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NATIONAL ACADEMY OF SCIENCES NATIONAL ACADEMY OF ENGINEERING INSTITUTE OF MEDICINE NATIONAL RESEARCH COUNCIL
June 18, 2004 Current Operating Status
International Cooperation for Mars Exploration and Sample
Return
4
Possible Cooperative Mission Modes and Their Implications
Various approaches to establishing cooperative investigation of Mars are possible.
For the purposes of this report, the essential aspects of the major approaches, and
their implications, can be captured by several general considerations.
The USSR has announced intentions for a Mars exploration program, which
appears to include in situ surface investigations with robotic rovers, orbiting
spacecraft, and sample return. In view of the USSR's announced intentions, the
major variables in the set of alternative program modes that the committee has
examined are the level of U.S. participation in Mars science and the character of
U.S.-USSR cooperation, if any. Three levels of U.S.-USSR cooperation in intensive
Mars exploration have been considered by the committee:
Independently conducted programs,
q
Split responsibilities and joint technical operations, and
q
A highly coordinated exploration program.
q
Each of the possibilities also assumes that other nations and space agencies
would play substantial roles in the planning and execution of Mars exploration
within a framework largely defined by the U.S. and USSR programs. The final
recommendations are based on an analysis of the implications, for the United
States, of each of these possibilities.
THE PRESENT STATE OF U.S. MARS INVESTIGATIONS AND PLANNING
At the time of this writing, the U.S. program for further, exploration of Mars consists
of the Mars Observer mission, scheduled for launch in 1992, as the only
specifically planned initiative. The broad survey measurements to be carried out by
Mars Observer address a number of important global- and regional-scale
questions. The overall understanding of Mars as a planet will be greatly advanced
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by the Mars Observer's mapping of the planet's surface structure and chemistry,
investigations of the atmosphere, and measurement of Mars's magnetic field, all of
which will set the stage for intensive investigations to follow. The very-high-
resolution images that will be obtained of selected small areas will also prove
important to the planning of future Mars surface explorations. NASA has
undertaken studies of possible future Mars exploration initiatives that might be
carried out either by the United States with the participation of international
partners or as, part of a truly joint international endeavor with comparable
contributions from one or more major partners. As yet, the United States has not
announced national plans to undertake any intensive investigations of the martian
surface.
Experience with the Soviet VEGA project, with the Phobos mission, and with
planning for follow-on Mars missions indicates that. the USSR will continue to invite
and welcome participation from scientists in Western nations, including the United
States. Should the United States fail to assume a major role in the exploration of
Mars, there is likely to be some opportunity for U.S. scientists to participate in
continuing Mars science through direct affiliations with the Soviet program or,
indirectly, through affiliation with scientific teams from the other nations that will
participate in a Soviet-led program.
However, if the United States forgoes a primary role in Mars exploration, then any
cooperation is likely to be restricted to a low level, and U.S. scientists are likely to
be involved only in minor or supportive roles as international leadership in this
historic scientific endeavor is assumed by the USSR. Primary consideration by the
USSR in planning its own projects would likely be directed toward cooperation with
European nations and space agencies, and the result would be a highly intensified
relationship between those partners.
VARIETIES OF U.S.-USSR COOPERATION
In this section, the committee summarizes an analysis of the major possible
approaches to U.S.-USSR cooperation and, for the purpose of this analysis, notes
that (1) the USSR has announced its intentions for Mars exploration in sufficient
detail to suggest the scope of that nation's plans and ambitions; (2) USSR leaders
have publicly stated a desire for cooperation with the United States in the
exploration of Mars; and (3) the USSR is conducting detailed discussions with
numerous other nations about the possibilities of participation in Mars exploration.
Therefore, the committee assumes that during the next two decades the USSR will
conduct a Mars exploration at a level approximating the announced plans.
Moreover, on the basis of the public pronouncements, the committee takes as
given that the USSR is open to international cooperation in a variety of modes,
depending on the desires of potential partners.
As has already been noted, the future vigor of U.S. programs and a U.S. posture of
international leadership in this area are not assured. However, the remainder of
this analysis assumes that the United States will engage in intensive Mars
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investigation beyond the Mars Observer. This analysis also assumes that any
cooperation will involve a program extending over a decade, entailing several
missions to several diverse sites on Mars, and including both in situ investigations
and sample return, as described earlier.
The committee considered many possible program scenarios, ranging from
strongly linked missions in which mission success would depend on the success of
mutual interactions, to more weakly coupled versions, with cooperation
implemented in a different way. The analysis of possible cooperative modes
includes consideration of several discriminating factors, including (1) impact on the
overall science return; (2) the possibility of reduced cost to the United States,
within a fixed anticipated overall science return; (3) impact on mission risk; (4)
impact on technology development; (5) susceptibility to concerns about technology
transfer; (6) contribution to enhancing scientific relationships with the traditional
U.S. partner nations; and (7) possible contribution to improving the U.S.-USSR
relationship. In addition, several other factors were considered, such as the
contribution to building U.S. national prestige.
Independently Conducted Programs
The lowest level of U.S.-USSR cooperation considered in this report involves a
situation in which each nation conducts an independent program of Mars
investigation with minimal levels of cooperation or coordination. At this level, it is
still assumed that the usual scientific interactions generally characteristic of basic
scientific research will continue to occur, including the exchange of data obtained
by the missions.
This level of cooperation does not preclude the possibility of some operational
coordination and interaction to take advantage of circumstances that might arise in
the conduct of the separate programs; however, it is assumed that, at this low level
of cooperation, such fortuitous possibilities do not play a major role in shaping the
plans of either nation. This is the level of cooperation that exists today between the
United States and the USSR. Examples include the use of one nation's spacecraft
as a communications relay for the other nation. Although `even this relatively low
level of interaction requires advanced planning during the spacecraft design stages
and for operations, the interfaces that are involved are generally simple and
straightforward.
With respect to the discriminating factors:
Science return. Assuming that a commitment to achieve the scientific
q
objectives is actually carried out, conducting independent programs may
have little fundamental effect on accomplishing the scientific objectives;
the United States is fully capable of accomplishing all Mars scientific
objectives. However, the ability to maximize scientific return within the
constraints of the present technical capabilities of the two sides would be
lost if programs were conducted separately.
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Cost. The cost of conducting an independent Mars exploration program
q
is significant. Assuming fixed scientific objectives, the United States will
be forced to provide full resources for carrying out an independent
program and for accomplishing the objectives, regardless of the plans
and programs of the USSR
Risk. The committee identified no inherent impact on mission risk from
q
conducting an independent program, inasmuch as this is the normal
mode of carrying out space science missions.
Technology development. The independent approach has the potential
q
to greatly benefit U.S. technology development. Planning and carrying
out an intensive program of Mars exploration and sample return will
focus development efforts and implementation in a variety of important
technological areas, including scientific instrumentation, propulsion and
launch systems, and robotics and artificial intelligence. Many of these
developments will have application to other activities on the ground and
in space.
Technology transfer. An independent program eliminates any additional
q
risk of technology exposure or transfer that might result specifically from
cooperation with the USSR.
Relationships with traditional partners. Inasmuch as the United States is
q
assumed, in this approach, to be conducting a Mars exploration program
of its own, then the usual opportunities will be available for cooperation
with traditional U.S. partners and allies. This would serve to reinforce a
significant area of existing cooperation and would provide many nations
with a path to Mars exploration as an alternative to, or in parallel with,
participation in a Soviet program.
U.S.-USSR relationships. An independently conducted program makes no
contribution to developing U.S.-USSR experience in cooperative technical and
social endeavors. It could also ignite a space competition similar to the race to the
Moon.
Split Responsibilities and Joint Technical Operations
In this approach the United States and the USSR would undertake a significant
level of joint technical operations within the context of one or more missions. The
planning and execution of such missions would be conducted collaboratively, and
the achievement of major mission objectives would depend on sustaining
successful cooperative efforts from the time of initial mission design through to the
completion of data analysis. This level of cooperation generally would involve
substantial hardware, software, and management interfaces at the level of major
spacecraft systems and at institutional and governmental levels.
There are potential advantages to this high level of U.S.-USSR cooperation. A
commitment by both nations to a fully cooperative venture of the magnitude and
duration of a Mars sample return program would have a greater, presumably
positive impact on U.S.-Soviet relations than would options involving lesser
degrees of interaction and reliance. A high level of cooperation would permit the
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undertaking of ambitious and scientifically outstanding missions, such as the return
of Mars samples from a diversity of terrains at less cost to each nation than if the
same set of missions were executed unilaterally, although this advantage also
accrues to some cooperative options that involve less entanglement at the systems
level. Finally, this high degree of cooperation would enable missions that take full
advantage of the complementary and mutually supportive capabilities of the two
space programs (e.g., the present advantage in .heavy lift capability of Soviet
launch vehicles and the advantage of high analytical precision, sophistication, and
computational capacity enjoyed by U.S. flight instruments and systems).
Against these potential advantages must be balanced several disadvantages. A
mission with a high degree of dependence on the cooperative efforts of both the
U.S. and Soviet space programs would sit as a potential hostage to political events
that might disrupt communication and interaction between the two nations.
Missions can be envisioned in which the science could be successfully
accomplished by either side even if the bilateral cooperation were truncated for
political reasons during the mission planning or operation stages. However, such
mission configurations either involve a considerable redundancy of effort,
substantially offsetting the cost advantage mentioned above, or admit the
possibility of a substantially degraded scientific return if full cooperation is not
sustained through the project. A project with a high level of U.S.-USSR
cooperation, if it is to yield a savings in cost over unilateral missions of similar
scope and if it is to take maximum advantage of the complementary capabilities of
the two space programs, involves the assignment of responsibility for major
engineering modules to one or the other nation. Whether either nation will agree to
relinquish to the other the development of major components of enabling
technology is not apparent. There is, in addition, a substantial burden on resources
and personnel involved in coordinating and managing the interfaces involved in
such intimate cooperation; this would be exacerbated by lack of experience in this
kind of activity. This burden would offset the potential savings to an unknown
degree and must be weighed carefully in assessing the financial implications of the
high degree of cooperation and mutual dependence involved in this approach.
In one frequently discussed example of a mission conducted at this level of
cooperation, one nation would build a lander and a sample-return vehicle while the
other nation would build a roving vehicle for collecting samples and conducting in
situ science. The roving vehicle could be carried on the same lander as the sample-
return spacecraft or on a separate lander, and one or both nations could launch
Mars orbiters to serve as communication links and to conduct global remote-
sensing measurements. Obviously, design and logistical considerations would
differ depending on the configuration of the one or more landed packages.
This type of mission seems attractive, from a cost standpoint, as an individual
mission: it would share the cost of an otherwise unilaterally executed rover and
sample return mission. Because the rover and the sample-return vehicle—with the
latter also assumed to have some limited sample-acquisition capability—each
would accomplish important independent scientific objectives, significant science
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would accrue even if one of the two vehicles were to fail. As long as the rover and
the sample-return vehicle were launched separately from Earth, the two parts of
the mission could also proceed independently of one another should political
considerations force a termination of cooperative efforts. However, the science
return would be severely diminished if the separate components were not able to
complete their combined, fully interactive mission. The lift capabilities of the launch
vehicles of the two nations-with the present Soviet capabilities far exceeding those
of the United States-and the present U.S. lead in technologies associated with the
rover, suggest that the most natural division of responsibilities would be for the
United States to develop the rover and for the USSR to construct the sample-return
vehicle.
Such an assumed configuration would, of course, leave the United States without
an independent sample return capability and would relinquish the actual return of
martian samples to the USSR (although in such a scenario the returned samples
would be jointly controlled by the two nations): This configuration also does not
acknowledge the Soviet interest in developing and deploying robotic roving
vehicles for use on Mars. If the USSR were to go ahead, in any case, with its plans
to develop rovers, the benefit to the USSR of cooperation with the United States
might be largely political and scientific, but the financial advantage to the USSR
would not be so clear. The longer-term scientific and political benefits of
cooperation for the United States would be partly offset by ceding the development
of Mars sample-return vehicle technology to the Soviet Union. Altogether, to the
extent that technology development is likely to be a major motivation on both sides
and to the extent that both launch capability and artificially intelligent robotic
technology are seen as desirable by both sides, it is likely that both parties will be
reluctant to abdicate the development of either technology.
The committee considered the possibility that this approach, taking advantage of
the existing complementary strengths of each side, might speed progress toward a
launch and result in the earliest initiation of Mars exploration and sample return.
The needed technological developments could proceed in parallel. However, the
technical, social; and political obstacles associated with inaugurating such a
complex cooperative effort in the absence of prior experience could be expected to
introduce delays that would be difficult to estimate a priori. Therefore, the
committee is not convinced that mission modes involving such very intimate
technical interdependence and joint activities at Mars would indeed lead to the
most rapid initiation of Mars exploration.
With respect to the discriminating factors:
Science return. This approach potentially allows the greatest
q
optimization of overall science return within the constraints of the present
technical capabilities of the two sides. With nontechnical restrictions
removed, the project could be planned to take advantage of the best
capabilities, wherever those might reside.
Cost. The cost of conducting missions involving split responsibilities and
q
joint technical operations on Mars is significant. Assuming fixed scientific
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objectives, then each side would have responsibility for only a part of the
overall system, thus opening the possibility for considerable cost
savings. However, there are significant costs associated with
establishing cooperation of this kind between two nations on opposite
sides of the globe, with little prior cooperative experience, and with,
poorly established communications. These costs would offset an
unknown fraction of the savings that might otherwise be realized.
Risk. This approach must be considered to be inherently very risky. The
q
United States and USSR have no prior experience with the degree of
cooperation necessary to carry out a technical project of this complexity
or magnitude. There are no previously established modalities of
cooperation and relatively few existing lines of communication. Each side
has little preexisting working knowledge of the other's technical and
management practices or institutions. The demonstrated stability of the
relationship is such as to at least raise concerns, at: this time, about
relying on the consistency of the relationship over a period of a decade
or more into the future. The failure of all or part of the system as a
consequence of these risks would, at best, result in a severely degraded
scientific return.
Technology development. This approach minimizes the effort to develop
q
the necessary technology by taking advantage of the best capabilities
available on each side and by dividing the responsibility so that neither
side is responsible for all aspects of a mission. However, it is not clear
that either side will wish to yield to the other the most challenging and
beneficial of the technology developments.
Technology transfer. This mode of cooperation inherently involves the
q
exposure and transfer of large amounts of technology and technical
knowledge.
Relationships with traditional partners. In this approach, the opportunities
q
for participation by traditional U.S. partners and allies would occur within
a multilateral framework shaped by agreements between the United
States and the Soviet Union. This modality would foster international,
multilateral approaches to technical cooperation.
US-USSR relationships. This approach has the potential to make a large
q
and positive contribution to developing cooperative relationships
between the United States and the USSR.
A Highly Coordinated Exploration Program
In this approach, the United States and the USSR would agree to conduct a highly
coordinated program of intensive Mars exploration and sample return missions at
roughly equal levels of scientific and technical commitment. The two sides would
work together at all stages, including the initial planning of scientific objectives,
experimental approaches, principles of sample collection, and site selection.
However, the two sides would conduct their own self-contained and independently
designed missions, with specific interaction at Mars limited to the coordination of
networked investigations, when that is beneficial, and to mutual support and
backup of communications and data telemetry. The post-mission scientific
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analyses and sample distribution would be conducted with a high degree of
cooperation and collaboration. This approach would also permit the United States
and the USSR to carry forward, in their individual fashions, other aspects of
international cooperation. European scientists and agencies would undoubtedly act
to .enhance their scientific participation in the context of opportunities arising in the
U.S. and Soviet programs.
The approach of conducting a highly coordinated program of separately
implemented missions captures elements of each of the other two approaches
discussed above. On the one hand, the scientific objectives would be fully met. On
the other hand, within fixed scientific objectives, a large cost advantage is
apparent. Recognizing that the scientific objectives dictate a sequence of several
missions, each side would need to commit to roughly one-half of the needed
missions, assuming cooperation in the selection of sites and investigations.
The committee considered a number of variations on this approach, which have
the effect of increasing the level of joint technical operations while still remaining
within the framework of coordinated missions conducted separately. One variant at
this level of cooperation could be constructed so as to take advantage of the
simultaneous presence of two groups on the martian surface. For example, in the
case that both nations mount a complete surface-rover and sample return mission,
it would be able to choose complementary landing sites and rover traverse paths
so as to optimize the return of a diversity of samples, visit a wide variety of
geological features and units, and deploy network instruments over a geographical
region that enhances the scientific return from those instruments. While scientific,
political, and social benefits of full cooperation would accrue from such a mission
configuration, there would be little if any cost penalty, above the cost of conducting
separate missions entirely. The failure of one of the missions would result in a
decrease of the overall scientific yield but would not precipitate a failure in the
coordinated program.
The committee also considered mission scenarios in which landing sites would be
coordinated and closely spaced so that each rover could conduct a traverse to the
sample-return vehicle of the other nation and deliver its collection to that vehicle.
Modest scientific gains might include a richer diversity of samples and an
enhanced opportunity for some in situ investigations (e.g., rover-to-rover
electromagnetic or seismic sounding) and network science (meteorology,
seismology, and magnetometry) experiments. A dual surface-rover and sample
return mission to landing sites situated within rover traverse range could provide
additional robustness if one of the roving or sample return vehicles were to fail
mechanically, although providing for this contingency would require substantial
advanced planning and hardware coordination. Based on the present state of
knowledge of the martian surface, the present limitations on achieving highly
accurate targeted landings, the uncertainties associated with operating rover
vehicles past unexpected barriers in the martian terrain, and the limited level of
enhancement in the scientific return that would occur from such complex
operations, the committee concluded that such complex mission scenarios were
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not warranted for early stages of Mars exploration, but might be considered for
later missions.
The primary distinction between this approach and the approach based on split
responsibilities and joint technical operations is that each side would be fully
responsible for the overall systems involved in its own missions; there would be no
need for intimate technical and management interfaces at the system level that
could affect the likelihood of mission success. The committee believes that this
would relieve the large extraneous burdens and costs that otherwise could be
associated with a cooperative program. However, there would remain the highly
desirable possibility of exchanging scientific instrument packages built by one side
and included on a vehicle of the other side. The interfaces—both technical and
management—associated with such instrument exchanges are relatively simpler
than the overall system interfaces and could be designed so as to minimize the
likelihood of a major mission failure in the event of problems. Also, in this
approach, it is expected that there would be substantial collaboration and
exchange of personnel at the science-team level.
With respect to the discriminating factors:
Science return. This approach allows all of the scientific objectives to be
q
realized.
Cost. The cost-benefit impact of conducting a program of highly
q
coordinated but separately implemented missions is large. Neither side
would be responsible for mounting missions to the entire suite of
required sites on Mars. Assuming fixed science objectives, each side
would have responsibility for only a part of the overall program.
Moreover, because each side would be planning and carrying out its own
missions, the overhead costs associated with implementing close
technical and management interfaces would be eliminated.
Risk. Risk is minimized in a program that has a high level of cooperation.
q
Because each side would be implementing missions on its own, the
interfaces would be minimized. There would be no risk of mission failure
due to technical, management, or political failures.
Technology development. This approach provides each nation with the
q
advantages of undertaking full technical development—in the areas of
spacecraft launch systems, automation, and scientific
instrumentation—needed for Mars exploration and sample return.
Technology transfer. This mode of cooperation minimizes the transfer of
q
technology and technical knowledge. The committee believes that
incorporation of modular scientific packages from one nation on a vehicle
of the other nation could be accomplished with little concern that
unwanted technology transfer would occur.
Relationships with traditional parmers. Opportunities for participation by
q
traditional U.S partners and allies would occur within a context of two
separate programs carried out in parallel. It is likely that other nations
would seek the best opportunities, among those offered in the U.S. and
the USSR programs; for participating in Mars exploration.
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U.S.-USSR relationships. This approach has the potential to make a
q
large and positive contribution to developing cooperative relationships
between the United States and the USSR.
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