Findings of the Mars

Forward Lunar Objectives

Science Analysis Group

By the MEPAG Mars Forward Lunar Objectives Science Analysis Group

David Beaty, (Mars Program Office, JPL/Caltech), Jennifer L. Heldmann
(NASA Ames Research Center / SETI Institute), Lewis Peach (USRA), Noel
Hinners (Consultant), Ben Clark (Lockheed Martin), Robert Easter (Jet
Propulsion Laboratory), Robert Braun (Georgia Tech), Richard Mattingly
(Jet Propulsion Laboratory), Chip Shearer (University of New Mexico)

September 16, 2006

# 

[Recommended bibliographic citation:]{.underline}

MEPAG MFLO SAG (2006). Draft Findings of the Mars Forward Lunar
Objectives Science Analysis Group, Unpublished white paper, 22 p, posted
October, 2006 by the Mars Exploration Program Analysis Group (MEPAG) at
<http://mepag.jpl.nasa.gov/reports/index.html>.

or

Beaty, D.W.; Heldmann, J.L.; Peach, L.; Hinners, N.; Clark, B.; Easter,
R.; Braun, R.; Mattingly, R.; Shearer, C.; (2006). Draft Findings of the
Mars Forward Lunar Objectives Science Analysis Group, Unpublished white
paper, 22 p, posted October, 2006 by the Mars Exploration Program
Analysis Group (MEPAG) at http://mepag.jpl.nasa.gov/reports/index.html.

[Correspondence authors:]{.underline}

Comments are welcome, and should be directed to David W. Beaty
(<David.Beaty@jpl.nasa.gov>, 818-354-7968), Jennifer L. Heldmann
(jheldmann@mail.arc.nasa.gov, 650-604-5530), or, Lewis Peach
(peach@hq.usra.edu, 410-730-2656). Document Review reference number:
CL#06-3374.

[]{.mark}

**Executive Summary**

[]{.mark}

The Mars Exploration Program Analysis Group (MEPAG) has completed a
preliminary analysis of the June, 2006 draft list of possible lunar
objectives from the perspective of its relevance to preparation for
human missions to Mars. MEPAG has reached eight preliminary findings.

1)  The issues associated with flying crewed missions to the Moon and to
    Mars are similar in some ways and quite different in others. Thus,
    only some of the developments/lessons learned associated with human
    exploration of the Moon will be directly relevant to Mars and a
    Mars-dedicated program will be necessary to resolve remaining
    issues.

2)  Preparing for crewed missions to Mars will involve a four-component
    program consisting of Mars robotic precursors, preparation work at
    the Moon, work in LEO, and work done on the Earth. These four
    components are currently unevenly and incompletely planned.

3)  The presently-considered lunar program has some relevance to Mars,
    and this relevance could be increased with revisions to some of the
    lunar objectives. Proposed rephrasing is described in the appendix
    to this report.

4)  Carrying out the lunar investigations under consideration will not
    lead to a reduction in the requirements in MEPAG Goal IV (Prepare
    for Human Exploration). Goal IV considers measurements and
    technology demonstrations that can [only]{.underline} be done at
    Mars.

5)  There is an uncertain but potentially important relationship between
    lunar ISRU and martian ISRU that needs further study to enhance the
    potential of Mars ISRU.

6)  The primary scientific linkages between Mars and the Moon were
    recently (2004) evaluated by MEPAG; those linkages are reaffirmed.

7)  The draft list of lunar objectives is not missing objectives of
    importance to preparation for Mars.

8)  The "Preparation for Mars" theme provides a compelling focus for the
    lunar program. The utility can be maximized by using "Preparation
    for Mars" as a prioritization criterion for lunar objectives.

**1. Introduction and Background** (from Jeff Volosin, NASA-HQ)

**1.1 Purpose**

In late 2005, the NASA Administrator stated that in 2006, NASA would
initiate a process to define a compelling story to address two
questions:  \"Why are we returning to the Moon?\" and \"What are we
going to do when we get there?\"  The Exploration Systems Mission
Directorate (ESMD) initiated an effort, with participation from the
Space Operations Mission Directorate (SOMD) and the Science Mission
Directorate (SMD), to define and implement a process to address these
questions.  The initial stage of this process focused on the need to
facilitate broad community involvement in addressing these questions,
identifying key objectives for the lunar exploration program and thus
contribute to the development of a more inclusive and comprehensive
Global Exploration Strategy.  Inputs were to be solicited from academia,
international space agencies, and private sector organizations.  By
collecting and analyzing these data, NASA would then be in a better
position to define the role that the United States should play in lunar
exploration as well as begin to develop an understanding of potential
opportunities for broad cooperation and collaboration in the exploration
of space.

 

2.  **NASA Exploration Workshop**

To initiate this process, NASA held an Exploration Strategy Workshop in
Washington D.C. in April of 2006.  Over 180 engineers, scientists,
entrepreneurs, and other exploration experts from the international
community attended this Workshop and provided NASA with some initial
thoughts on the answers to the two questions posed above, that were
captured in the form of Themes and Objectives:

1)  Why are we returning to the Moon? - Captured as lunar \"themes\"
    that provide a high-level compelling rationale for a return to the
    Moon.  Example: *Use the Moon to prepare for future human and
    robotic missions to Mars and other destinations.*

2)  What are we going to do when we get there?  - Captured as lunar
    \"objectives\" that were defined as a set of closely associated
    specific tasks that when completely accomplished, would result in a
    significant accomplishment in at least one of the theme areas
    defined above.  Example: *Characterize impact cratering flux over
    the Moon\'s geologic history.*

    2.  **Additional Inputs**

In addition to this Workshop, NASA solicited independent recommendations
for lunar objectives from the public through a Request For Information
(RFI) that was open through early May 2006.

3.  **Synthesis and Vetting Process**

  The result of these two activities led to the identification of 85
proposed lunar themes and over 800 proposed lunar objectives.  Since
these submissions were provided by many different individuals, NASA next
initiated an internal Synthesis Team activity to remove duplication and
combine similar proposals.  The result of this synthesis effort was the
identification of six unique lunar themes and 85 lunar objectives.  In
an effort to ensure that this resulting set of themes and objectives was
thorough and complete, NASA next initiated a series of vetting processes
utilizing existing specific organizations that represented academic,
international space agency and private sector scientific and exploration
interests.  These organizations included:

\- 13 international space agencies

\- All 10 NASA Centers

\- The Lunar Exploration Analysis Group (LEAG)

\- The Mars Exploration Program Analysis Group (MEPAG)

\- The Lunar Architecture Team (LAT)

\- The Lunar Commerce Roundtable

\- The NewSpace 2006 Conference

\- The NASA Advisory Council, Space Science Subcommittees

\- The Next Generation Exploration Conference at Ames Research Center

\- The Space Enterprise Council of the U.S. Chamber of Commerce

**1.5 Resultant Product**

The result of this process was the identification of an additional 100
lunar objectives and additional information that could be used to
support the six themes identified earlier.  As a result of the extensive
engagement of the community in this assessment, more than 1,000
individuals had provided inputs to the process.

> []{.mark}

**2. Basis for Assessment**

[]{.mark}

**2.1 MEPAG Goal IV Mars Human Precursor Study**

[]{.mark}

A recent study was conducted by the MEPAG Mars Human Precursor Science
Steering Group (MHP SSG) (Beaty et al., 2005) to analyze the priorities
for precursor investigations, measurements, and
technology/infrastructure demonstrations that would have a significant
effect on the cost and risk of the first human mission to Mars. The
purpose was to determine, in priority order, the ways in which the risk
of a human mission to the martian surface can be reduced by means of
robotic flight missions to Mars.

The scope of the MHP SSG study was to analyze the investigations of Mars
by precursor robotic missions for the purpose of reducing mission
risk/cost and increasing performance of a human mission to Mars.
However, in order for a preparatory program to be complete, the
following kinds of precursor investigations also need to be considered:

-   Investigations that can be carried out at the Moon.

-   Investigations that can be carried out in Earth-based laboratories
    or in Mars-analog field environments on Earth (other than on
    returned martian samples).

-   Investigations of the space environment of relevance to a human
    mission other than those specifically at Mars.

The MHP SSG considered ONLY robotic precursor missions to Mars. However,
the current MFLO SAG study builds upon the work of the MHP SSG in terms
of identifying the major risk/cost to a human Mars mission and also
opportunities to cost-effectively increase performance. The MFLO study
differs from the MHP SSG study in that the MHP SSG study considered
robotic precursor missions to Mars as preparation for a human Mars
mission whereas this MFLO SAG study considers robotic precursor missions
to the Moon in preparation for a human Mars mission.

> []{.mark}

**2.2 Purpose and Scope of MFLO Review**

ESMD has recently prepared a draft set of themes and objectives for
lunar exploration that have been synthesized from several activities,
including the NASA Exploration Strategy Workshop and a Request for
Information. NASA's formal statement of its strategic goal linking Mars
and the Moon is to "establish a lunar return program having the maximum
possible utility for later missions to Mars and other destinations".
This topic is critically important and will influence the architecture
for upcoming lunar exploration.

The purpose of the MFLO review is to evaluate the draft lunar planning
from the perspective of eventual application to Mars. MEPAG was thus
invited by NASA Headquarters to review the synthesis report and address
the following questions:

1.  Have any themes or objectives been overlooked?

2.  Are any themes or objectives redundant, hence ought to be combined?

3.  Are any themes or objectives overstated or unachievable?

4.  Are the themes and objectives clearly and unambiguously stated?

[]{.mark}

**2.3 MFLO Analysis Process**

The MFLO analysis included the following steps:

• An analysis of the primary ways in which human missions to the Moon
and Mars are similar and different. This leads to more specificity in
understanding which aspects of the lunar program are relevant to
preparation for Mars.

• An evaluation of the priority of the draft lunar objectives from a
Mars perspective. The list was prioritized in two ways: Relevance to
\"Prepare for Mars" (referring primarily to preparation for human Mars
missions) and relevance to "Understanding Mars" (referring primarily to
scientific knowledge regarding Mars as a planetary system).

• As needed, revising the lunar objective statements to make them
appropriately Mars-relevant.

The team further considered:

• Does the conduct of the lunar program in any way allow us to reduce
the requirements of MEPAG Goal IV (Preparation for Human Exploration)?

• What is the best way to maintain a Mars focus within the lunar
planning structure?

**2.4 MEPAG Validation Process**

[]{.mark}

The MFLO assessment was conducted on a time scale of two weeks by a
small \'tiger-team\' that had extensive involvement in the development
of the recent analysis of MEPAG Goal IV. Because of the timing, it has
not yet been possible to carry out MEPAG's normal vetting process, so
this should be considered an interim assessment.

The MFLO study will be vetted with the Mars community, however, through
the standard MEPAG procedures. The initial findings of the MFLO SAG will
be presented to the community at the upcoming MEPAG meeting in
Washington, D.C. (January 2007). Community members will then have the
opportunity to comment on the MFLO findings. These comments will be
evaluated and incorporated as appropriate by the MFLO study team. Once
the findings reach a state of consensus then the white paper will be
published as an official MEPAG document.

[]{.mark}

**3. Comparison of Human Missions to the Moon and Mars**

[]{.mark}

In order to analyze the ways in which the various aspects of the lunar
exploration program might be beneficial to Mars, it is helpful first to
compare and contrast the essential aspects of missions to the two
destinations.

[]{.mark}

**3.1 Primary similarities between crewed missions to the Moon and
Mars**

The primary similarities that provide a basis for designing lunar
systems with maximum utility for eventual application to Mars human
missions are discussed here. Such utility is two-fold: 1) physical
systems designs, the basic elements of which can be applied with
customization to Mars and 2) relevant operational experience.

A.  The most obvious similarity is the mutual need for high reliability
    life support systems as neither environment has the requisite water,
    atmosphere or food to sustain a crew on the surface. Thus for both
    destinations life-support must be provided for the full mission
    duration which includes both round-trip transit and surface
    stay-time. For the Moon it is feasible and practical, relatively
    speaking, to use a "brute force" system of supply and resupply with
    attendant disposal of used resources. In theory such an approach is
    also possible for Mars. However, the cost of delivering mass to and
    from Mars is so much greater, and the mission opportunities, which
    are limited by orbital mechanics, are so infrequent, that it may be
    mission limiting if alternatives cannot be developed. Such
    alternatives include closed-loop or nearly-closed-loop life support
    systems and, eventually, ISRU (in situ resource utilization). Both
    of these techniques, while not essential, would enhance
    long-duration lunar outpost missions. It is doubtful that a Mars
    mission architecture which was dependent upon these technologies
    would ever be undertaken without having first demonstrated "proof of
    concept" for these techniques in a prior application (not
    necessarily on the Moon - some could be done on Earth and the
    International Space Station (ISS)).

B.  Sustaining the health of crews is essential for survival and for
    effectively attaining mission goals. Operating for prolonged periods
    in low-gravity (\~ 1/6 Earth gravity for the Moon and \~ 1/3 Earth
    gravity for Mars), exposure to cosmic and solar radiation and
    exposure to pervasive dust are environmental conditions common to
    both the Moon and Mars. They differ only in degree. The
    long-duration implications of lunar gravity are unknown, as are the
    implications of martian gravity. Human exploration of the Moon will
    provide the first good, long-duration, data point between
    micro-gravity (ISS) and 1 g (Earth) which will go a long way towards
    understanding the implications of Mars gravity and for developing
    any needed counter-measures to mitigate serious physiological
    de-conditioning issues and help assure human health for long
    duration missions to Mars. Radiation is another matter of serious
    concern for the human exploration of space. Techniques developed for
    constructing radiation shielding on the Moon, using native
    (regolith) materials, the attendant computer models and improved
    understanding of the biological effect of high-Z cosmic rays can be
    directly transferred to Mars missions. The effects of lunar vs.
    martian dust is more problematic as both the chemical and physical
    characteristics of the dust are grossly different in the two
    environments. However, lessons learned in ameliorating both
    mechanical and physiological effects of lunar dust will produce a
    cadre of engineers steeped in the discipline of developing seals,
    filters, cleansing techniques, and overall less-susceptible
    mechanical and electrical designs. Similarly, physiologists must
    understand the implications of the inevitable crew inhalation of
    micron and sub-micron dust particles, of irritation of eyes and
    mucous membranes and of possible chemical reactivity (probably more
    serious on Mars with its known highly oxidizing dust).

C.  Potential health hazards go beyond those which may be induced by
    gravity, radiation and dust. Judged by some to be the most
    challenging for a Mars mission are the psychological factors induced
    by a two-to-three-year isolation from home, with no quick abort
    possible and, relative to lunar missions, a greater likelihood of
    medical emergencies. While no simulation or lunar mission can impose
    the reality of "no early return", long-duration lunar missions can
    aid in developing work/recreation/social interaction schemes
    designed to maintain a healthy mental outlook. And even in the lunar
    case, there could well arise medical emergencies which cannot be
    resolved with a three to four day abort to Earth. It, like launch
    vehicle losses, is simply a question of time.

D.  Surface infrastructure and support requirements such as EVA
    (extravehicular activity) space suits, mobility systems and habitats
    are common elements of all Moon and Mars sortie and outpost
    missions. Again, designs will differ in detail yet the commonality
    of fundamental requirements for ease and flexibility of crew motion,
    reliable and repairable mobility systems and for highly functional
    yet homey, personalized habitats argues for high potential
    relevance.

E.  Both Moon and Mars exploration programs need development of greater
    launch capacity and larger power systems than currently exist. While
    solar cells and fuel cells can in theory supply some of the needs,
    the development of nuclear surface power for lunar applications will
    be directly useful on Mars, especially if ISRU becomes practical; in
    fact, nuclear power may be enabling for ISRU, which in turn, is also
    likely enabling to long-term, sustainable human exploration.

F.  Concerning scientific exploration per se, the basic techniques of
    geological and geophysical field research are well known and common
    to all planetary body explorations. They are fundamentally variants
    of what has been done on Earth and as was demonstrated on Apollo.
    New, however, is the potential for a significantly enhanced
    integrated robotic/human exploration. Long geophysical traverses,
    remote sampling and robotic assistants to do the drudge work and go
    into potentially hazardous locations are but a few examples of what
    can and ought to be done. Such an integrated approach will be
    valuable in lunar exploration but likely more so on Mars given the
    much higher cost per unit time of astronaut work.

A common theme runs through "primary similarities": to best prepare for
eventual Mars human exploration, a constant awareness of and
accommodation of the requirements for Mars must become part of the
everyday thinking of lunar exploration. Even if some Mars "requirements"
add incremental cost, the long-term payoff may well justify that
investment. It is also likely that such investment will result in a more
effective and productive lunar exploration.

**3.2 Primary differences between crewed missions to the Moon and Mars**

A.  Both Mars and the Moon have very dry, rocky, dusty terrain and both
    have a lower gravity field than Earth. But the martian gravity level
    at its surface is more than twice that of the Moon, so that the
    relatively heavy portable life support systems (PLSS) built into
    spacesuits that were used in the Apollo missions would be far too
    heavy for use on Mars.

B.  Mars also has a sensible atmosphere, which profoundly affects the
    engineering challenges of safe entry, descent and landing (EDL) as
    well as operations on the surface. The EDL phase of landed missions
    for Mars requires an aeroentry heat shield with thermal protection
    of the aft-body. All Mars missions to date have also used a large
    disk-gap band parachute deployed at supersonic velocities to further
    reduce the entry velocity. Retrorockets have been used for terminal
    propulsion, augmented by crushable legs or air bags. In many areas
    of Mars, the population of angular rocks is very high. On Mars, high
    near-surface winds must be accounted for in this terminal descent
    system.

C.  The presence of an atmosphere and further distance from the Sun
    moderates temperature swings on Mars. On the Moon, peak daytime
    temperature of soil can reach +120 deg C or more, i.e., higher than
    the *boiling* point of H~2~O. On Mars, excursions above the
    *freezing* point of H~2~O are brief, restricted in both location and
    season. The day-night temperature swings on the Moon are about 300
    deg C in amplitude, whereas on Mars diurnal cycles vary by 60 to 100
    deg C.

D.  Lunar dust sticks to cloth because of the Velcro-like action of
    glass blebs on the surfaces of grains created by relentless
    bombardment by hypervelocity micrometeoroids. Small meteoroids
    encountering Mars are ablated and slowed in the martian atmosphere
    before reaching the surface. On the other hand, the martian dust is
    a far finer grain size than lunar regolith, presumably because of
    being created by a combination of physical and chemical weathering.
    Dust devils are common in many places on Mars, but absent on the
    Moon. Methods of filtration and cleaning to mitigate dust may be
    somewhat different, but could also have important similarities.
    Rovers on Mars have gotten bogged in low bearing-strength soils
    which so far have not been encountered on the Moon.

E.  The Moon is much closer to Earth in distance and in travel time
    (although there is not a proportionate reduction in 'propulsion
    energy requirements' because lunar missions do not benefit from
    aeroentry, or atmospheric drag, which reduces descent delta-velocity
    requirements for Mars missions, whereas lunar missions require
    all-propulsive maneuvers). Aborting from a lunar mission for reasons
    of crew safety is quite feasible, as Apollo 13 demonstrated, but
    aborting a Mars mission is almost out of the question after the
    first week or so in space, with the exception of forgoing a landing
    for a long, slow, free return abort. Communications latency to the
    Moon requires about three seconds in an optimum case, and is not
    significantly more difficult than delays using geosynchronous
    satellite links. For Mars, roundtrip light travel time is up to
    forty minutes, and dips to eight minutes for only a short portion of
    mission time. Teleoperation of rovers on Mars has proven to be a
    distinctly different operation mode from the "joysticking" that is
    possible for rovers on the Moon. For this reason, it is often
    thought that martian astronauts must have far greater operational
    autonomy than lunar astronauts have ever been afforded. The long
    time in space and inaccessibility for resupply for a Mars mission
    will likely demand closed-loop regenerative processing of life
    support commodities such as air and water. Such has not been found
    necessary for Moon, shuttle and space station operations because of
    their more limited duration missions and reasonably frequent ability
    to resupply from Earth.

F.  In situ resource utilization (ISRU) at Mars is far different because
    of the availability of a key ingredient, carbon dioxide, in the
    atmosphere. Also, water is present in almost all martian soils and
    ice deposits are likely within a few meters of the surface at many
    mid and high latitudes on Mars. Neither CO~2~ nor H~2~O are present
    at these high levels on the Moon, except possibly in permanently
    shadowed polar traps. Extraction of lunar oxygen will be from
    regolith minerals, whereas on Mars it can be from the atmosphere or
    soil water. The specific engineering systems will be different, but
    gaining experience in operability of systems requiring access and
    processing of surface materials at the Moon could demonstrate
    generic feasibility (or difficulty) of such systems for Mars (see
    Section 4.4 for a detailed discussion of the special case of ISRU).

G.  Another key difference is the requirement for planetary protection,
    which is serious for forward contamination of Mars but with even
    more serious safeguards needed to assure protection against back
    contamination. Although the Apollo program had some measures in
    place to achieve these, it was quickly decided that they were not
    necessary and will not be required in future missions. Because the
    Moon is sterile, it can provide a useful testing ground, to assess
    the effectiveness of forward contamination preventative measures.
    should the lunar program be willing to develop its habitats and
    spacesuits with this as an engineering requirement.

**3.3 Preparation for Mars Exploration**

Preparing to send humans to Mars within acceptable risk standards will
require a variety of precursor development work. We can organize this
development work into four distinct portions according to venue:
activities done at Mars, at the Moon, in Earth orbit, and on the Earth.
As pointed out by Hinners et al. (2005), there is a well-defined
progression in cost across this sequence---doing things at Mars is much
more expensive than doing them on the Earth. This derives from the
obvious but all-to-frequently unstated fact that as one moves away from
Earth, the amount of data and the flexibility of experiment design,
testing and re-test progressively decrease and the cost escalates
dramatically. We cannot justify acquiring information at Mars if
information of acceptable quality and utility can be acquired less
expensively on Earth. As an example, experimenting with and developing a
closed-loop space-qualified life support system is easier and cheaper to
do on Earth followed by first flight demonstration on ISS.

-   The NRC's Safe on Mars report (Space Studies Board, 2002), and the
    MEPAG Mars Human Precursor analysis (Beaty et al., 2005 and Hinners
    et al., 2005) are recent analyses of the measurements and flight
    demonstrations required [at Mars]{.underline} to reduce the risk of
    the first Mars human mission to acceptable levels. In the case of
    the MEPAG analyses, it was assumed that any work that could be done
    at a lower-cost venue (Moon, LEO, Earth) would not be done at Mars,
    and was explicitly excluded from consideration. The NRC and MEPAG
    studies therefore have the form of a 'must-do' list for the Mars
    part of the problem.

-   The present planning exercise regarding the Moon has the form of a
    large 'could-do' list, which as of this writing had not been
    distilled to its essential requirements. These various possible
    objectives are driven by a variety of reasons, only one of which is
    preparation for Mars. Thus, the standard for evaluating the degree
    of importance to Mars human preparation is different than for a
    dedicated Mars mission. We are not asking whether the same objective
    (from the perspective of Mars) can be accomplished less expensively
    in LEO or on Earth. It is a given that we will be going to the Moon,
    and it is up to us to derive as much benefit from the opportunity as
    possible.

-   An analysis of the portion of the Mars preparation activity that
    could optimally be carried out in low Earth orbit or on Earth has
    not yet been produced.

It is becoming increasingly clear that a plan describing the full
spectrum of activity required to prepare for the conduct of safe human
missions to Mars is essential. Even though such a plan would need to be
carried out over an extended period of time, and the work would
certainly be sponsored by a variety of funding entities (on an
international basis), without this we don't have a clear means of
knowing how the pieces all fit together, how they relate to each other,
and whether there are gaps that are not being worked at all. In
particular, this would help us to understand the importance of the
various R&D activities taking place on Earth at Mars analog field sites,
in laboratories, in engineering test facilities, and by means of
computer simulations.

[]{.mark}

**4. Analysis of Priority of Draft Lunar Objectives to Mars**

[]{.mark}

**4.1 Prioritization Scale**

[]{.mark}

In assessing the relevance of the lunar objectives to Mars exploration
and science, the MFLO SAG felt that a simple binary response was
inadequate and that it is more useful to indicate the **degree** of
relevance to Mars; Therefore, a prioritization scale, consisting of the
following definitions, was developed and used to rate the degrees of
relevancy.

[]{.mark}

[Essential Precursor Requirement]{.underline} =\> An activity that must
be performed on the Moon, as a precondition to human exploration of
Mars, which is considered enabling and therefore is a firm requirement
that must be met, and one that might only be achieved through the lunar
exploration program.

[High Relevance]{.underline} =\> An activity that, given the lunar
program, could be performed on the Moon as a precursor to Mars
exploration, which is considered of sufficient value and priority that
it warrants a marginal investment to assure maximum relevance to Mars
(i.e., there is a high correspondence between the activity at the Moon
and the fidelity of a representative capability that is needed at Mars,
and this is seen as a cost effective, and timely means to achieve this
goal).

[Medium Relevance]{.underline} =\> An activity that, while it could be
performed on the Moon, might be more effectively accomplished by other
means - Earth analogs, space station, robotics precursors, etc. (i.e.,
there is a less compelling rationale that these activities need to be
demonstrated on the Moon, and/or, there may be more efficient (lower
costs) or more relevant means (higher fidelity) to achieve these goals).

[Low Relevance]{.underline} =\> An activity that is of low priority for
the \'Mars Human Precursor-Lunar Program\' (MHP-LP) that would be better
demonstrated by other means. (i.e., demonstrating this on the Moon is of
sufficiently low value that this should not be a part of the MHP-LP).

[(No score, or \'X\')]{.underline} =\> n/a - An activity, which while
possibly serving other needs, is not seen as relevant to the MHP-LP.

[]{.mark}

**4.2 General Relevance of Lunar Program to Preparation for Mars**

[]{.mark}

The MEPAG MFLO SAG examined the draft lunar objectives from two
perspectives including 1) relevance to preparation for Mars human
missions and 2) relevance to better understanding Mars scientifically.
MFLO study results indicate that a significant fraction of the lunar
objectives have [some]{.underline} (variable) degree of relevance to
Mars. The qualifier is significant in that no objective was considered
absolutely essential (i.e., absolutely required before one could conduct
Mars human exploration). In other words, one could proceed today with
preparation for Mars human exploration without an intervening lunar
program. Notably, no Mars-relevant objectives were deemed missing from
the lunar objectives. Neither of these observations negates the
potential utility of lunar exploration in preparing for Mars; the lunar
exploration program offers many opportunities to better prepare for
Mars. In that spirit, the MFLO SAG examined the individual objectives
and suggested modifications that could improve the relevance to Mars.
Additionally, as mentioned in the previous section, a priority ranking
was assigned to each objective, rather than simply checking the box of
relevant or non-relevant. The lunar program has not yet incorporated
this prioritization approach; we recommend that this be done as the
total set of lunar objectives is further refined.

3.  **Relationship of Lunar Program to MEPAG Goal IV: Prepare for Human
    Exploration**

MEPAG has conducted an analysis of the robotic science measurements and
engineering/technology developments that could accomplish significant
risk-reduction for Mars human exploration (MEPAG, 2006). The Goal IV
study pertaining to "Prepare for Human Exploration" had two major
objectives A: Obtain knowledge of Mars sufficient to design and
implement a human mission with acceptable cost, risk and performance and
B: Conduct risk and/or cost reduction technology and infrastructure
demonstrations in transit to, at, or on the surface of Mars.

When Goal IV was developed, it was assumed that any work that could be
done somewhere other than Mars (e.g. on Earth, in Earth orbit, on the
ISS, or on the Moon) would be done in these alternative locations.
Nevertheless, as a sanity check, the MFLO SAG examined Goal IV to
re-assess whether any of its objectives could instead be accomplished on
the Moon. The finding is "No", reinforcing that some objectives must be
carried out at or on Mars well before one can conduct a human
exploration mission. Our reassessment had an ancillary positive benefit
of helping determine where selected lunar objectives could be made more
relevant to Mars preparation. Our proposed re-writes of selected lunar
objectives reflects that perspective.

**4.4 A Special Case: ISRU Moon/Mars Linkages**

Elements of ISRU (in situ resource utilization) constitute many of the
objectives of the lunar exploration program. It is recognized as a
potentially valuable technique to significantly reduce the mass carried
to the Moon and thus reduce the cost of lunar exploration and to be
relevant to Mars. Indeed, similar objectives have been stated for future
Mars human exploration and MEPAG Goal IV addressed the Mars-unique
aspects of ISRU. Given the greater cost of carrying mass to Mars, its
application at Mars takes on greater importance; some believe that ISRU
may be, along with other mass-saving approaches, enabling of a human
Mars mission. That said, for both the Moon and Mars, the potential of
ISRU is subject to major uncertainties regarding the nature of the
resources present, their accessibility, future supply/demand
relationships, and technical/economic factors involved in extraction,
production, storage and utilization processes. Developing and proving
out certain basic ISRU capabilities on the Moon has direct relevance to
its application to Mars. However, there are significant, non-trivial
differences. On the Moon, regolith silicates and ilmenite are a known
widely available resource. They each require extensive energy to extract
oxygen and have unique processing requirements. The possibility that
exploitable hydrogen exists in permanently shadowed polar regions gives
hope that an easily extractable source of fuel will be available. For
Mars, atmospheric CO~2~ and hydrogen (most likely as water) are widely
present and likely obviate the need to use silicates.

The ultimate value of lunar ISRU experience to future Mars application
depends to a significant degree on resolution of many details concerning
both the Moon and Mars. This uncertain but potentially important
relationship between use of lunar ISRU and martian ISRU needs further
study to enhance the potential of Mars ISRU.

> **4.5 Science Linkages between the Moon and Mars**

Lunar planetary science investigations are not required to prepare for
human exploration of Mars. However, one of NASA's goals pertaining to
the lunar program is to ensure "maximum possible utility for later
missions to Mars". Based on this goal, there are important scientific
concepts that could be developed on the Moon that will provide valuable
insights into understanding Mars as a planet. The scientific linkages
between the Moon and Mars were most recently examined in the MEPAG white
paper *"Findings of the Moon→Mars Science Linkage Science Steering
Group"* (Shearer et al., 2004). This analysis group reviewed this
document and concluded that the basic scientific linkages were still
valid.

The Moon*→*Mars Science Linkage Steering Group (2004) and the
Exploration Strategy Workshop (2006) identified fundamental science
themes that are relevant to understanding both the Moon and Mars. The
science themes are cross-referenced in this discussion.

A.  *Early Planetary Evolution and Planetary Structure*: The Moon has
    been and will continue to be the scientific foundation for our
    understanding of the early evolution of the terrestrial planets. The
    detailed geologic record of these early events has long since
    vanished from the Earth and has been at least partially erased from
    Mars. The Moon contains the remnants of one of the basic mechanisms
    of early planetary differentiation: magma ocean. These remnants are
    in the form of a primary planetary crust and subsequent crustal
    additions that were products of melting of magma-ocean products in
    the lunar mantle. Clearly, the differences in size and formation
    between the Moon and Mars have affected the style of differentiation
    and early magmatism. However, the Moon provides a valuable and
    nearly complete end-member model for a style of planetary
    differentiation and early planetary magmatism. Understanding the
    internal structure and mantle dynamics of a second planetary body
    (the Earth being the first) will provide invaluable insights into
    the dynamical history of the martian mantle and core, the history of
    the martian magnetic field, and the evolution and structure of
    primary planetary crusts. The Moon presents the best opportunity to
    geochemically characterize early fundamental processes of a
    planetary body of substantial size, including the early
    differentiation into component parts, the production of an early
    crust, and the genesis of basalts from various mantle depths. Much
    of the first billion years of planetary geochemical evolution is not
    available on Earth. In this regard the Moon and Earth represent
    end-member bodies in that the Moon reveals early geochemical
    processes, whereas the Earth is a continually active planet. Mars
    probably represents an intermediate case.

B.  *Evolution of Planetary Surfaces*: Some surface modification
    processes will be very similar for the Moon and Mars, and others
    will differ due to the presence of fluid erosion and chemical
    weathering on Mars. The Moon retains the history of the early impact
    environment of the inner solar system, at the time when life may
    have first arisen on the Earth and perhaps Mars. Understanding the
    character of the impact history of the inner solar system from
    4.5-3.8 Ga is fundamental to reconstructing the planetary surface
    environments under which life arose, especially determining whether
    or not there was a "late cataclysm" or spike in impact cratering at
    3.9 Ga. Further, the early impact history played a role in the early
    atmosphere, early tectonics, and the delivery of volatiles. All of
    these are tied to the important Mars theme of "follow the water".
    Also, impact history may have a role in planetary asymmetry that is
    relevant to understanding both the Moon and Mars.

[]{.mark}

> Establishing a well-defined impact flux for the Earth-Moon system for
> the last 3.8 Ga is a step in better understanding the impact flux on
> Mars. Such an understanding will help to construct timelines for
> erosional, depositional, and volcanic features on Mars. Further, minor
> spikes in impact flux that have been suggested for the Earth-Moon
> system during this period of time may have been experienced by Mars.
> This clearly had an influence on evolution of life in the Earth-Moon
> system. Is it relevant for Mars?

C.  *Record of Volatile Evolution and Behavior**:*** As Mars and the
    Moon are at nearly opposite ends of the volatile spectrum for rocky
    planets, most of the volatile science studies to be conducted on
    Mars are not possible on the Moon. There are several special cases
    where the study of lunar volatiles may be relevant to Mars. One
    example is "energetic particles", whose composition and interaction
    have been well studied on the Moon and whose study on Mars will
    probably be limited to determination of near-surface exposure
    histories. The characterization and exploitation of possible water
    ice at the lunar poles may be important as a resource for human
    exploration. In addition, it provides insight into the transport of
    volatiles on airless planetary bodies. Another special case is the
    nature of lunar endogenic volatiles that provide insights into the
    nature of volatile reservoirs in early planetary mantles.

D.  *Astrobiology:* Astrobiology is the quest to understand how
    habitable planets form and how inhabited worlds evolve, as well as
    the prospects for life beyond the Earth. Therefore, astrobiology
    research questions provide many linkages between lunar exploration
    and Mars science goals. Historically, the Moon preserves unique
    information about events and processes that have affected the
    habitability of the entire inner Solar System, including early Mars.
    Such events include impact chronology (especially during the first
    billion years), the composition of large impactors and
    interplanetary dust particle (IDP) flux, the delivery of exogenous
    volatiles and organics molecules, history of solar activity (solar
    wind; flares) and the occurrence of nearby supernovae and gamma ray
    burst (GRB) events. The record of such events is obscured on Earth.
    Although it is somewhat better preserved on Mars, the lunar record
    is much more accessible. Hence, the Moon is the ideal place to
    improve our understanding of some of these events.

Fulfilling many of the scientific goals associated with these Moon-Mars
linkages requires the development and utilization of instrumentation
that is much more technologically complex than used by Apollo or current
Mars exploration missions. Deploying (either robotically or by humans)
and maintaining a long-lived and highly sensitive geophysical network on
the Moon is relevant to deploying such a network on Mars. The sampling
of diverse and environmentally hostile terrains on both the Moon and
Mars is important for all themes listed above. Development of sample
collection strategies that extend the capabilities of humans through
robotics is critical. The development of deep drilling technologies
provides 1) access to regions that are unexplored by surface studies and
2) links between the surface and the deep planetary interior.

> []{.mark}

[]{.mark}

> **4.6 Completeness**

The MFLO-SAG was not able to identify any significant gaps in the form
of objectives of importance to Mars that are not present in the draft
list of lunar objectives.

> []{.mark}
>
> **4.7 Mars as a Core Theme for the Lunar Program**

[]{.mark}

The MFLO team considered several different programmatic options to
achieve the goal of keeping Mars exploration in the forefront of the
lunar program. Since the lunar program will serve as a precursor to Mars
exploration, it is important that the lunar program architecture be
consistent with achieving the needs of a Mars precursor program.

The options considered for keeping Mars as a signpost out in front of
the lunar program included:

1\) Describe Mars exploration as a core theme (or goal) of the lunar
program and use Mars exploration as a prioritization criterion for the
lunar objectives.

2\) Describe Mars exploration as a cross-cutting theme which may have
the effect of emphasizing the multiple linkages to Mars in many
different areas.

3\) Make Mars exploration a specific lunar objective. The specific tasks
associated with this objective would be broad and Mars-unique. This
would potentially ensure that components designed for use on the Moon
could be used with little or no modification on Mars.

4\) Describe Mars exploration as a prioritization criterion rather than
a theme or objective. If the intent is to use Mars-relevancy as a way of
optimizing the lunar program, this could be applied as a prioritization
factor to all of the lunar objectives.

The MFLO SAG consensus regarding the best way to ensure that the lunar
program is designed for maximum relevancy to Mars exploration is to
*leave Mars as a core theme within the lunar program*. Considering Mars
as a core theme within the lunar program helps to keep the relevancy of
the lunar objectives over a broad range of topics consistent with the
notion of utilizing the lunar program as a precursor for Mars
exploration. Additionally, using Mars exploration as a prioritization
criterion for the lunar objectives will also help ensure the maximum
utility of the lunar program for future Mars exploration.

**5. References**

Beaty, D.W., Snook, K., Allen, C.C., Eppler, D., Farrell, W.M.,
Heldmann, J., Metzger, P., Peach, L., Wagner, S.A., and Zeitlin, C.,
(2005). An Analysis of the Precursor Measurements of Mars Needed to
Reduce the Risk of the First Human Missions to Mars. Unpublished white
paper, 77 p, posted June, 2005 by the Mars Exploration Program Analysis
Group (MEPAG) at http://mepag.jpl.nasa.gov/reports/index.html.

Hinners, N.W., Braun, R.D., Joosten, K.B., Kohlhase, C.E., and Powell,
R.W., (2005), Report of the MEPAG Mars Human Precursor Science Steering
Group Technology Demonstration and Infrastructure Emplacement (TI)
Sub-Group, 24 p. document posted July, 2005 by the Mars Exploration
Program Analysis Group (MEPAG) at
<http://mepag.jpl.nasa.gov/reports/index.html>.

MEPAG (2006). Mars Scientific Goals, Objectives, Investigations, and
Priorities: 2006, J. Grant, ed., 31 p. white paper posted February, 2006
by the Mars Exploration Program Analysis Group (MEPAG) at
<http://mepag.jpl.nasa.gov/reports/index.html>.

Shearer, C., Beaty, D.W., Anbar, A.D., Banerdt, B., Bogard, D.,
Campbell, B.A., Duke, M., Gaddis, L., Jolliff, B., Lentz, R.C.F., McKay,
D., Neumann, G., Papanastassiou, D., Phillips, R., Plescia, J., and
Wadhwa, M. (2004). Findings of the Moon→Mars Science Linkage Science
Steering Group. Unpublished white paper, 29 p, posted October, 2004 by
the Mars Exploration Program Analysis Group (MEPAG) at
http://mepag/reports/index.html.

Space Studies Board (2002). *Safe on Mars: Precursor Measurements
Necessary to Support*

> *Human Operations on the Martian Surface*. National Research Council,
> National Academy Press, Washington, DC.

**6. Appendix**

Appendix 1 and Appendix 2 list specific lunar objectives with a
perceived relevance to Mars exploration in terms of preparation for
humans and science linkages, respectively. The charts also indicate the
relevance assessments regarding Mars for each lunar objective. Note that
these charts only contain those lunar objectives with a perceived
relevance to Mars exploration and other lunar objectives with no
perceived relevance to Mars are not listed here.

The information contained within the charts (Appendix 1 and Appendix 2)
is as follows. The "Objective ID Number" references the specific
objective originally listed in the draft lunar objectives. The "Name"
column describes this objective in more detail. Within the "Name"
category, cells in green represent the original text describing the
lunar objective while cells in blue were rewritten by the MFLO SAG to
provide more relevance to Mars. The "Prepare for Mars Priority"
(Appendix 1) and "Relevance to Understanding Mars" (Appendix 2) columns
indicate a high (H), medium (M), or (L) relevance to Mars exploration
(see detailed explanation of ranking definitions in Section 4.1). The
"Discussion" column captures the rationale of the MLFO SAG regarding the
assessment of each lunar objective.

Appendix 3 is a list of acronyms used in this paper.

**APPENDIX 1: Lunar objectives with relevance to preparation for human
Mars exploration.**

![](media/image1.wmf)

> ![](media/image3.wmf)

![](media/image5.wmf){width="7.5in" height="4.920138888888889in"}

![](media/image6.wmf){width="7.5in" height="4.680555555555555in"}

![](media/image7.wmf){width="7.5in"
height="4.863194444444445in"}**APPENDIX 2: Lunar objectives with
relevance to understanding Mars**

![](media/image9.wmf){width="7.5in" height="1.3173611111111112in"}

**APPENDIX 3. Acronym list**

EDL -- Entry, Descent, and Landing

ESMD -- Exploration Systems Mission Directorate

EVA -- Extravehicular Activity

GRB -- Gamma Ray Burst

IDP -- Interplanetary Dust Particle

ISRU -- In Situ Resource Utilization

ISS -- International Space Station

LAT -- Lunar Architecture Team

LEAG -- Lunar Exploration Analysis Group

LEO -- Low Earth Orbit

MEPAG -- Mars Exploration Program Analysis Group

MFLO SAG -- Mars Forward Lunar Objectives Science Analysis Group

MHP-LP -- Mars Human Precursor Lunar Program

MHP SSG -- Mars Human Precursor Science Steering Group

NASA -- National Aeronautics and Space Administration

PLSS -- Portable Life Support System

RFI -- Request for Information

SOMD -- Space Operations Mission Directorate

SMD -- Science Mission Directorate