FYI: Science Policy News

NASA Scrambles to Find ‘Viable’ Path for Mars Sample Return

OCT 27, 2023
NASA is developing a new architecture and annual budget profile for its flagship Mars Sample Return mission, which is facing billions of dollars in unanticipated costs, years of schedule delays, and a threat of cancellation from Congress.
Will Thomas
Spencer R. Weart Director of Research in History, Policy, and Culture
Mars Viking Orbiter Composite Widened.png

Mosaic image of Mars from NASA’s Viking 1 spacecraft.


NASA is considering major changes to its Mars Sample Return mission, MSR Program Director Jeff Gramling reported on Oct. 20 at a meeting of the Mars Exploration Program Advisory Group (MEPAG), a science community forum. He remarked, “We’re standing back with fresh eyes to make sure that we’ve got a viable and sustainable architecture that we’re taking forward.”

The architecture revision would be MSR’s third in two years. This latest rethink follows findings from an independent review board (IRB) that the mission is facing at least a two-year delay, that its costs have been underestimated by billions of dollars, and that altering its multivehicle architecture could increase its “resilience” against disruptions in plans. Gramling said the revision will also consider how to proceed within annual funding constraints, which could reduce disruptions to other projects in NASA’s Science Mission Directorate at the cost of further stretching out MSR’s development.

Ultimately, Congress will determine how much funding MSR receives each year, whether the SMD budget grows to accommodate it, and whether the mission should continue at all. For fiscal year 2024, which is just underway, Senate appropriators have proposed a severe cut for MSR and broached the prospect of cancellation. House appropriators’ plans for MSR remain under wraps, but their proposed SMD topline leaves no room to robustly fund it without imposing significant cuts across other science activities.

NASA and review board signal support for MSR

Notwithstanding its criticisms, the IRB report calls for MSR to continue and recommends that NASA better communicate its importance, pointing to its scientific value, its place in NASA’s Mars exploration plans, and its significance for U.S. leadership in space. It also urges NASA to dispel the idea that “canceling MSR necessarily means greater budgets for everybody else in the Planetary Science Division or even the Mars Exploration Program.”

NASA anticipates completing its formal response to the review, including any architectural revisions, by the end of March 2024. In the meantime, officials are saying that MSR remains an agency priority.

SMD deputy head Sandra Connelly, who leads NASA’s response team, told MEPAG, “It’s these flagship-type missions that really do inspire the world. So, they’re complex, they’re difficult, they’re costly. It’s worth the investment, and we’re going to make the investment as we assess the [IRB] recommendations and determine how to move forward.”

Planetary Science Division Director Lori Glaze characterized looming budget constraints as a storm to be weathered, noting they are linked to caps on federal spending that Congress and the Biden administration agreed to for this fiscal year and the next.

“We will get through and we can come through even stronger than we were before,” Glaze said, asking the science community to remain united around NASA’s priorities. She also observed that Congress’ steep ramp up in funding for MSR has come on top of funding for other activities, which has remained generally steady.


A chart presented by NASA Planetary Science Division Director Lori Glaze showing how Congress has increased the division’s topline to accommodate the ramp up of work on Mars Sample Return. Recent decreases in the Outer Planets and Ocean Worlds, Discovery, and Mars Exploration Program budgets respectively represent planned ramp downs in work on the Europa Clipper, Lucy and Psyche asteroid missions, and Perseverance rover.


Yet, both within and beyond the funding for those activities, NASA’s prioritization of MSR has already led it to defer requests for certain projects such as the Near-Earth Object Surveyor and the Heliophysics Division’s Geospace Dynamics Constellation. Delays to MSR will also likely push back future missions, such as a planned flagship mission to Uranus.

Such tradeoffs have raised hackles in Congress. Notably, while the Senate proposal would mainly take away rather than reallocate MSR’s budget, it does restore funding that NASA proposed to cut from heliophysics. That allocation likely reflects the influence of Sen. Jeanne Shaheen (D-NH), the Senate’s lead appropriator for NASA and a champion of heliophysics work at the University of New Hampshire.

There is also dissatisfaction around MSR in the planetary science community. MEPAG Steering Committee Chair Vicky Hamilton acknowledged there are concerns about individuals’ research and career trajectories as well as the value-for-money of missions’ science returns. While voicing her own support for NASA’s position, she said, “You should know that there’s no uniform perspective on the side of the steering committee about MSR and these concerns are held at all levels.”

New plans to balance budgets, schedule, and technical risks

Concerns about MSR predate the IRB, but the board’s report has clarified the scale of the difficulties surrounding the mission. According to it, there is “near zero probability” that NASA can launch MSR’s lander in 2028 as planned, or that the European Space Agency can launch the Earth Return Orbiter it is contributing to the mission in 2027. In addition, it assesses that NASA should expect to spend a total of between $8 billion and $11 billion on MSR.

The report criticizes NASA for adopting “unrealistic budget and schedule estimates from the beginning,” and notes NASA’s contribution to the mission was originally constrained to $3 billion. Last year, the National Academies’ decadal survey for planetary science ranked MSR as its top-priority mission and presented a figure of $5.3 billion for its cost, which includes a sample processing facility not considered in the IRB’s estimate.

The survey recommended that if MSR’s total cost exceeds $5.3 billion by more than 20%, NASA should “work with the administration and Congress to secure a budget augmentation.” However, the Senate appropriators’ proposal states that if MSR cannot meet the $5.3 billion figure, NASA should “provide options to descope or rework the mission or face mission cancellation.” That position is not Congress’ final word, though, and lawmakers may yet adopt a different policy.

NASA’s emerging approach is to keep MSR’s annual budget in check, in line with the decadal survey’s recommendation to keep that budget under 35% of the Planetary Science Division’s budget. The IRB also recommends NASA de-emphasize total cost as a “critical measure of MSR programmatic success” if the agency deems constraining the annual budget to be more important.

According to the IRB, beginning in fiscal year 2025 NASA will need more than $1 billion per year for three years to meet a 2030 launch date using the current mission architecture. Alternative architectures could keep yearly costs between $850 million and $1 billion with launch dates between 2030 and 2035. The report finds that plans presented in NASA’s fiscal year 2024 budget request to seek $950 million for one year and between $600 million and $700 million per year thereafter are infeasible.

In any event, MSR Program Director Gramling indicated NASA expects the MSR architecture review will unfold during a “skinnying down” of the mission due to looming funding constraints. He said Steve Thibault of the Johns Hopkins Applied Physics Laboratory has joined MSR as chief engineer and is leading a team that will identify two or three candidate architectures that NASA aims to winnow to one by March. He said NASA aspires to establish a baseline technical design, schedule, and cost estimate about a year from now, if funding permits.

An illustration of the current vehicle architecture for the Mars Sample Return mission

Mars Sample Return’s current multivehicle architecture comprises, clockwise from top left, up to two sample-retrieval helicopters, an orbiter contributed by the European Space Agency, an ascent vehicle to launch samples from Mars’ surface, a landing craft, and the Perseverance rover already on Mars.

(NASA / JPL-Caltech)

Gramling did not hint at what architectures NASA is considering or what target launch dates NASA might entertain. However, he said that substantial progress has already been made on various “building blocks” of the mission and that NASA believes much of that work can be integrated into a revised architecture. Congress has appropriated more than $1.7 billion for MSR to date.

The IRB report notes that the risks facing MSR’s current architecture include the aging of the Perseverance rover, which is the primary option for delivering samples to MSR’s sample launch rocket. The report also notes that, while Perseverance has left a depot of 10 samples that can be picked up by helicopter if it fails, there is great science value in samples the rover is still holding as well as those it has yet to collect. The report points to further risks associated with the degradation of the telecommunications infrastructure currently in Mars orbit and with MSR spending too much time on Mars’ surface.

According to the report, architectural revisions could involve steps such as reintroducing a “fetch” rover dropped from the mission in 2022, employing a radioisotope power source, and deploying new telecommunications assets to Mars.

Review board calls for mission management overhaul

Diagnosing how MSR arrived in its current position, the IRB report states that NASA did not apply lessons from a recent internal study on large missions. The agency failed to acknowledge uncertainties surrounding its estimates, underestimated the impact of recurring design changes, and implemented an “ineffective system of checks and balances.”

The report spotlights problems with MSR’s orbiting sample (OS) system, which will harbor sample tubes as they are launched from Mars, transferred to the ESA spacecraft, and returned to Earth. “Key partners at NASA centers and ESA report cost impacts, schedule delays, and the stress of personnel that are caused by repeated redesign of OS accommodations and interfaces,” it states.

More broadly, the report criticizes MSR’s organization and management, including that NASA leaders have not given the mission the attention its importance and difficulty demands. It urges, “The entire management and organizational structure for MSR should be revisited.”

Elaborating on that point to MEPAG, retired NASA official Orlando Figueroa, who chaired the IRB, remarked, “These are the kinds of things that occur under the radar right until you start penetrating and understand the tensions that were playing out throughout the program.” He added that unclear roles and lines of authority are “really a kiss of death for any program, if that is not attended to and attended to early.”

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