/biomarkers from those of potentially Martian origin • Demonstrate that samples are safe enough to be released from quarantine for distribution to investigators • Requirements on the system to allow for sample distribution may be satisfied via several implementation methods at a range of costs, with significant implications for additional scientific investigations

6. Category III/IV Requirements for Mars Category III. Mars orbiters will not be required to meet orbital lifetime requirements* if they achieve total (surface, mated, and encapsulated) bioburden levels of ≤ 5x105spores . *Defined as 20 years after launch at greater than or equal to 99% probability, and 50 years after launch at greater than or equal to 95% probability. Category IV for Mars is subdivided into IVa, IVb, and IVc: Category IVa. Lander systems not carrying instruments for the investigations of extant martian life are restricted to a biological burden no greater than Vikinglander pre-sterilization levelsa surface biological burden level of ≤ 3x105spores, and an average of ≤ 300 spores per square meter

7. Category III/IV Requirements for Mars (cont.) Category IV for Mars is subdivided into IVa, IVb, and IVc: Category IVb. For lander systems designed to investigate extant martian life, all of the requirements of Category IVa apply, along with the following requirement: · The entire landed system must be sterilized at least to Vikingpost-sterilization biological burden levelsa surface biological burden level of ≤ 30* spores, or to levels of biological burden reduction driven by the nature and sensitivity of the particular life-detection experiments,whichever are more stringent OR · The subsystems which are involved in the acquisition, delivery, and analysis of samples used for life detection must be sterilized to these levels, and a method of preventing recontamination of the sterilized subsystems and the contamination of the material to be analyzed is in place.

8. Category III/IV Requirements for Mars (cont.) Category IV for Mars is subdivided into IVa, IVb, and IVc: Category IVc. For missions which investigate martian special regions (defined later), even if they do not include life detection experiments, all of the requirements of Category IVa apply, along with the following requirement: · Case 1. If the landing site is within the special region, the entire landed system shall be sterilized at least to the Viking post-sterilization biological burden levelsa surface biological burden level of ≤ 30* spores. · Case 2. If the special region is accessed though horizontal or vertical mobility, either the entire landed system shall be sterilized to the Viking post-sterilization biological burden levels a surface biological burden level of ≤ 30* spores OR the subsystems which directly contact the special region shall be sterilized to these levels, and a method of preventing their recontamination prior to accessing the special region shall be provided. If an off-nominal condition (such as a hard landing) would cause ahigh probability (how high is for future PPS consideration) of inadvertent biological contamination of the special region by the spacecraft, the entire landed system must be sterilized to a surface biological burden level of ≤ 30* spores and a total (surface, mated, and encapsulated) bioburden level of ≤ 30 + (2x105)* spores .

9. Sample Return Missions from Mars • Category V. The Earth return mission is classified, “Restricted Earth return.” • Unless specifically exempted, the outbound leg of the mission shall meet Category IVb requirements. This provision is intended to avoid “false positive” indications in a life-detection and hazard-determination protocol, or in the search for life in the sample after it is returned. A “false positive” could prevent distribution of the sample from containment and could lead to unnecessary increased rigor in the requirements for all later Mars missions. • The sample container must be sealed after sample acquisition. A redundant, fail-safe containment with a method for verification of its operation before Earth-return shall be required. The integrity of the flight containment system shall be maintained until the sample is transferred to containment in an appropriate receiving facility.

10. Sample Return Missions from Mars (cont.) • Category V, cont. • The mission and the spacecraft design must provide a method to “break the chain of contact” with Mars. No uncontained hardware that contacted Mars, directly or indirectly, shall be returned to Earth. Isolation of such hardware from the Mars environment shall be provided during sample container loading into the containment system, launch from Mars, and any in-flight transfer operations required by the mission. • Reviews and approval of the continuation of the flight mission shall be required at three stages: 1) prior to launch from Earth; 2) prior to leaving Mars for return to Earth; and 3) prior to commitment to Earth re-entry. • A program of life detection and biohazard testing, or a proven sterilization process, shall be undertaken as an absolute precondition for the controlled distribution of any portion of the sample.

11. SSB Recommendations on Mars Sample Return • Samples returned from Mars should be contained and treated as though potentially hazardous until proven otherwise • If sample containment cannot be verified en route to Earth, the sample and spacecraft should either be sterilized in space or not returned to Earth • Integrity of sample containment should be maintained through reentry and transfer to a receiving facility • Controlled distribution of unsterilized materials should only occur if analyses determine the sample not to contain a biological hazard • Planetary protection measures adopted for the first sample return should not be relaxed for subsequent missions without thorough scientific review and concurrence by an appropriate independent body

12. Avoiding Backward Contamination: Handling Mars Samples • Earth Ground Facilities: • Mobile Retrieval Units (MRU) • Sample Receiving Facility (SRF) • Sample Curation Facility (SCF) • Preliminary examination/ characterization • Subsampling, documentation • Preliminary search for extinct/ extant life • Hazard testing • Rapid retrieval and containment EEVs Quarantine (SRF) Retrieval (MRU) ? Samples Certified Safe • Samples declared safe? • Subsampling • Documentation • Sample distribution • Long-term curation • Cold curation ? Research Laboratories Curation (SCF)

13. Analyzing Returned Samples: The Draft Test Protocol (2002, update planned) Perform appropriate testing for biohazard evaluation and life detection Comply with national regulations and legal constraints: • US National Environmental Protection Act • US Presidential Directive/National Security Council Memorandum #25 Ensure public communication and involvement to the extent necessary for public acceptance* of Mars Sample Return The perceived benefits of Mars sample return must outweigh the costs *and funding!

14. What Does ‘Potentially Hazardous’ Imply? • Hazards must be either destroyed or contained • Contain Mars samples, or sterilize them, to ensure safety of Earth • Must have sufficient confidence on containment • Provisional requirement: 1x10-6 probability of releasing a single 0.2 micron particle of Mars material into the Earth environment (ESF input) • Must have approved protocols for containment and testing • Review and update Draft Test Protocol using best available advice (next) • Requirements on flight system contamination flow back from test protocols • Technical requirements flow from the hazard assessment • – Impact on design and operation • – Impact on flight and ground system (C&C) • – Impact on hardware and software • – Impact on qualification and acceptance margins • Technology development needs are dictated by hazard considerations

15. Probabilistic Constraints Requires: Containment & Sterilization Defined by: Release Probability & Sterility Assurance Level (SAL) Premise: Hazard Policy decision (ESF study): Acceptable risk level Implementation: Flight/ground system, qualification approach, verification and procedures Derived technical requirements: Redundancy & Factors of Safety (FoS) 15

16. One Take on Risk Assessment... “…samples returned from Mars by spacecraft should be contained and treated as though potentially hazardous until proven otherwise…” because “…the potential for large-scale negative effects on Earth’s inhabitants or environments by a returned martian life form appears to be low, but is not demonstrably zero.” ECSS-Q-ST-40C 12th PPWG meeting, recommendation for loss of containment: • Severity level is Catastrophic: potential for severe detrimental environmental effects (conservative assumption for resource allocation, not expected or proven severity level) • Always keep containment/handling visible in the risk log 16