NASA’s Mars Sample Return has a new price tag—and it’s colossal

During his final months as the chief of NASA's science programs last year, there was one mission Thomas Zurbuchen fretted about more than any other—the agency's ambitious plan to return rocks from Mars to Earth. He supported the Mars Sample Return mission and helped get it moving through the agency's approval process. But the project threatened to devour the agency's science budget.

"This was the thing that gave me sleepless nights toward the end of my tenure at NASA and even after I left," said Zurbuchen, who left NASA after seven years leading its Science Mission Directorate at the end of 2022. "I think there's a crisis going on."

Now, Ars has learned, the problem may be even worse than Zurbuchen imagined.

According to two sources familiar with the meeting, the Program Manager for the mission at the Jet Propulsion Laboratory, Richard Cook, and the director of the mission at NASA Headquarters, Jeff Gramling, briefed agency leaders last week on costs. They had some sobering news: the price had doubled. The development cost for the mission was no longer $4.4 billion. Rather, the new estimate put it at $8 to $9 billion.

Moreover, this only represents the cost to build and test the different components of the mission. It does not include launch costs, operating costs over a five-year period, nor construction of a new sample-receiving facility to handle the rocks and soil from Mars. All told, the total cost of the Mars Sample Return mission is now about $10 billion.

About the mission

NASA and its international partners, including the European Space Agency, have wanted to return material from Mars for decades. It has also been a top priority of the scientific community, both to better understand the geological history of Mars as well as to look for evidence of life—past or present—on Mars.

After several iterations, NASA and its European partners settled on the project's current design last summer. Under this plan, NASA will develop a large "Sample Retriever Lander" that nominally is due to launch in 2028. After this vehicle lands on Mars, the Perseverance rover—which has been collecting and storing samples of Martian dust in 38 titanium tubes, each the size of a large hotdog—will bring its samples to the lander.

However, Perseverance may be a little long in the tooth by the time the lander arrives. Because Perseverance landed on Mars in 2021, NASA has decided it is too risky to count entirely on the rover being operational a decade from now. Accordingly, it plans to send two helicopters much like Ingenuity, which remains operational on Mars, as a backup plan to retrieve the samples.

Once delivered to the lander, these sample tubes will be placed aboard a rocket called the Mars Ascent Vehicle. This rocket is being developed by Lockheed Martin, and it will be stowed inside the lander. After launching from Mars, this rocket will release the "Orbiting Sample container" into Martian orbit, where it would be picked up by an "Earth return orbiter" built by the European Space Agency. This vehicle would carry the samples back to Earth orbit, where they would be released into a small spacecraft to land on the planet. NASA has created a video showing how this might work.

If NASA manages to develop and launch the Sample Retriever Lander by 2028, the samples could be returned to Earth in 2033. The problem is, no one expects the lander to launch in 2028. At this point, even 2030 looks like a stretch goal.

Mistakes were made

There is already a background buzz in the science community about cost overruns for this mission. After the space agency received $822 million in this year's federal budget for Mars Sample Return, it asked for $949 million in the fiscal year 2024 budget. This is far above the appropriations level sought even by the agency's most expensive science mission, the James Webb Space Telescope, on an annual basis. Additionally, in April, NASA administrator Bill Nelson warned of near-term cost growth in the mission.

Around the same time, NASA convened an "Institutional Review Board" to assess the agency's strategy for the mission and to make recommendations for its success. The board is being led by Orlando Figueroa, a retired deputy center director for science and technology at NASA’s Goddard Space Flight Center, and the group will publicly release a report in late August.

So what happened to drive these costs up?

Zurbuchen said there were "horrendous" technical mistakes made during the early planning phase at the Jet Propulsion Laboratory. The original concept involved sending everything on a single lander, including a small rover to "fetch" the samples from Perseverance. However the depth of this analysis was insufficient and included large errors about the mass of the landing legs and other factors. For a time, the plan had to evolve to add a second lander, which increased the cost by more than $1 billion.

Additionally, planning for Mars Sample Return got swept up in the management problems at the Jet Propulsion Laboratory, including staffing issues that led to the delay of the Psyche mission. An independent review found that the California-based field center, which leads many of the space agency's most prestigious science missions, had undertaken an "unprecedented workload" without possessing the resources needed to complete major projects.

Now it is undertaking its biggest mission ever in Mars Sample Return.

Current concerns

Ars spoke with a handful of NASA officials on background to discuss their concerns with the Mars Sample Return mission as it is conceived.

The biggest issue these officials have is that the Jet Propulsion Laboratory has never built a lander this large or complex in-house. With a mass of 3.4 metric tons, it is far larger than anything NASA or any other space agency in the world has landed on Mars. NASA says that, when it is fully extended, the lander will be 7.7 meters wide and 2.1 meters tall—about the size of a two-car garage.

Much of this mass will consist of fuel, due to the lander's size and its need to land very near the Perseverance rover. The NASA sources questioned why the Jet Propulsion Laboratory is taking on such a massive project when there are already workforce issues there, and much of the facility's staff will be tied up with the Europa Clipper project through most of 2024.

Due to these reasons, and the complexity of the program, it is almost certain that the launch date will slip to 2030 and very probably later. This means that if the program is costing $1 billion a year, or even more, it will continue to blow a major hole in NASA's planetary science budget, which is about $3 billion a year, for the remainder of this decade.

And these probably are not the end of the cost increases. This mission has not even reached the "preliminary design review" stage, a formal analysis of the mission and its design. Many planetary missions experience cost growth after that, including the Curiosity and Perseverance missions sent to Mars.

Implications for planetary science

To be clear, the Mars Sample Return mission is a high priority for the planetary science community. In the influential "decadal" survey published last year, which set exploration priorities for the 2023 to 2032 period, scientists confirmed this. However, they added a caveat on costs.

"Mars Sample Return is of fundamental strategic importance to NASA, US leadership in planetary science, and international cooperation and should be completed as rapidly as possible," the report stated. "However, its cost should not be allowed to undermine the long-term programmatic balance of the planetary portfolio."

The report stated that if the cost of the sample-return mission increased substantially (defined as 20 percent or more) or exceed 35 percent of NASA's planetary science budget in any given year, then NASA should not take that money from other planetary programs. Instead, the agency should ask Congress for a "budget augmentation."

The concern, says Paul Byrne, a planetary scientist at Washington University, is that Mars Sample Return risks becoming the planetary community's James Webb Space Telescope. For the better part of a decade, the Webb instrument consumed most of the astrophysics budget, to the detriment of other projects.

Webb has been a phenomenal success now that it is in space, Byrne said. However, the Webb telescope has benefitted a very broad segment of the space science community, from astrophysicists to astronomers studying exoplanets to planetary scientists. It has observed all manner of phenomena, both locally in our Solar System and all the way to the edge of the universe. The Mars sample return mission, while it may produce some spectacular science, will only benefit a fairly narrow segment of planetary scientists.

"It's the same scope as Webb in terms of cost but a much, much narrower scope in terms of science," Byrne said. "That’s really problematic."

NASA is selling the sample return mission as a "life-detection mission," which may find evidence of life on Mars past or present. However, Byrne said most planetary scientists think the mission has only a very low chance of actually finding definitive evidence of life. And if the sample return mission does not, he said, the general public is likely to ask why NASA spent $10 billion to study the geological history of Mars.

The planetary science community has already started to feel the effects of the sample-return mission's costs. The Veritas mission to Venus was delayed by three years, and the inventive Dragonfly mission to Saturn's moon Titan is receiving less money than it needs to launch on time, Byrne said. Additionally, the planetary community's next high priority mission, an orbiter to Uranus, is likely to get pushed years into the future.

So what to do?

NASA and policymakers do have some options if they want to control the costs of the Mars Sample Return mission.

Foremost among them is having a competition for the development of the large lander that is the centerpiece of the mission—and which will probably comprise about half of the total cost.

“Why are we not putting out a call and having an industry competition for people like Lockheed Martin, SpaceX, Blue Origin, Astrobotic, Intuitive Machines, and whoever else?" one NASA source asked. "They’re already building landers. Why can’t we ask them what they could do? JPL hasn’t even asked. We should be using a commercial, milestone-based approach.”

Zurbuchen said that NASA's current administration should be seriously considering this alternative if the Mars Sample Return mission is to continue.

"If I were in charge, I would develop a commercial option for the lander and seriously consider taking it away from JPL," he said. "Recall, this would be the first stationary lander done out of JPL. All others were built by Lockheed and that was before new capabilities by SpaceX and others."

Another option is removing the two Ingenuity-like helicopters currently attached to the mission. These are the "backup" plan to retrieve samples from Perseverance, if the rover is not healthy enough to deliver them to the stationary lander. Everyone loves Ingenuity, which has been a phenomenal success on Mars. But most likely Perseverance will be plenty healthy a decade from now, and adding two helicopters is akin to gold-plating the sample return mission while starving other missions like Veritas.

"To plan now for a failure on Perseverance, which may or may not ever happen, is such a luxury," one source said. "No robotic mission has ever done that before. If something does happen to Perseverance five years from now, why not deal with it then?"

For NASA, now is the time to make significant changes to the mission, before the agency completes a preliminary design review or goes through the Key Decision Point-C process later this year, after which NASA is more or less committed to the program.

Zurbuchen said that if the price really is escalating toward $10 billion at this early stage in the mission, NASA should think long and hard about whether this is really worth the cost.

"If the answer is this is not the decade to do it, my heart breaks because I put so much effort into it," he said. "But it is better to not do it than to torch the whole science community. We have to have the courage to say no. That’s the only way we earn the right to say yes."