NASA's Psyche Spacecraft to Attempt Rare Mars Flyby That Will Significantly Alter Its Trajectory

On May 15, 2026, a spacecraft the size of a tennis court will thread a needle 4,500 kilometers above the Martian surface at nearly 20,000 kilometers per hour. If the geometry holds, Mars will fling NASA's Psyche probe toward the asteroid belt with a free velocity boost worth months of thruster firing. If it doesn't, the mission's six-year journey to one of the solar system's most debated objects could become an expensive detour to nowhere.

The stakes are unusually high. Psyche already carries the institutional scar tissue of a missed 2022 launch window, an independent review that exposed systemic problems at the Jet Propulsion Laboratory, and a price tag that has climbed past $1.2 billion [1]. Now, with a single flyby maneuver, the spacecraft must execute a trajectory correction that few deep-space missions attempt at Mars — and none can afford to get wrong.

The Mechanics of a Borrowed Boost

A gravity assist works by exploiting a planet's orbital momentum. As Psyche falls toward Mars, it accelerates under the planet's gravitational pull. The encounter bends its trajectory and, relative to the Sun, increases its velocity — all without burning propellant. The maneuver is sometimes described as a cosmic billiard shot: the spacecraft "borrows" energy from the planet's motion around the Sun [2].

According to NASA's mission planning data, Psyche will be traveling at roughly 45,600 mph (73,400 km/h) relative to the Sun five days before the Mars encounter. Five days after closest approach, that figure rises to approximately 52,200 mph (84,000 km/h) — a gain of about 6,600 mph (10,600 km/h) [3]. At closest approach, the spacecraft will pass just 2,800 miles (4,500 km) from the Martian surface at 12,333 mph (19,848 km/h) relative to the planet [2].

Source: NASA JPL

Data as of May 10, 2026CSV

The spacecraft's operations team conducted a 12-hour trajectory correction maneuver on February 23, 2026, firing thrusters to fine-tune the approach. NASA has stated the spacecraft is "exactly on target" for the flyby [4].

For a mission that relies on solar-electric propulsion — a system that uses ionized xenon gas to produce gentle, continuous thrust — the Mars gravity assist is not optional. It replaces what would otherwise require enormous quantities of propellant, letting the planet's gravity "do some of the work instead of the propulsion," as NASA describes it [2]. The total journey to asteroid Psyche covers approximately 2.2 billion miles (3.6 billion kilometers), with the spacecraft set to enter orbit around its target in late July 2029 [3].

A Mission Already Under Strain

The May 2026 flyby carries extra weight because the mission nearly didn't happen at all. Psyche was originally slated for an August 2022 launch. Late delivery of guidance, navigation, and control software — combined with incomplete system verification and inadequate mission operations preparation — forced NASA to abandon that window [5].

The delay was not a simple scheduling hiccup. In November 2022, NASA convened an independent review board chaired by former NASA and Lockheed Martin executive Tom Young. The board's findings pointed to problems far deeper than a single software package [6].

"There is a large imbalance today between the workload and the available resources at JPL," Young stated in the review's findings [6]. The board identified an "unprecedented workload" across the laboratory's portfolio of flight projects, with technical expertise stretched thin across too many simultaneous missions. Engineers who spotted problems struggled to escalate them, while senior leadership lacked adequate visibility into project status [7].

The review also flagged the COVID-19 pandemic's impact on JPL's work culture. The "informal safety net" of hallway conversations, mentorship, and ad hoc problem-solving — long a hallmark of JPL's engineering culture — was "obliterated in COVID," as one assessment described it [8]. Hiring and retention suffered as commercial space companies and the U.S. Space Force offered higher salaries, particularly to software engineers [7].

JPL Director Laurie Leshin acknowledged the gravity of the situation but noted that the team made the right call: "They raised their hand and said, 'We're not ready and we shouldn't do this'" [8]. Corrective measures included implementing eight weeks of paid parental leave, establishing mandatory in-lab collaboration days, and requiring quarterly full-team meetings for remote workers [8].

The delay pushed Psyche's launch to October 13, 2023, when it successfully lifted off aboard a SpaceX Falcon Heavy rocket [4]. But the financial consequences cascaded. NASA's GAO assessment documented $159 million in cumulative cost overruns and 15 months of schedule delays [9]. The total lifecycle cost rose to approximately $1.2 billion, up from an earlier estimate of $960.6 million — a 20% increase [1].

The collateral damage extended beyond Psyche itself. NASA delayed the VERITAS mission to Venus indefinitely, stripping nearly all development funding to cover Psyche-related budget shortfalls. VERITAS's projected 2024 budget of $124 million was slashed to $1.5 million [10].

Gravity Assists: A Proven but Unforgiving Technique

Gravity assists have been a staple of interplanetary navigation since 1959, when the Soviet Luna 3 probe used one to photograph the far side of the Moon [11]. The technique became standard with Mariner 10 in the 1970s and was famously used by both Voyager probes to tour the outer solar system.

Mars-specific gravity assists are less common but have a strong track record. ESA's Rosetta spacecraft performed a Mars flyby at just 250 km altitude in February 2007 on its way to Comet 67P [11]. NASA's Europa Clipper conducted its own Mars gravity assist on March 1, 2025, en route to Jupiter [12]. Both maneuvers succeeded.

The overall success rate for Mars missions of all types — including orbiters, landers, and rovers — sits at roughly 50%, though that figure is heavily skewed by early-era failures from the 1960s and 1970s [13]. Modern gravity assists, executed with precision navigation and continuous tracking from the Deep Space Network, carry substantially lower risk. The margin of error is measured in kilometers, not the hundreds of kilometers that characterized early missions.

For Psyche, the planned closest approach of 4,500 km provides a reasonable buffer — considerably more cautious than Rosetta's 250-km Mars flyby, though the exact acceptable error margins have not been publicly specified by NASA [2].

The Scientific Instruments at Stake

Psyche carries three primary science instruments, each led by researchers at different institutions:

• A multispectral imager led by Jim Bell at Arizona State University, built in collaboration with Malin Space Science Systems, designed to map the asteroid's mineral composition and surface topography [14].
• A gamma-ray and neutron spectrometer led by David Lawrence at the Johns Hopkins Applied Physics Laboratory, which will determine the asteroid's elemental composition [14].
• A magnetometer — dual fluxgate instruments led by Ben Weiss at MIT with development support from Chris Russell at UCLA — that will search for evidence of an ancient magnetic field, which would strongly suggest the asteroid was once a molten planetary core [14].

The mission also carries a technology demonstration: NASA's Deep Space Optical Communications experiment, which tested laser-based data transmission during the cruise phase [14].

Principal Investigator Lindy Elkins-Tanton, based at Arizona State University, leads a team spanning more than a dozen universities and research institutions [14]. The Mars flyby itself serves double duty as a calibration opportunity. Sarah Bairstow, mission planning lead, noted: "This is our first opportunity in flight to calibrate Psyche's imager with something bigger than a few pixels" [15]. The team plans to capture thousands of observations of Mars using the multispectral imager, practicing techniques they will need upon arrival at the asteroid [2].

If the flyby were to fail and the spacecraft could not reach its target, the funded research programs tied to these instruments — spanning multiple universities, graduate student dissertations, and years of planned analysis — would lose their primary data source. NASA has not publicly described a contingency mission profile for a failed gravity assist.

Is 16 Psyche Really an Exposed Planetary Core?

The mission's entire scientific rationale rests on a hypothesis: that asteroid 16 Psyche is the exposed iron-nickel core of a protoplanet that was stripped of its outer layers by ancient collisions. Media coverage has frequently described the asteroid as worth "$10 quintillion" in raw metals — a figure that, while technically calculable from bulk iron and nickel prices, has no practical economic meaning given current space mining capabilities [16].

The exposed-core hypothesis, however, has come under sustained scientific scrutiny. The central problem is density. An intact iron-nickel core would have a bulk density of roughly 7.9 g/cm³. Psyche's measured bulk density is only 3.9 ± 0.3 g/cm³ — barely half what a solid metal body should weigh [16][17].

This discrepancy forces researchers into one of three explanations: the asteroid has very high porosity (around 50%), it contains substantial non-metallic components, or some combination of both [17]. A 2020 preflight assessment published in the Journal of Geophysical Research by Elkins-Tanton and colleagues estimated the asteroid contains between 30% and 60% metal by volume, with the remainder likely consisting of low-iron silicate rock and no more than 20% porosity [18].

Alternative models have been proposed. Laboratory work by David Cantillo and colleagues at the University of Arizona suggested that Psyche's spectral properties are best explained by a body that is approximately 82.5% metal, 7% low-iron pyroxene, and 10.5% carbonaceous chondrite — material likely delivered by impacting asteroids rather than originating from the body's own differentiation [19]. Other researchers have noted that CB chondrites (a rare class of meteorites) match both Psyche's density and spectral properties, which would imply the asteroid never differentiated into core and mantle layers at all [17].

Source: OpenAlex

Data as of Jan 1, 2026CSV

Academic interest in the asteroid has grown steadily, with over 1,000 peer-reviewed papers published on "asteroid Psyche" since 2011, peaking at 148 papers in 2025, according to OpenAlex data [20]. A 2026 paper in the Journal of Geophysical Research by Cambioni and colleagues modeled Psyche's formation through giant impacts, adding yet another possible origin story to the mix [21].

The Psyche mission was designed precisely to resolve this debate. But if the asteroid turns out to be a rubble pile of mixed composition rather than a pristine planetary core, the mission's flagship scientific narrative — and the justification for its cost — would need significant revision, even if the data collected remains scientifically valuable.

How Does Psyche's Price Tag Compare?

At $1.2 billion in lifecycle costs, Psyche is among the most expensive asteroid missions ever flown. OSIRIS-REx, which successfully returned a sample from asteroid Bennu in September 2023, cost approximately $1.16 billion over its 15-year history — and it brought material back to Earth [22]. Japan's Hayabusa2, which returned samples from asteroid Ryugu, accomplished its mission for roughly $150 million — an order of magnitude less, albeit with the benefit of Japan's lower labor costs and a less complex instrument suite [22].

Source: The Planetary Society / NASA

Data as of May 10, 2026CSV

NASA's Dawn mission, which orbited both Vesta and Ceres in the asteroid belt, cost approximately $730 million [1]. The Lucy mission to the Trojan asteroids has a lifecycle cost of about $981 million [1].

NASA evaluates flagship missions using criteria that include scientific priority (as set by the National Academies' Decadal Survey), technical readiness, and cost-risk assessments conducted by the GAO [9]. The agency does not publish a single metric comparing the "scientific return per dollar" of individual missions, making direct cost-effectiveness comparisons difficult. Critics of large flagship missions have long argued that funding could be more efficiently distributed across multiple smaller missions, though flagship missions often enable science that smaller spacecraft simply cannot perform — such as sustained orbital observations over 26 months, as Psyche plans [3].

Asteroid Mining: Legal Frontiers and Commercial Interest

The popular framing of Psyche as a "$10 quintillion asteroid" intersects with a real and evolving legal framework for space resource rights. The 2015 U.S. Commercial Space Launch Competitiveness Act explicitly grants U.S. citizens the right to "possess, own, transport, use, and sell" any asteroid resource they commercially recover [23]. The law was designed to sidestep the 1967 Outer Space Treaty's prohibition on claiming sovereignty over celestial bodies by drawing a distinction between sovereign territory and extracted resources [23].

The law does not, however, establish a regulatory process for licensing off-earth mining operations, planetary protection compliance, or oversight of extraction activities [24]. This regulatory gap has drawn attention from legal scholars, who note that while the right to extracted resources exists on paper, the mechanisms for exercising that right — and resolving disputes — remain undefined [24].

Several companies are actively pursuing asteroid mining capabilities. AstroForge, a startup focused on platinum-group metals, launched its first deep-space mission in February 2025 and is building what it describes as the first private landing on a body outside a planetary gravity well [25]. TransAstra is developing optical mining technology that uses concentrated sunlight to harvest water and materials from asteroids [25]. Earlier entrants — Planetary Resources (backed by Larry Page and Eric Schmidt) and Deep Space Industries — were acquired and pivoted away from mining by 2019 [25].

The asteroid mining market is projected to grow from $2.05 billion in 2025 to $5.42 billion by 2030, according to industry estimates [26].

Psyche's publicly released trajectory and compositional data do not, by themselves, create an exploitable legal precedent for private resource claims. The 2015 Act requires actual commercial recovery — physical possession of extracted material — not merely scientific characterization [23]. No entity can claim economic rights over asteroid 16 Psyche based on NASA's mission data alone. The asteroid's estimated metallic wealth remains a theoretical curiosity, not a legal asset.

What Happens on May 15

The Psyche operations team at JPL will monitor the flyby in near-real-time using the Deep Space Network. Multiple Mars-orbiting spacecraft — including NASA's Mars Reconnaissance Orbiter, Mars Odyssey, and ESA's Mars Express and ExoMars Trace Gas Orbiter — will provide complementary observations during the encounter [15].

The flyby is a one-shot event. Unlike orbital insertion maneuvers, which can sometimes be reattempted, a gravity assist at a specific planet occurs at a fixed point in the spacecraft's trajectory. If the approach geometry is wrong by too wide a margin, there is no second Mars to borrow from.

For a mission that has already survived a delayed launch, an institutional reckoning at one of NASA's premier laboratories, and a scientific hypothesis that grows more complicated with each new peer-reviewed paper, the Mars flyby is both a technical milestone and a symbolic one. It is the moment when Psyche stops being a spacecraft that almost didn't launch and starts being a mission that might answer one of planetary science's most basic questions: what lies at the center of a world.