GROUNDBREAKING MSR:

SCIENCE REQUIREMENTS AND COST ESTIMATES FOR A FIRST MARS SURFACE-SAMPLE
RETURN MISSION

Final Report

of the

Mars Sample Return Science Steering Group

Glenn MacPherson, Chair

October 1, 2002

# (For correspondence, please contact [**glenn@volcano.si.edu**](mailto:paul.r.mahaffy@nasa.gov), 202-357-2260, or [**David.Beaty@jpl.nasa.gov**](mailto:David.Beaty@jpl.nasa.gov), 818-354-7968) 

# This document is an abridged version of the original Oct. 1, 2002 report. The original report includes cost information which is potentially competition-sensitive, and which has been deleted. This report has been approved for public release by JPL Document Review Services (reference number CL#04-0549), and may be freely circulated. Suggested citation:

# 

MacPherson, Glenn J. (Chair), and the MSR Science Steering Group (2002),
Groundbreaking MSR: Science requirements and cost estimates for a first
Mars surface sample return mission. Unpublished white paper,
http://mepag.jpl.nasa.gov/reports/index.html.

**TABLE OF CONTENTS**

I. EXECUTIVE SUMMARY 3

II\. INTRODUCTION 4

III\. BACKGROUND 5

IV\. PROCESS 6

V. PATHWAYS TO A GROUND-BREAKING MARS SURFACE-SAMPLE RETURN

A. Revised Science Requirements for the First Mission 8

B. Mars 2009 MSL Connections to Groundbreaking MSR 14

C. Planetary Protection and Sample Sterilization 16

VI\. RESULTS OF THE INDUSTRY STUDIES FOR GROUNDBREAKING MSR:

COST AND RISK ANALYSIS 19

VII\. SUMMARY 26

REFERENCES 27

APPENDICES

Appendix A: MSR SSG Members 29

Appendix B: Summary of original industry studies

for a MSR mission with MER-class mobility and science package 31

Appendix C: The First Returned Mars Samples:

Science Opportunities; JPL Publication 01-7 33

Appendix D: The Probable Science Return from

an MSR Mission with No Mobility (internal SSG report) 43

Appendix E: Industry reports for Groundbreaking MSR, as

presented to the MSR SSG on June 23-24, 2002 48

GROUNDBREAKING MARS SURFACE-SAMPLE RETURN:

SCIENCE REQUIREMENTS AND COST ESTIMATES FOR A FIRST MISSION

Final Report of the Mars Sample Return Science Steering Group [^1]

I.  **EXECUTIVE SUMMARY**

The first surface-sample return mission from Mars, termed Groundbreaking
Mars Surface-sample Return, should consist of a simple lander whose only
tools are an extendable arm with very simple sampling devices (e.g.
combination of scoop + sieve), and a context camera (in addition to the
navigation camera). Given that the mission will visit a site that has
been previously characterized as interesting by other landed or orbital
missions, the samples collected (minimum of 500g of fines + rock
fragments + atmosphere) will provide critical fundamental knowledge
about the evolution of Mars' crust and climate and thereby enable the
selective targeting of more sophisticated sample return missions in the
future. These successor missions will in turn be able to better address
the question of whether indigenous life does or once did exist on Mars.

II. **INTRODUCTION: SURFACE-SAMPLE RETURN MISSIONS AND A BALANCED MARS
    EXPLORATION PROGRAM**

The collection and delivery of samples from an extraterrestrial body to
Earth for laboratory analysis is the cornerstone for understanding that
body's formation and evolution. No robotic instruments can begin to
provide the precise analytical measurements that can be obtained using
laboratory instruments unconstrained by weight or volume or power
limitations, under the most carefully controlled analytical conditions
with samples that are ideally prepared for each type of analytical
method, and subject to complete flexibility and repetition as the
analytical results require. Detailed and precise understanding of
crustal evolution with time, determining unambiguously the existence and
nature of minute amounts of prebiotic or even biotic compounds,
determining the timing and nature of any wholesale planetary
differentiation, understanding the nature and formation of any regolith,
determining the nature and abundance of volatiles, and deciphering the
evolution of any atmosphere, are only possible through laboratory
analysis of samples. Conversely, such results are most meaningful when
understood in the context of global and regional data sets than can only
be provided by extensive orbital and *in situ* landed missions. This has
been vividly demonstrated by experience from exploration of Earth's
moon. The detailed knowledge of lunar rocks and fines that was obtained
by laboratory analysis of the Apollo and Luna materials is taking on new
meaning in light of the global chemistry data sets provided by the
Clementine and Lunar Prospector missions. An ideal balanced program for
exploring any rocky or even icy body in our solar system will consist of
a judicious and cost effective combination of orbital, landed *in situ*,
and surface-sample return missions. CAPTEM (The Curation and Analysis
Planning Team for Extraterrestrial Materials) has used the lunar analogy
to propose just such a balanced program for the exploration of Mars
(CAPTEM, 2000).

As was the case for the Moon, the very first samples returned from the
surface of Mars will provide such a monumental leap in knowledge over
what has been gleaned remotely that such a "groundbreaking" mission not
only can, but also arguably should, be very simple in its design and
goals. Indeed, the recently-released NRC Decadal Survey for Solar System
Exploration (National Research Council, 2002b) considers a first Mars
surface-sample return mission to be so important that the report ranked
it as the highest priority for a large (\>\$650 m) Mars mission in the
next decade. The NRC report also correctly emphasizes that studies of
the martian (SNC) meteorites are no substitute for surface sample
return: the meteorites are a biased sampling of Mars, having no context,
that include only impact-resistant igneous rocks of limited diversity
(*e.g.*, no "andesite"). Most importantly, they do not sample either
regolith or sedimentary rocks that are of such vital importance to
understanding Mars past climate and habitability.

The results of a first surface-sample return mission will greatly
influence the planning of additional *in situ* and sample return
missions. A useful analogy is geologic fieldwork. During a first field
season in a new area on Earth, a geologist identifies and maps
field-recognizably distinct units and then brings back samples of those
units at the end of the season in order to understand exactly what those
units are made of. The second and subsequent field seasons proceed in a
more systematic fashion because the nature of the units is known and
specific hypotheses can be tested in the field. By the end of
approximately 2011, we will have a wealth of high-resolution imaging and
global chemical and mineralogical data for the surface of Mars but we
still will not really understand the temporal geologic, atmospheric, or
hydrologic evolution of Mars. We will be fully ready to bring back
samples of Mars' rocks, regolith, and atmosphere for analyses in order
to formulate informed hypotheses about martian processes and evolution.
The main requirement for such a mission is careful site selection,
chosen either to ensure sample diversity (e.g., an outwash plain, where
the planet has already done the work of assembling a diverse collection
of materials in a confined area) or else to maximize the potential for
information about water, climate, and habitability.

The first surface-sample return mission will provide the insight
necessary for more carefully targeted subsequent missions such as those
that will specifically look for evidence of ancient -- or even extant --
martian life. Our global theories about Mars will certainly be greatly
revised in response to the wealth of information provided by the first
returned samples. Accordingly, subsequent sample return missions will
require more precise landing capabilities, mobility, and sophisticated
on-board science packages in order to go to and sample specific
locations and even outcrops.

The first surface-sample return mission will also shed new light on
orbital spectroscopic and *in situ* data, which can be firmly calibrated
against the mineralogy and chemistry determined with great precision in
terrestrial laboratories.

Finally, the samples from the by the first Mars surface-returned mission
will provide critical data for estimating the hazards that may be
present during eventual human missions to Mars (*e.g.* see the recent
NRC report *Safe on Mars*; National Research Council, 2002c).

For all of the above reasons, the following report takes the position
that a first sample return -- the Groundbreaking Mission -- not only can
but should be very simple in its design and implementation, that it
should be the first of several sample return missions that are
increasingly sophisticated in their approach (sampling, on board
science, targeting precision), and that this first surface-sample return
mission can confidently be targeted on the basis of comprehensive global
and regional imaging, chemical, mineralogical and physical data that is
now or soon will be available for Mars.

# BACKGROUND

Robotic sample return missions from Mars have been seriously
contemplated since the late 1970s (the time of Viking), but the cost and
complexity of such missions have resulted in continual postponement.
Publication by McKay et al. (1996) of possible evidence for ancient
martian microfossils caused greatly renewed interest in Mars sample
return, but an accelerated (and overly ambitious) schedule of Mars
exploration over the subsequent several years led to the loss of two
spacecraft in 1999 and a complete rethinking of the Mars Exploration
Program.

A new science advisory group was formed in 2000, called the Mars
Exploration Payload Assessment Group (MEPAG), which involved over 100
representatives from diverse science disciplines related to Mars
exploration. The first major product from this group was publication, in
2001, of *Scientific Goals, Objectives, Investigations, and Priorities*
(MEPAG, 2001). This document lays out four well-established overarching
goals for Mars exploration: Determine if life ever arose on Mars;
Determine past and present climate on Mars; Determine the evolution of
the surface and interior of Mars; and, Prepare for human exploration.
Analysis of returned samples in terrestrial laboratories is highlighted
in the report as an essential step to achieving many of the detailed
objectives of all four goals.

NASA contracted with four industry groups (Ball Aerospace, Boeing,
Lockheed-Martin, and TRW) in 2000 to independently design and estimate
the costs for a Mars sample return mission, with a nominal launch date
of 2011. The reports were completed in 2001 and delivered to NASA.
Although differing in details, all of the original mission designs
include a rover with extensive on-board science instrument packages
(those original full reports are not included here; however, see
Appendix B, tables B-1 through B-3 for science requirements and
summaries of the original mission concepts). Most of the designs
mitigate mission risk by some level of redundancy of landers, launches,
or both. As proposed, cost estimates for the original industry designs
approach \$3 billion in real year dollars. When normalized (by JPL) to
single-launch/single-lander configurations, the industry designs have
estimated costs in the range \$1.3 billion to \$2.0 billion ('02
dollars; see Appendix B, table B-4).

Because of revised US Government budget priorities following 9/11/2001,
NASA was asked to re-examine its own priorities regarding missions. In
the case of the Mars Exploration Program, the high proposed cost of
sample return became especially problematic. NASA convened three special
science "steering groups" in early 2002 to study: (1) a discovery-driven
set of alternative pathways for exploring Mars during the period
2010-2020; (2) possible revisions to the science requirements under
which the 2001 industry sample return mission studies had been made,
with the goal of simplifying them in order to reduce cost yet still
achieve important science goals; and (3) specific astrobiology science
goals in the Mars Exploration Program. These three steering groups are
designated as subcommittees of the MEPAG.

Dr. James Garvin, Mars Exploration Program Scientist, chartered the Mars
Sample Return Science Steering Group (MSR SSG; #2 above) as follows:

***In light of new information on the implementation of Mars Sample
Return and in response to NASA\'s FY\'03 budget, a Science Steering
Group for MSR Studies has been convened. This group will support NASA\'s
formulation of a discovery-driven Mars program for the second decade of
exploration. The MSR SSG, together with JPL and industry, will focus on
identifying affordable MSR missions that address the high priority
science goals for Mars.***

####### PROCESS 

The MSR SSG met for the first time on February 19, 2002 in Scottsdale
AZ. Subsequent teleconferences were held on April 18, May 2, May 16, May
30, and August 29. The full committee met again on June 23-24 in Arcadia
CA. A draft report was turned in to NASA on July 12, 2002, and a
preliminary presentation of findings was made to the Solar System
Exploration Subcommittee (SSES) of the Space Science Advisory Committee
(SScAC) on July 17, at NASA Headquarters. A revised report was presented
to, discussed, and approved by the full MEPAG at its meeting on
September 5-6, 2002 in Pasadena CA. Comments received at that meeting
have been incorporated into this final report.

At its first full meeting in Scottsdale AZ in February 2002, the SSG
heard summary presentations by the four industry groups on their
earlier, mobile mission designs and cost estimates. As a result of these
presentations, the committee realized that four factors were primarily
responsible for a high estimated cost of "unconstrained" MSR. First are
some of the science requirements themselves, especially the mandate for
mobility (rover) and an extensive on-board science package. A second
factor is the large degree of technology development required to be
ready for MSR, such as precision landing, hazard avoidance, and the Mars
ascent vehicle (MAV). Third, because all of the proposed mission
concepts require successful completion of a long serial string of
difficult events, the primary means of ensuring mission success was to
add redundancy for the most risky events, *e.g* multiple landers/MAVs.
Finally, there are stringent planetary protection requirements
concerning both forward-contamination of Mars by terrestrial biota and
back-contamination of Earth by putative martian organisms. Of the four,
the science requirements are most clearly within the committee's charge
to address and as a consequence occupied most of its time during the
period 02/2002 to 06/2002. However, such clear and unanimous concerns
and recommendations regarding the other three were made by the industry
groups, independent reviewers, and JPL engineers that this report
addresses them as well, in the form of "findings" that we hope NASA will
take very seriously.

Our first step, at the February meeting in Scottsdale, was to re-examine
the science requirements that guided the industry teams in developing
their original mission concepts for MSR in 2001. In particular, the SSG
tried to determine whether all of the existing science requirements were
appropriate for a [first]{.underline} surface-sample return mission and
whether removing any would significantly reduce cost without seriously
impacting the expected science return. Two such science requirements
were identified as having the greatest cost leverage: the need for
surface mobility to achieve sample diversity, and the need for a highly
capable on-board science package to identify and carefully select
samples of the highest scientific interest.

As detailed in the following section, the committee at that first
meeting recommended a revised set of science requirements and, together
with JPL, asked the four industry teams to redesign their MSR concepts
under the new guidelines. In addition, JPL took the further step of
relaxing all other requirements such as specific risk abatement. The
overriding MSR SSG goal in this exercise was to learn the answer to a
question that had never before been asked: What is the real cost of a
[simple]{.underline} yet scientifically fully defensible surface-sample
return mission from Mars?

The four industry teams were asked to complete their revised studies by
mid-May, with the goal of making formal presentations to NASA/JPL and
the MSR SSG in June. In addition, JPL revised its own MSR mission design
and cost estimates ("Team X"). Finally, JPL contracted with SAIC Inc.
and Aerospace Corporation to act as independent cost reviewers of the
four industry and JPL studies. The industry, JPL, and independent review
presentations to NASA and JPL (with some SSG members in attendance) were
made on June 5-6 in Pasadena. Shorter summary presentations were made to
the MSR SSG proper on June 24 in Arcadia.

In parallel with these revised costing efforts associated with the
revised science requirements, the committee proceeded through a series
of teleconferences to explore two other possible cost savings options:
(1) how MSR might be directly linked with the 2009 Mars MSL mission,
through shared technology or by having MSL accomplish some of the tasks
necessary for MSR and thereby reduce requirements and costs for MSR; and
(2) whether it might be scientifically reasonable to perform on-board
sample sterilization prior to their arrival on Earth and thereby greatly
reduce the expenses derived from planetary protection requirements.

**V. PATHWAYS TO A GROUND-BREAKING MARS SURFACE-SAMPLE RETURN**

#### A. Revised Science Requirements for the First Mission 

The original mission requirements as delivered by JPL to the industry
contractors in 2000 are listed in Table 1. These were the starting
points for the SSG deliberations at the 2/2002 meeting.

The SSG learned that, of these, two of the dominant cost drivers are the
requirement for mobility and the requirement for an extensive science
instrument payload. Revising those requirements for the first MSR
mission necessitated reconciling the differing objectives of the
geologic and astrobiologic science communities. Whereas the Apollo
experience demonstrated that regolith from almost anywhere on an ancient
planetary surface will contain interesting lithologies that bear on a
wide range of planetary evolution questions, the search for possible
ancient microbial life demands more carefully targeted samples. The
breakthrough to revising the original MSR science requirements came
through two insights. First, a key step in deciding where to go for the
more targeted astrobiology missions is to obtain basic representative
samples of martian lithologies in order to begin to understand martian
rock/hydrosphere and rock/atmosphere interactions -- essential to
understand martian climate and habitability. These first samples will
almost certainly not contain information about past or present life, but
they will tell us a great deal about the martian environment and its
habitability. The second insight is that, through careful site selection
for a first mission and a focus on regolith with entrained rock
fragments, we will not need a rover, sophisticated on-board science
instruments, or complex

***Table 1. Original Level-1 Science Requirements for MSR Industry
Studies***

![](media/image3.wmf)

sampling tools in order to obtain important and diverse basic samples
that will be informative in terms of martian physical and environmental
evolution. In short, t[he first MSR mission will enable later, more
targeted missions aimed at astrobiology]{.underline}. Because the
existing body of knowledge of Mars materials is so small, all samples
collected by the groundbreaking first surface-sample return mission will
have a clear and disproportionate influence on planning for the
targeting and instrumentation of subsequent MSR and *in situ* landed
missions. These findings at the first SSG meeting led to a unanimous
agreement that mobility (a rover), a sophisticated on-board science
package beyond a simple context camera and an arm camera, and a need to
be able to follow any particular precursor mission (e.g. Mars 2009 MSL)
to any precise location on the surface of Mars should not be
requirements for the first MSR. They were eliminated from the guidelines
under which the revised industry mission designs and cost estimates were
to be made. The only location requirement is that this first MSR be
capable of going to a site that is selected based on information from
any previous orbital or in situ missions to be scientifically
interesting, and whose units are likely to be of sufficient extent that
a landing precision approximately comparable to that of MSL (\~ 10 km)
will put the sample return mission in a position to sample them among
nearby surface rocks. From the point of view of astrobiology, this
translates to going to a site that is likely to contain significant
evidence for the former presence of surface water and hence, past
climates and habitability.

**Finding: The first, Groundbreaking MSR mission must support the
science objectives of Astrobiology, and it will do so by simply landing
at a site shown by prior missions to contain information about Mars
present and past climate and habitability. Mobility on the surface of
Mars is not required. This mission should provide guidance for
subsequent Mars sample return missions with increased probability of
returning direct evidence of past or present life on Mars.**

**Finding: Landing precision comparable to that of Mars 2009 MSL \[\~ 10
km\], and sufficient to assure landing safely, is adequate for the first
mission if geologic units having lateral extents of \>10-100's of km are
targeted. Analyses of returned samples can be generalized to the rest of
each unit.**

The original sample requirement for a minimum of 500 grams of sample
that must include regolith and wind blown fines, rock fragments, and
atmosphere is still considered essential and thus retained in the
revised requirements. The outstanding science that can be accomplished
with precisely this suite of martian samples has been described in
detail by the Mars Sampling Advisory Group of the MEPAG (MEPAG, 2001b;
[attached]{.underline} as Appendix C) and further refined in our own
studies as reported in Appendix D. Analyses of the samples in
terrestrial laboratories will inherently result in discovery-driven Mars
science, providing fundamental data addressing first order questions
about the evolution of Mars crust and mantle, paleoclimate and the role
of surface water, and the evolution of Mars' atmosphere. Finally, the
material properties derived from the laboratory studies will inform the
planning for the eventual safe human exploration of Mars (e.g. National
Research Council (2002c).

# Finding: By collecting samples of fines (fine grained regolith and wind-blown dust), small regolith rock fragments, and atmosphere, the Groundbreaking MSR mission will achieve science goals fundamentally important to the Mars Exploration Program as defined by MEPAG. 

Central to the discussion in that document (Appendix C) was that
acquiring rocks, and not just fines, greatly increases the science
value. Available evidence suggests that a suitable rock-rich sample
suite can very likely be collected without requiring a rover or
extensive on-board instrument suite. Images from the Viking and
Pathfinder sites (e.g. Fig. 1) show that the martian surface is covered
by four types of material: 1) *in situ* regolith, containing material
with

![](media/image4.png)

Figure 1. Photograph of the martian surface at the Pathfinder site,
showing regolith (rocks + underlying fine-grained blue-gray material)
and reddish wind-blown sand.

grain sizes ranging from fines (\< several mm) to rocks that are meters
or more in diameter; 2) dust (particles a few microns in diameter) that
settled from the atmosphere; 3) wind-blown sand; and 4) materials
developed in place by inferred weathering processes, forming rock
weathering rinds, duricrust, and other products. Based on the image in
Fig. 1, the Pathfinder site had many or all of these different materials
within a very short distance of the spacecraft, and they would have been
very accessible to the kind of arm + scoop suggested for Groundbreaking
MSR. Most notably, there are many rocks in the area that are
fresh-looking (blue-gray rather than red), in the \<3cm size range, and
suffered no apparent damage when the rover drove over them (they aren't
dirt clods). Based on likely crystal sizes in a variety of possible
martian surface materials, the minimum rock size that is necessary for
integrated mineralogic and geochemical work (especially isotopic age
determinations) is in the range 0.5-10 mm (Table 2; see also Appendix
D). Diversity considerations suggest sampling a larger number of rock
fragments in the smaller end of the size range (0.5-1.0 mm), but
relatively few rocks larger than about 2 cm (\> \~12 g) as these would
take up a disproportionate amount of mass. Evidence from Pathfinder
suggests that a suitable abundance of rocks in these size ranges was
available within 1-2 meters of the lander (Appendix D). Recognizing that
the Pathfinder site may be unusually rich in small rocks, nevertheless:

Finding: Assuming that Groundbreaking MSR goes to a site similar to the
Pathfinder site, and assuming an extendable arm with 2-meter reach and
\~20 cm depth capacity, there is a high probability that the mission
will succeed in achieving the stated sampling requirements.

The lander would likely include a context camera to provide panoramas
for targeting and document the sampling area. Beyond this camera,
however, the only sampling tools essential to achieve the required suite
of samples are very simple. For example, a scoop and sieve working with
a second camera on the end of an extendable and maneuverable arm, plus a
gas-tight seal on the sample canister, would achieve mission goals. A
sieve provides the ability to specifically acquire rock fragments in
addition to the scoop-acquired fines. Other simple sampling devices
might be considered (see below). The arm camera would provide close-up
documentation of samples and the sampling processes, including imaging
the insides of any trenches dug to characterize potential stratigraphy.
As the regolith and rocks chips are already mixed on the martian
surface, there is no requirement for individual sub-containers for each
individual chip or samples (however, this might still be desirable, e.g.
to separate wind-blown sand *vs.* regolith fines; much more
investigation is required to determine the cost impact relative to
benefits for Groundbreaking MSR). Moreover, because the samples will all
be analyzed with maximum precision and flexibility in Earth
laboratories, there again is no need on this first mission for on-board
science analytical instrumentation.

The committee discussed at length three issues related to sampling
instruments. The first is the possibility of retaining from the original
requirements a regolith auger, in order to be able to obtain samples
from as deep as perhaps one meter below the surface that might be
informative regarding both the putative oxidant layer and also
subsurface ice or water. The second possibility is to have a mini-rock
corer on the end of the sampling arm, as an optional sampling device in
order to ensure getting fresh rock samples from fragments that might
have weathering rinds. The third possibility is to have a separate
container for obtaining a dedicated atmosphere sample. There was
insufficient time to determine the cost and engineering repercussions of
these options, although the science gains are obvious. For example, the
committee concluded that a mini-corer is a more sophisticated tool that
might best be considered for missions subsequent to the first MSR. Yet,
at a site with fewer small rocks than the Pathfinder site but abundant
large rocks, a corer would help to ensure that actual rocks were
collected as part of the sample suite. The committee decided NOT to make
the auger, rock corer, or even a dedicated atmosphere container a
requirement for Groundbreaking MSR, based solely on the unknown cost
implications. NASA is urged to conduct more extensive studies to
establish whether any of these options could in fact be incorporated on
the groundbreaking MSR [without major impact to cost]{.underline} or
design. If the impact is large, these options should not be pursued for
the Groundbreaking MSR but definitely considered for subsequent
missions.

**Finding: A simple context imager, an extendable robotic arm with
arm-camera, simple sampling devices (for [example]{.underline}, a
scoop + sieve), and a sealable gas-tight sample canister, are sufficient
on-board sensing and sampling systems for Groundbreaking MSR.**

![](media/image1.wmf)

![](media/image1.wmf)

###### *Table 2. Estimated requirements for rock fragments that will be most useful for a variety of science investigations. (Summarized from Appendix D)*

The original landing location requirements would enable MSR to literally
follow Mars MSL anywhere on the planet. This becomes problematic (thus,
potentially, costly) at high latitudes and high elevations. Also, it is
conceivable that in 2011 NASA might conclude that the site (s) visited
by 2009 MSL is less interesting scientifically for sample return
considerations than, say, one of the two MER '03 sites. Finally there is
the finding, described earlier, that the only requirement for
Groundbreaking MSR should be the capability of visiting a general site
or unit deemed to be interesting based on the results of any previous
landed or orbital mission. In the revised requirements, therefore, the
SSG eliminated the latitude and elevation requirements. Landing
precision was required simply to be comparable to 2009 MSL, basically
taking advantage of the technology developments required by the latter
mission.

The resulting revised set of science requirements for a first,
groundbreaking MSR mission are summarized in Table 3. [These revised
requirements]{.underline} [formed the basis on which the four industry
groups and JPL re-designed and re-costed a first Mars sample return
mission]{.underline}. Table 4 compares the basic mission architectures
of the original ("MER-class") and new groundbreaking MSR missions.

Given the wealth of information about Mars that will be obtained by all
of the orbital and in situ missions flown in the decade 2000-2009, there
is no scientific reason that an intelligently-planned Groundbreaking MSR
mission cannot be conducted soon after the MSL mission in 2009. The
validity of the current Mars exploration strategy (orbiters, smart
landers, sample return) cannot be verified until this final element is
undertaken at least once. The NRC Decadal Survey for Solar System
Exploration (National Research Council, 2002b) urged that Mars surface
sample return be undertaken as soon as possible in the decade 2013-2023.

**Finding: The first MSR should be flown at the earliest possible time
following the completion of those missions now identified through 2009
MSL .**

***Table 3. Revised Science Requirements: Ground-Breaking Mars Sample
Return***

+-----------------------------------------------------------------------+
| -   **500 gm**                                                        |
+-----------------------------------------------------------------------+
| -   **Samples of rock, regolith, atmosphere**                         |
+-----------------------------------------------------------------------+
| -   **Land in a scientifically interesting area, as determined by     |
|     previous *in situ* or orbital missions, with landing precision    |
|     comparable to MSL (10 km)**                                       |
+-----------------------------------------------------------------------+
| -   **Context camera for sample collection, selection, and            |
|     knowledge**                                                       |
+-----------------------------------------------------------------------+
| -   **Samples held at temperatures below \<50oC \***                  |
+-----------------------------------------------------------------------+
| -   **Mission launch: 2013**                                          |
+-----------------------------------------------------------------------+
| -   **Mission duration \< 5 years**                                   |
+-----------------------------------------------------------------------+
| -   **Option to break apart the mission, with elements launched from  |
|     earth in separate launch opportunities (for example 2013, 2016)** |
+-----------------------------------------------------------------------+
| -   **Planetary protection working goals (requirements t.b.d.)**      |
+-----------------------------------------------------------------------+
| 1.  **10^-2^ forward**                                                |
+-----------------------------------------------------------------------+
| 2.  **10^-6^ backward**                                               |
+-----------------------------------------------------------------------+

*\* This is [not]{.underline} a requirement for active refrigeration,
but rather, for insulation against heating during Earth atmosphere
re-entry. Temperature maxima/minima should be recorded.*

***Table 4. Comparison of Sample Return Concept Designs:***

***Ground-Breaking vs. MER-Class***

![](media/image1.wmf)

##### B. Mars 2009 MSL Connections to Groundbreaking MSR 

The committee looked at various ways in which prospects for
Groundbreaking MSR could be enhanced by linking it with the Mars MSL
mission in 2009. Of particular interest are whether science tasks
essential to Groundbreaking MSR might be accomplished by the prior
mission, and how much technology and technology development can feed
forward from MSL to MSR.

One of the first possibilities the SSG investigated was whether the 2009
Mars MSL mission could use its advanced sampling and science instrument
package to identify samples of particular interest, and then either
collect them and cache them all in one place for later retrieval by MSR,
or else collect them and keep them for later rendezvous with MSR. While
it is scientifically very tempting to use MSL functionality to enhance
MSR, it quickly became evident to the SSG that the technological
difficulties of attempting either option, plus the greatly increased
complexity (and cost) to the 2009 MSL mission itself, rule out either
possibility.

# Finding: Attempting to use the 2009 Mars MSL mission to cache samples for or deliver them to the subsequent Groundbreaking MSR mission will likely result in unacceptable cost increases and risk, and daunting technological difficulties, for one or both missions.

However, there are a number of other surface science operations that can
be conducted by 2009 MSL using its strawman instrument package, and
which will greatly aid in the later surface operations of Groundbreaking
MSR by allowing sample acquisition to proceed more quickly and
effectively. It will be particularly important to learn how to recognize
and collect key samples for return to Earth.  These operations will be
important regardless of whether MSR goes to the same general site as
MSL. The proposed operations by 2009 MSL are appropriate and need not
impose any additional costs, hardware, or technology development
constraints on that mission.

Where 2009 MSL can be of greatest immediate benefit to Groundbreaking
MSR is in shared technology and technology development. Especially if
Groundbreaking MSR follows MSL by only 1-2 launch opportunities, the
most cost effective and efficient course of action is to build the basic
platform of both missions to a common design that can be adapted to
their differing payloads (*e.g.* MSL rover *vs.* MSR Ascent Vehicle).

# *Mars 2009 MSL Science Feed-Forward TO MSR*

One category of MSL surface operations that would benefit MSR even if
MSR follows MSL by only one launch opportunity includes those that
provide information that will test sampling and collection methods, and
establish simple criteria to recognize interesting and diverse samples
quickly. Groundbreaking MSR will need to be able to find the "right"
samples quickly. [Examples]{.underline} of such enabling 2009 MSL
operations include:

1.  Do pebbles with different compositions have different morphologies?
    Can one reasonably identify differing basic rock types from a meter
    distance or more by external morphology and surface texture. Can
    2009 MSL identify different grain morphologies and test to see if
    their composition correlates to their morphology?

2.  Are there other camera-viewable properties that can be used to infer
    composition? One could hope that the weathering rinds on grains
    retain some signature of the rock composition on which they are
    developed. Spectral data from 2009 MSL could be used to look for
    sample diversity and then correlate the observed spectra to basic
    rock composition. If a camera with some spectral discrimination is
    used for MSR, this prior experience will help select diverse
    samples.

3.  Measure geochemical gradients in the martian shallow subsurface, to
    support the sample collection strategy for MSR scientific
    investigations. In particular, use MSL to measure the oxidation
    gradient, which is needed to predict the depth where we could expect
    to begin to sample any reduced carbon.

4.  It would be valuable to know the physical state of the rocks and
    pebbles. Do pebbles have unaltered rock in their centers? Are most
    of the small objects on the surface just weathered "dirt clods"?
    This is important for "grab" sample strategies that will be using
    scoops, rakes, etc. What is the minimum rock size needed to have
    some amount of unaltered material in its interior? (It may be
    possible to get some data on this from MER).

Another category of 2009 MSL surface operations would benefit MSR only
if MSR follows MSL by more than one launch opportunity. However, other
missions prior to 2009 MSL (e.g. MER 2003) might address these
objectives as well:

1.  Measure the lithologic diversity of the surface rocks in at least
    one geologic environment. For Groundbreaking MSR, this will give
    some idea of the number of pebbles needed to achieve a reasonable
    level of diversity. For subsequent and more capable MSR missions,
    this will provide information to estimate how much lateral mobility
    is needed by MSR to achieve lithologic diversity.

2.  Measure the size distribution in the martian regolith. This will
    help determine the sampling strategy needed to acquire a rock of
    minimum size in Groundbreaking MSR.

3.  Measure the concentration of volatile components in prospective
    samples (especially regolith). This is needed to design sample
    preservation strategies and hardware. Are there other
    characteristics of martian samples for which action is needed to
    assure preservation?

# *Mars 2009 MSL Technology And Design Feed-Forward TO Groundbreaking* *MSR*

The following are [examples]{.underline} of technology can be shared by
MSL and Groundbreaking MSR, thus reducing the development costs and
risks for MSR. If Groundbreaking MSR were scheduled only 1-2 launch
opportunities after 2009 MSL, this engineering would need to be adopted
with minimal modification.

1.  Lander platform design suitable for carrying either a rover or a MAV
    (or possibly, for a later MSR, both). A lander platform of this
    design will be consistent with: (1) a landed mass of 1500 kg; (2) a
    surface payload mass of approximately 750 kg and volume of 7 cubic
    meters compatible with a MAV and a rover; and (3) live platform
    surface operations through successful injection of the returned
    sample into Mars orbit.

2.  EDL system, including precision and robust landing, scalable to
    support a landed mass of 1500 kg and compatible with the lander
    platform design capabilities articulated in item #1 above. Such an
    EDL system will allow incorporation of an aeroshell with a diameter
    of at least 4.5 meters for consistency with the aforementioned
    capabilities.

3.  Sample transfer technology including selection, transport and
    subsequent verified transfer to and containment by the receiving
    element.

4.  All aspects of sample acquisition, including mobile collection of
    diverse samples of rock and soil, as well as robotic arms, scoops,
    rakes etc. or even a drill. Included within this is demonstration of
    robotic sample collection and caching systems (such as was partly
    already done for the original Athena payload), and sample
    acquisition autonomy.

##### C. Planetary Protection and Sample sterilization

##### 

Planetary protection requirements and science considerations mandate
that not only must the outgoing MSR spacecraft be free to terrestrial
organisms to a specified level (protection against forward
contamination; see Table 2), but the returning spacecraft must break the
chain of contact so that no martian materials will be carried outside of
the sample container (protection against backward contamination). In the
original industry presentations given at the 02/2002 meeting of the MSR
SSG, the technology development to mitigate backward contamination was a
significant driver of cost and complexity. Moreover, although the cost
of building a sample receiving facility on Earth to contain potentially
biohazardous materials was not included in the estimates of any of the
industry teams, such cost is likely to be significant. These
considerations raise the possibility of sterilizing the samples prior to
their arrival back on Earth. The methods of sterilization considered
were irradiation and either dry heat or heat in combination with some
chemical agent.

Sterilization might plausibly be implemented at any phase in a sample
return mission. On the surface of Mars the samples might be heated in a
container on the rover, the lander, or the ascent vehicle. In space the
samples could be heated in a container in the ascent vehicle or in the
return vehicle. Following landing on Earth the samples, the container,
or even the entire spacecraft might be heated in a receiving facility.
Each option carries safety and scientific advantages and disadvantages.

Sterilization on Mars would have the advantage of occurring very early
in the mission, allowing the maximum range of later options. Conversely,
it imposes significant additional mass / power / volume constraints on
the mission due to the necessary sterilization and verification hardware
that must be included on the landed spacecraft. Also, it does not
address "breaking the chain of contact". Finally, venting of any
released volatiles (from the sterilization cycle itself) to the Mars
atmosphere results in complex pressure management design issues and the
possibility of recontamination. Sterilization in space allows
sterilization and verification hardware to remain on the orbiter and
hence does not impact the lander itself. Also, it can better achieve
"breaking the chain of contact", and venting of released volatiles to
space would minimize the possibility of recontamination. The
disadvantage of sterilization in space is that the sterilization and
verification hardware must remain operational in orbit.

Finally, sterilization of the samples after delivery to Earth frees the
entire spacecraft from any additional constraints imposed by
sterilization and verification hardware**.** Venting of released
volatiles can be controlled. However, this option does not address
"breaking the chain of contact" due to possible dust on the outer
surface of the return vehicle.

Heat sterilization is the most effective, but from a MSR scientific
point of view also the most controversial. To give some indication of
the temperatures involved, consider the following:

-   The highest temperature at which microbial growth has been
    documented is 113oC (Stetter, 1996), although the absolute limit
    remains to be determined.

-   A report from the National Research Council (1998) states: "A
    theoretical 160oC upper limit on growth (at 1 atm pressure) is
    dictated by the thermal instability of macromolecules, membranes,
    and other cellular structures, but growth at temperatures even
    higher cannot be discounted when all environmental parameters (such
    as high pressure) are considered. Because the upper limit for growth
    will depend on high pressure, and the environments likely to be
    encountered in sample return missions will be at low rather than
    high pressure, the theoretical 160oC upper temperature limit for
    growth is reasonable."

-   Protocols for dry heat sterilization of medical instruments
    typically range from 140oC for 3 hours to 170oC for 1 hour (National
    Research Council, 2002).

-   The NASA-certified dry heat sterilization of the Viking landers
    involved heating both spacecraft to 135oC for 24 hours prior to
    launch (National Research Council, 2002).

Unfortunately, heating to temperatures near the upper end of these
ranges has significant effects on other properties of the samples,
especially dehydration or other structural breakdown of possible martian
minerals that would be important clues in "following the water". As a
reasonable limiting case, heating to 200oC would [strongly]{.underline}
affect the following (data from Gooding, 1990; Neal, 2000; Kotra et al.,
1982; Golden et al., 1999; Biemann et al.,1977; Brinton et al., 2001):
Carbonate phase transitions, salt mineral / water isotope exchange,
water ice / vapor isotope exchange, capillary water mobilization, brine
liquefaction, gas desorption, CO~2~ ice evaporation, water ice
transitions, salt mineral H~2~O(+) loss, clay mineral H~2~O(-) loss,
remanent magnetism, zeolite dehydration (partial), clay / zeolite /
water isotope exchange (partial), maghemite / hematite transition
(partial), Al,Fe oxyhydroxide H~2~O(+) loss (partial), clay mineral
H~2~O(+) loss (partial), partial noble gas loss; at least partial loss
of volatile organics including saturated and polycyclic aromatic
hydrocarbons, and at least partial racemization of amino acids. Effects
on higher temperature rock components and properties would be minor,
such as: rock morphology / density / porosity, soil particle size /
morphology, petrography, non-volatile chemical composition, silicate and
oxide mineralogy, many isotope ratios including those used for
radiometric age determination.

Note that many of the most sensitive properties are those relating to
water and organic compounds. Yet, the primary drivers behind the current
Mars Exploration Program are to [follow the water]{.underline} and
[search for signs of ancient or extant indigenous life]{.underline} of
the surface of Mars. Thus, heat sterilization of the entire sample
payload represents a fundamental philosophical disconnect with the
entire program. The committee cannot rationalize destroying most or all
evidence of the principal things we are going to Mars to seek.

# Finding: Heat sterilization of Mars samples prior to Earth arrival is irreconcilable with the most important scientific goals of the Mars Exploration Program. This option should not be considered, regardless of possible cost savings.

Sterilization of the samples by irradiation (gamma) in space or on the
surface of Mars is believed to be far less destructive of the sample
properties than heat sterilization. However, understanding the
efficiency of this process and the technical (and political)
difficulties of implementing it are beyond both the expertise of the MSR
SSG and the time frame of the committee's operation. We note with
interest that proposals do exist for in-space sterilization of Mars
samples using radionuclides. These should be studied in detail, both for
feasibility and for the effects on organic and inorganic materials
similar to those expected from MSR. In particular, it must be shown that
sterilization by irradiation would not also (like heat) irreparably
destroy the scientific value of the samples with respect to Mars
Exploration Program goals.

# Finding: Sterilization of Mars samples by radionuclide irradiation may be a feasible path to cost savings for Groundbreaking MSR, but much more study is needed to establish the viability and effects on materials.

Although the nature and cost of a Mars Sample Receiving Facility (SRF)
are outside of the purview of the MSR SSG, its potential high cost to
the overall Mars Exploration Program negatively impacts the viability of
Mars sample return itself. For example, one concept of the SRF involves
a complex facility combining elements of both a clean room and a
biohazard containment facility -- something that has never been built --
and containing a wealth of sophisticated scientific equipment. Yet a SRF
in some form clearly is essential, not just for MSR but also other
possible sample return missions of potential bio-interest. Owing to its
importance, high cost, and technological difficulties, diverse options
for a SRF must be studied in much more detail and a final concept
arrived at in order for implementation to begin as soon as possible.

# Finding: Diverse concepts for a Mars Sample Receiving Facility must be studied in great detail to arrive at a cost-effective final plan. This needs to begin soon, because of the large lead time that will be needed to plan and build and test such a facility.

######### VII. SUMMARY

**The collaboration between the MSR SSG, Industry, and JPL has defined a
first Mars Surface-sample return mission that is:**

1.  [Affordable]{.underline}

-   Simple sample acquisition \-- no surface mobility

-   Short-duration surface operations

-   In situ sensors limited to cameras

2.  [Scientifically valuable]{.underline}

-   Returns scientifically rich samples of regolith fines and rocks,
    wind blown fines, and atmosphere

3.  [Supportive of broad program goals]{.underline}

-   As defined by MEPAG, and consistent with the NRC Decadal survey

4.  [Has broad science community support]{.underline}

-   Approved by MEPAG

5.  [Credible]{.underline}

-   Multiple, independent organizations converged on similar mission
    architectures and costs

**In order to maintain a low cost profile for Groundbreaking MSR, the
Mars Program should:**

1.  [Prevent the science requirements from escalating]{.underline}

2.  [Initiate as soon as possible an aggressive technology development
    program that focuses on key high-risk elements of MSR]{.underline}

3.  [Design a program with a high degree of technological commonality
    among the upcoming series of Mars landers starting with 2009
    MSL.]{.underline}

**REFERENCES**

Biemann, K., Oro, J., Toulmin, P., III, Orgel, L.E., Nier, A.O.,
Anderson, D.M., Simmonds, P.G., Flory, D., Diaz, A.V., Ruchsneck, D.R.,
Biller, J.E. and LaFleur, A.L. (1977) The search for organic substances
and inorganic volatile compounds in the surface of Mars, *Journal of
Geophysical Research*, 82, 4641-4658.

Brinton K. L. F., A. Belz, and G. D. McDonald (2001). Amino acid
racemization on Mars. *Abs. Pap. ACS 211*, GEOC-172.

CAPTEM (Curation and Analysis Planning Team for Extraterrestrial
Materials): [Jolliff]{.smallcaps} [B. L., Keller L. P., MacPherson G.
J.,. Neal C. R, Papanastassiou D. A., Ryder G., Shearer C. K. and Papike
J. J.]{.smallcaps} (2000) A balanced model for exploration of the
terrestrial planets: Lessons from the lunar experience. *Concepts and
Approaches for Mars Exploration, July 18--20, 2000*; Houston, Texas

Golden, D.C., Ming, D.W., Lauer, H.V., Jr., Morris, R.V., Galindo, C.,
and Boynton, W.V. (1999) Differential scanning calorimetry of hydrous
minerals under Mars-like conditions: calibration studies for the Mars
'98 lander thermal and evolved gas analyzer (TEGA) (abstract). *Lunar
and Planetary Science Conference XXX*, \# 2027.

Gooding, J.L. (1990) *Scientific Guidelines for Preservation of Samples
Collected from Mars*. NASA Technical Memorandum 4184, National
Aeronautics and Space Administration, Washington, DC.

Kotra, R.K., Gibson, E.K., and Urbanic, M.A. (1982) Release of volatiles
from possible martian analogs. *Icarus*, 51, 593-605.

McKay D.S. et al., *Science* **273**, p. 924 (1996).

MEPAG (2001a) Scientific Goals, Objectives, Investigations, and
Priorities. [In]{.underline}: McCleese D., Greeley, R., and MacPherson
G. (eds) *Science Planning for Mars*. Jet Propulsion Laboratory
Publication 01-7 (53 pp)

MEPAG (2001b) The First Returned Mars Samples: Science Opportunities.
[In]{.underline}: McCleese D., Greeley, R., and MacPherson G. (eds)
*Science Planning for Mars*. Jet Propulsion Laboratory Publication 01-7
(53 pp)

National Research Council (1997) *Mars Sample Return: Issues and
Recommendations*. National Academy Press, Washington, DC.

National Research Council (1998) *Evaluating the Biological Potential in
Samples Returned from Planetary Satellites and Small Solar System
Bodies*. National Academy Press, Washington, DC.

National Research Council (2002a) *The Quarantine and Certification of
Martian Samples*. National Academy Press, Washington, DC.

National Research Council (2002b) *New Frontiers in the Solar System: An
Integrated Exploration Strategy. \[in press\]* National Academy Press,
Washington, DC.

National Research Council (2002c) *Safe on Mars*. National Academy
Press, Washington, DC.

51 pp.

Neal, C.R. (2000) Issues involved in a Martian sample return:
preservation and the Curation and Analysis Planning Team for
Extraterrestrial Materials (CAPTEM) position. *Journal of Geophysical
Research*, 105, 22,487-22,506.

Stetter, K.O. (1996) Hyperthermophilic prokaryotes. *FEMS
Microbiological Review*, 18, 89-288.

# APPENDIX A. MSR SSG Members

# MSR SSG Members

Carl Agee

Univ. New Mexico

Carl Allen

NASA Johnson Space Center

Ray Arvidson

Washington University

Jean-Pierre Bibring

Université Paris Sud

Daniel Britt

University of Tennessee

Jean-Louis Counil

CNES

Michael Duke

Colorado School of Mines

Jack Farmer

Arizona State University

Ronald Greeley

Arizona State University

Chris House

Penn State University

Laurie Leshin

Arizona State University

David Lindstrom

NASA Johnson Space Center

Glenn MacPherson

\[MSR SSG Chair\]

Smithsonian Institution

Steven Mojzsis

University of Colorado

Kenneth Nealson

USC

James J. Papike

Univ. New Mexico

Mark Saunders

NASA Langley Research Center

Roger Summons

MIT

Dawn Sumner

University of California, Davis

# 

# Jet Propulsion Laboratory

David Beaty

Frank Jordan

Richard Mattingly

Steve Matousek

Daniel McCleese

Dimitri Papanastassiou

Charles Whetsel

Richard Zurek

# 

# NASA Headquarters Officials

Orlando Figueroa

James Garvin

George Tahu

**Appendix D.**

**Probable Science Return from an MSR mission with no mobility**

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[^1]: See Appendix A for a list of members and other participants