Principles for Mars Sample Return

The Planetary Society believes in the scientific exploration of space, in an open and welcoming curiosity in its practice, and that we as a species are bettered by the effort to know the Cosmos and our place within it. The Society’s core pillars of interest are Planetary Exploration, the Search for Life, and Planetary Defense. The first two of these motivate our focus on NASA’s planetary exploration activities for human and robotic missions in our Solar System and beyond. These core interests guide our organization at all levels, from our outreach and education to our advocacy and policy development. These core interests follow a consistent commitment to science and exploration established by our founders over 40 years ago.

Mars Sample Return (MSR) touches upon nearly every aspect of The Planetary Society’s advocacy principles: it advances the search for life, is an outcome of the science-driven National Academies of Sciences Decadal Survey process, feeds directly into future human spaceflight at Mars, and is an international collaboration that simultaneously drives advances in technology and the fundamental scientific understanding of our Solar System.

Mars Sample Return’s execution is in trouble, however, as findings from the second independent review board found that the project’s current schedule and budget are untenable. Actions by the Senate to control MSR’s budget, however well-intentioned, combined with current political and budgetary uncertainty in the U.S., have led to layoffs and work stoppages across NASA centers and industry, almost certainly further delaying the effort and increasing its total cost.

As NASA and Congress reconsider the nation’s approach to Mars Sample Return, The Planetary Society believes that it must be reworked with the following principles:

(1) Support science by following the Decadal Survey’s recommendations

Mars Sample Return is the top priority of the current Planetary Science and Astrobiology Decadal Survey and the continuation of the previous Decadal’s top priority of a sample-caching Mars rover, currently on Mars and having cached more than half of the samples. The report was prepared with input from across the scientific community and represents the official consensus position of the U.S. planetary science community.

Planetary Science is not alone in having Decadal recommendations, and we note that MSR’s focus on the search for life beyond Earth is at the heart of the top flagship mission recommendation by the Astrophysics Decadal Survey as well. While we search for habitats and signs of life within our Solar System, the Habitable Worlds Observatory will search for biosignatures beyond. The U.S. has an opportunity to pursue these breakthrough projects by effectively following the scientific recommendations laid out by these respected processes.

(2) Mars Sample Return should be executed "with no increase or decrease" in its scientific scope

We are deeply concerned by efforts to decrease the quality of the returned cache, whether by limiting the geologic diversity of samples collected by the Perseverance rover or by decreasing the number of samples returned relative to the plan presented to the Decadal. Mars Sample Return was elevated as the priority flagship mission of the coming decade due to its immense scientific return, which in turn solely rests on the quality of the returned cache. Sacrificing the value of the cache will undercut the value of the Mars Sample Return effort, and reduce our future knowledge of Mars and our Solar System. Cutting back on MSR’s science return is not a prudent stewardship of funds nor is it in line with Decadal recommendations.

(3) Do it now

The Perseverance rover is on the ground now, collecting the samples. The hard-won operational knowledge of landing on and operating on this challenging planet is in the workforce now. NASA and ESA have invested in orbiters that are at Mars now, providing critical remote sensing data and communications relays to Earth for sample return mission landed ops. This infrastructure will not be in place forever, and it is not easily nor cheaply replaced — we would be wise to pursue Mars Sample Return now and take advantage of the hardware and human capability at hand. The European Space Agency is NASA’s partner, concurs with the priority and timeliness of the effort, and has already authorized a multi-billion dollar contribution for the 2020s and 2030s.

There is additional time pressure from the perspective of U.S. and European interests. The China National Space Administration recently announced its intention to conduct its own Mars sample return mission within the next decade. The U.S. and China are engaged in an economic competition that extends into global science, engineering, and technology sectors. Bold, challenging, and historic “mission firsts” like Mars Sample Return represent important geopolitical achievements that can propel peaceful economic and technological development, as well as serve as a statement of national values. NASA and ESA’s Mars Sample Return project represents their respective nations’ prioritization of scientific inquiry, their commitment to working peacefully with each other, and their shared interest in tackling challenging, inspiring problems that serve to enhance humanity’s understanding of the Cosmos.

(4) Do it with balance

No project should have a blank check. This is not the Cold War and Mars Sample Return is not Apollo. We acknowledge that the project will, by its nature, be expensive, and NASA and Congress must still maintain balance across the Planetary Science program and across the agency’s science portfolio. The Planetary Science and Astrobiology Decadal Survey has already provided guidelines for this situation that Congress and NASA should follow as mission architectures and timelines are reworked; namely, a set of decision rules and recommendations for Mars Sample Return as an annual percentage of the portfolio. Beyond the division-level prescription in the planetary decadal, we believe it is possible — and important — to make progress on the top Decadal priorities across NASA’s entire science directorate. This requires proper funding and political support from Congress and the White House and an improved management strategy for stability, with careful control over annual spending, to support NASA’s space science portfolio.

(5) Mars Sample Return is both a NASA and U.S. national priority in robotic and human Moon-Mars efforts

The benefits of Mars Sample Return extend beyond scientific knowledge. As the first launch off of another planet back to Earth, the project will serve as an invaluable precursor for human spaceflight at Mars and will provide critical data to define engineering needs for the first flight performance of a rocket in the Martian atmosphere, long-term propellant storage and reliability, and dust contamination. Mars Sample Return should be considered among NASA’s highest priorities and, if necessary, should be funded in part by NASA’s Exploration Systems and Space Technology Directorates as a key enabler of the Agency’s Moon-to-Mars effort.

Given these principles, The Planetary Society recommends the following:

  • That NASA treat Mars Sample Return as its highest immediate Solar System priority and execute the mission in a timely fashion while maintaining its scientific scope;
  • That NASA incorporate lessons from Mars Sample Return into its long-term human exploration and technology development plans and consider the project as a critical part of its Moon-to-Mars effort;
  • That the White House request, and Congress subsequently approve, a robust NASA Science Mission Directorate budget to, in part, enable the timely execution of Mars Sample Return consistent with the principles stated above; and
  • That, should additional funding not be available, NASA should maintain programmatic balance by reducing annual expenditures for Mars Sample Return by extending its schedule — not by reducing the mission’s scientific scope.

Mars Sample Return

Despite advances in space technology, certain science questions, including whether or not a Mars rock contains signs of ancient life, can only be answered in Earth-based laboratories.

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