NASA’s planetary science program is in trouble. Last month NASA administrator Bill Nelson tested to Congress that the space agency’s Mars Sample Return (MSR) mission urgently needs a quarter-billion-dollar infusion of extra cash—and that even more budget busting may be on the horizon. That’s disturbing news, given the decades-long trend of NASA’s top-priority missions ballooning in cost and wreaking havoc elsewhere in the space agency’s science budget. Already MSR’s “too big to fail” status is impacting other NASA projects, and rumors are flying that more severe effects still lie in store. Seeing this all-too-familiar situation unfolding yet again, some space scientists are raising the alarm in hopes of somehow shoring up vulnerable missions against the coming storm.
“We have a very ambitious planetary program,” says Alan Stern, a planetary scientist at the Southwest Research Institute, who served as associate administrator of NASA’s Science Mission Directorate (SMD) from 2007 to 2008. “But there’s a point at which it becomes overly ambitious to the extent that it’s brittle. It’s not resilient to any failures.”
NASA currently operates planetary science missions across the solar system—orbiting the moon, piloting rovers and a robotic helicopter on Mars, rendezvousing spacecraft with asteroids, studying the atmosphere of Jupiter and even traversing the edges of interstellar space, to cite just a few. But the two largest missions on the horizon—so-called flagships—are MSR, a daring effort to deliver Martian rocks to Earth, and Europa Clipper, a spacecraft eponymously named for the icy, ocean-harboring Jovian moon it will survey for signs of livability.
Those missions are not going to be easy, particularly MSR, which many experts equal to multiple flagship missions in one. Already, NASA’s Perseverance Mars rover is collecting samples around its landing site and dropping them in sealed, sterilized tubes for future retrieval. Now NASA and its international partners are solidifying plans for MSR’s next steps. These include fetching the samples, launching them off the surface of Mars, rendezvousing in orbit around Mars with a homeward-bound transport and safely delivering the precious specimens back to Earth in a new fashion that does not risk contamination. None of these feats have been done before, and the margin for error is razor-thin. “It all has to work in a daisy chain,” Stern says. “Every one of those steps will be expensive and cannot fail—or the whole daisy chain falls apart, and you don’t get your samples back.”
Managing and mitigating MSR’s enormous technical risks is a key driver of the project’s skyrocketing cost. Its allotment from NASA’s annual budget has increased from $263 million to $653 million in fiscal year 2022 and then to $822 million in fiscal year 2023. Now, per Nelson’s congressional testimony, it needs another $250 million to stay on track. Yet MSR has not even reached formal confirmation yet—a milestone at which NASA codifies a mission’s technical details, cost and schedule baselines—meaning it is, in principle, still on the drawing board. “We’ve never done anything like this, so there will be surprises,” says Thomas Zurbuchen, associate administrator of NASA’s SMD from 2016 to 2022. “But the size of these corrections and the trends—they worry me.”
NASA’s finite budget is not the fundamental only resource that can be destabilized by missions that have grown too big to fail. The space agency’s personnel are a factor, too, because scientists and engineers can be pulled away from smaller or more nascent projects to help support larger ones that are considered more urgent. Whether in terms of dollars or person-hours, such shuffling can amount to “robbing Peter to pay Paul,” as a recent audit criticized. When the launch date for the Perseverance rover was fast approaching, for example, NASA’s Jet Propulsion Laboratory (JPL) channeled more resources into that mission—leaving MSR and Clipper depleted. Luckily, those efforts helped ensure Perseverance’s successful launch, landing and subsequent surface operations on Mars. “That’s because we did make those choices,” Zurbuchen says. “But then we had a hard time catching up.” NASA had to shift more resources to MSR and Clipper, leaving a mission to a metal-rich asteroid known as Psyche understaffed and ultimately causing it to miss its launch window. Such delays often stretch for years, incurring additional costs and further exacerbating budgetary woes all the while. “[NASA’s] planetary [science division] is under financial pressure because we’ve snowplowed all the problems forward,” Zurbuchen says.
To alleviate some of that pressure, NASA recently pushed back the launch date for a planned Venus orbiter known as VERITAS by at least three years—a decision that left many Venus scientists furious. “NASA is robbing money for a selected mission that they had baselined in their budget until as recently as last year,” says Paul Byrne, a planetary scientist at Washington University in St. Louis. “It has nothing to do with anything the [VERITAS] team has done. This was essentially collateral damage.”
And NASA’s planetary science division isn’t alone in suffering for a flagship’s sins; there is usually plentiful bread to spread around. One of the most high-profile recent cases, for instance, concerned chronic overruns on the James Webb Space Telescope (JWST), a flagship mission from the space agency’s astrophysics division. Originally estimated to cost $4.96 billion and launch in 2014, instead JWST launched in 2021 on a budget that had bloated to more than $10 billion. To pay for the overruns at the time, NASA terminated all participation in ExoMars, a robotic spaceflight program led by the European Space Agency and aimed at dispatching two ambitious missions to Mars (more recently, NASA rekindled some support for ExoMars). “During that time, when all that money was spent on James Webb, a lot of missions never happened,” Stern says. “Or they were cancelled, or they were stillborn through no fault of their own—just because NASA had to find the resources.”
Being “too big to fail,” however, may be an inevitable corollary to the high ambitions scientists, policymakers and the public alike typically assign to NASA—a systemic effect perhaps best summarized by JPL’s motto: “Dare mighty things.” Mark Sykes, CEO and director of the Planetary Science Institute, even argues that NASA’s system is meant to fail. Flagship missions deliberately take on tasks that defy easy execution, he says, meaning that cost estimates will always fall short. “At this time (and historically), the only buffer NASA has beyond extending these flagships out or canceling them is all the other mission and research programs, which they treat as a cookie jar to be raided as needed,” he says.
It is no wonder a wide swath of researchers are concerned that MSR will similarly raid other projects outside of planetary science. In fact, it already has. NASA’s 2024 budget proposal calls for delaying work on the Geospace Dynamics Constellation (a heliophysics mission) and slowing technology development for the Habitable Worlds Observatory (a future astrophysics flagship mission)—all because of MSR’s hefty price tag. The agency says that it stops there—for now, anyway. “As far as within the planetary portfolio, to this point, funding for MSR has been added on top of and over and above the planetary budget,” says Lori Glaze, NASA’s planetary science division director. “So we have not had to take from other parts of the planetary portfolio at this point.”
And yet there has been a lot of mysterious movement within many planetary science missions. VERITAS has been delayed. New Horizons, the spacecraft that gave us our first-ever detailed view of Pluto, has been moved out of the planetary science division and into the heliophysics division—effectively cutting short an “extended” phase of its mission that involved making novel astronomical measurements and potential further observations of icy bodies at the solar system’s scarcely explored outer limits. NASA has also cut funds for NEO Surveyor, a space telescope designed to detect near-Earth asteroids as part of the space agency’s planetary defense efforts. The agency only gave partial funding to the Dragonfly mission, an enormous nuclear-powered quadcopter meant to fly the frigid skies of Saturn’s icy moon Titan. The launch window for another Venus mission known as DAVINCI+ was pushed back, confirms James Garvin, DAVINCI+’s principal investigator at the Goddard Space Flight Center. And some scientists speculate that MSR’s overruns will place other Mars missions—such as the Curiosity rover—on the chopping block, too. “There’s no mission under development or flying or rolling that’s not at risk,” Sykes says.
Glaze, however, has an explanation for all these changes. Any true delay, such as that for VERITAS, was not caused by an overrun in MSR, she says, but rather by the COVID pandemic, which introduced new inefficiencies to preparations for missions such as Europa Clipper and Psyche that had to be absorbed into the budget. In addition, NASA has been forced to reckon with rising inflation, cost growth and extremely tight supply chains. Finally, she argues that MSR is not experiencing an overrun at all because the mission has not yet reached confirmation. “There is no such thing as a cost overrun because we haven’t actually set a budget yet,” she says.
But Sykes disagrees, given that NASA is already spending hundreds of millions of dollars now. “Glaze’s statement does not align with the facts on the ground,” he says. “This is what NASA does: they play with words; they play with money so that they can allocate it; they keep things in the dark to try to keep down the criticism.”
And even if MSR has not started to dip into other planetary programs, NASA itself apparently acknowledges this may only be a matter of time. In its budget proposal, the space agency stated, “Mars Sample Return costs may increase beyond the outyear profile shown in the budget, which would require either reduced funding for other science activities or descoping of this mission.” For this reason, NASA is creating an independent review board that will assess the current plans—essentially providing a final check and one last chance at some kind of course correction before the agency makes a commitment. “I don’t want it to impact anything else in the planetary science portfolio,” Glaze says. “But remember that we do have a fixed budget. And so we have to balance everything. And that’s our challenge: to try and work through how we balance all of those priorities.”
“Dare mighty things,” indeed. Casey Dreier, chief of space policy at the Planetary Society, notes that the extra $250 million needed this year alone will make it difficult to put VERITAS back in NASA’s budget at all. And other missions, such as a time-sensitive Uranus probe that tops a representative wish list from the US planetary science community, will likely never see the light of day. “The easiest mission to delay is the one that hasn’t started yet,” Dreier says.
To avoid such collateral damage, Stern suggests that NASA hit pause to rethink the mission’s architecture or to see if foreign partners could provide resources to lighten the budgetary load. Sykes has a bigger intervention in mind: Congress. “NASA is not at all being transparent about what they’re doing,” he says. “Congress needs to demand that NASA—mission by mission, project by project—tell what delays have been implemented over the past year and what budget adjustments have been made.” They need to shield other programs, or the fallout might just mean there is little of the planetary program left, Stern adds. “The American taxpayer and the science of this agency is suffering as a consequence of putting everything on the altar of MSR,” he says.
This is not to say that plenty of scientists are not thrilled by the prospect of MSR, given the likelihood that its results will rewrite textbooks and could conceivably even provide the first compelling evidence of extraterrestrial life. “These samples will be studied by literally thousands and thousands of scientists for decades to come,” says Laurie Leshin, JPL’s current director. But at what cost? “Mars doesn’t give up its secrets easily—that’s been its MO for years,” Dreier says. “The question will be: What price is the scientific community willing to pay—both in terms of literal dollars and other opportunities—for this mission?”