NASA scrambles to find “viable” path for Mars Sample Return

Editor’s note: This article is adapted from a 27 October post on FYI, which reports on federal science policy. Both FYI and Physics Today are published by the American Institute of Physics.

After receiving critical feedback from an independent review board (IRB), NASA is considering major changes to its planned late-2020s flagship mission to retrieve Martian rock and soil and bring them to Earth. “We’re standing back with fresh eyes to make sure that we’ve got a viable and sustainable architecture that we’re taking forward,” said Jeff Gramling, program director of Mars Sample Return (MSR), at a 20 October meeting of the Mars Exploration Program Analysis Group (MEPAG).

The IRB report calls for MSR to continue and recommends that NASA better communicate the mission’s scientific value, its place in NASA’s Mars exploration plans, and its significance for US leadership in space. But it found 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 latest revision, MSR’s third in two years, will also consider how to proceed within annual funding constraints, which could reduce disruptions to other projects in NASA’s Science Mission Directorate (SMD) at the cost of further stretching out MSR’s development. The revised plan is scheduled to be announced by the end of March.

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. Congress has appropriated more than $1.7 billion for MSR to date. 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 want to fully fund NASA’s $950 million request for MSR, according to a newly released document . They aim to meet a 2030 launch date while distributing budget cuts elsewhere across the agency’s science divisions, including planetary science.

At the MEPAG meeting, SMD 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 on for this fiscal year and next. “We will get through, and we can come through even stronger than we were before,” said Glaze, who asked the science community to remain united around NASA’s priorities. She also observed that Congress’s steep ramp-up in funding for MSR came on top of funding for other activities, which has so far remained generally steady.

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.

Concerns about MSR predate the IRB, but the board’s report has clarified the scale of the difficulties surrounding the mission. There is “near-zero probability” that NASA can launch MSR’s lander in 2028 as planned, the report says, or that the European Space Agency can meet its 2027 launch target for the Earth Return Orbiter that it is contributing to the mission.

The IRB assesses that NASA should expect to spend a total of $8–11 billion on MSR. The report criticizes NASA for adopting “unrealistic budget and schedule estimates from the beginning” and notes that 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 cost figure of $5.3 billion, which includes a sample-processing facility that was 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.” 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.” Negotiations with the House could result in some other policy.

Beginning in FY 2025, NASA will need more than $1 billion per year for three years to meet a 2030 launch date using the current mission architecture, according to the IRB. 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 FY 2024 budget request seeking $950 million for one year and between $600 million and $700 million per year thereafter are infeasible.

Gramling indicated that 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.

Gramling did not hint at what architectures NASA is considering or what target launch dates NASA might entertain. 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.

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, although 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, including the degradation of the telecommunications infrastructure currently in Mars orbit.

Diagnosing how MSR arrived at 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 also criticizes MSR’s organization and management. NASA leaders, it says, have not given the mission the attention that its importance and difficulty demand. “The entire management and organizational structure for MSR should be revisited,” the report urges.