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1 Introduction
Pages 6-20

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From page 6...
... As will become clear later (see "Sterilization by Radiation on Phobos/Deimos Surfaces," in Chapter 2) , the time scale for orbital changes is significantly greater than that of relevance to the planetary protection issues being discussed in this report.
From page 7...
... 8  J.A. Burns, 1992, "Contradictory Clues as to the Origin of the Martian Moons," pp.
From page 8...
... If the moons formed via co-accretion or impact into differentiated Mars, they will probably resemble bulk Mars or differentiated basaltic martian crust.9 Unfortunately, observations of Phobos's 9 S.L. Murchie, P.C.
From page 9...
... Major impacts on Mars may deliver martian materials to Phobos and Deimos.14,15 This process also delivers fragments of Mars -- that is, martian meteorites -- to Earth. The inventory of martian meteorites on Earth consists of about 115 volcanic and plutonic rocks whose chemical and oxygen–isotopic compositions differ from those of other meteorites and suggest their origin from differentiated parent bodies.16 Sedimentary rocks that have been proven to exist on Mars -- for example, from observations conducted by the Mars Global Surveyor spacecraft -- are not among the martian meteorites identified so far.
From page 10...
... All martian meteorites on Earth were ejected from Mars by hypervelocity impact, originating within a nearsurface "spall" zone of inverted pressure gradient, caused by interference between shock waves and rarefactions near the free surface.27 This spall zone comprises accelerated solid rock and has been studied both numerically and analytically.28,29,30,31 Ejection ages indicate that the martian meteorites were delivered to Earth by less than eight discrete impact events between 0.7 and 20 Ma ago.32 Attempts have been made to identify meteorite source craters using spectral matching.33,34 However, such efforts have been hampered by dust that obscures primarily the youngest igneous terrains such as Tharsis.35 The bias of martian meteorites toward young igneous rocks has been investigated through computer simulation by Head et al.36 Their results show that the size of the ejected fragments is affected by target strength; weaker materials, like sedimentary rocks, require larger, and therefore rarer, impact events. This observation may account for the paucity of breccias in the current collection and the absence of sedimentary martian meteorites.
From page 11...
... and shock pressure, which has been calibrated by shock-­ recovery experiments.41 All martian meteorites record shock effects, and their study can be used to estimate shock pressure and post-shock temperature.42 The shock-induced temperature increase is governed by the pressure-volume work achieved by the shock wave, which may be estimated using the linear relation of shock wave and particle v ­ elocity across specific pressure intervals, as described in a 2005 paper by Fritz et al.43 Studies of shock effects in martian meteorites show that they have experienced a range of shock conditions, from weakly shocked nakhlites (5-10 GPa) to more strongly shocked shergottites (20-55 GPa)
From page 12...
... This, however, does not generally preclude the possibility of sampling martian material that may contain signs of biological activity. Chapter 3 returns to the discussion of martian meteorites, because they will prove to be an important factor in determining whether or not samples from the martian moons are designated restricted or unrestricted Earth return.
From page 13...
... MMX has three scientific objectives.55 They are, in priority order: 1. To understand the origin of the martian moons.
From page 14...
... Once a sample has been collected, a robotic arm (not shown) located on the underside of the spacecraft detaches the Sample Canister from ­ the P-Sampler and transfers it to the Sample Return Capsule.
From page 15...
... • Once a core sample is collected, the robotic arm transfers the sample tube to the Earth-return capsule mounted on the side of the spacecraft. Operation of MMX's C-Sampler 1 2 3 Surface imaged to find areas suitable Arm maneuvers to for sampling site to be sampled Descent to Surface of Phobos 4 5 6 Sampling arm C-Sampler collects returns to stowed a core from the position for ascent surface Ascent from Surface of Phobos FIGURE 1.4  The C-Sampler uses a coring device on the end of a robotic arm to acquire a sample.
From page 16...
... Outer Space Treaty (OST) ,59 to which most spacefaring nations are signatory, includes the following language as part of 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." In addition, Article VI of the same treaty specifies the following: "States Parties to the Treaty shall bear international responsibility for national activities in outer space, including the Moon and other celestial bodies, whether such activities are carried on by governmental agencies or by non-governmental entities." Technical aspects of planetary protection policies are developed by individual space agencies and coordinated through the Committee on Space Research (COSPAR)
From page 17...
... Consensus policy recommendations developed by the PPP are then forwarded for discussion and ultimate approval by COSPAR's Bureau and Council prior to becoming official COSPAR policy. The development of the concept of Special Regions on Mars is a good example of how planetary protection policies are developed and evolve as new information becomes available.61 COSPAR planetary protection policy sets requirements for each spacecraft mission and target body depending on the type of encounter it will have (e.g., flyby, orbiter, or lander)
From page 18...
... bodies64 • Unrestricted Earth return -- Venus, Moon, and other TBD bodies The close proximity of Phobos and Deimos to Mars greatly complicates the planetary protection calculations because major impacts on Mars can scatter martian material throughout cismartian space. Some of the ejected martian material will end up on Phobos and Deimos.
From page 19...
... The purpose of the study was to clarify the potential physical processes that can bring about microbial contamination on the surface of martian moons, to obtain a quantitative estimate of the density of microorganisms still surviving in the regolith of the martian moons through several sterilization processes, and to assess microbial contamination probability of samples collected on the surface of the martian moons for future sample return missions from the martian moons. The aforementioned study was presented to this committee and will be referred to as "the JAXA report" in the following sections.70 The results of both the SterLim and the JAXA studies were used to help assess the level of planetary protection measures that need to be implemented for a future sample return mission to Phobos and Deimos to mitigate the risk of release of nonterrestrial life into Earth's environment upon delivery.
From page 20...
... 20 PLANETARY PROTECTION CLASSIFICATION OF SAMPLE RETURN MISSIONS FROM THE MARTIAN MOONS In addition to the reports commissioned above, ESA and JAXA, with NASA also participating (see the P ­ reface) , also requested an independent review of these reports.


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