At roughly 12,333 miles per hour, NASA’s Psyche spacecraft will skim about 2,800 miles above the Martian surface on Friday, May 15, 2026, threading a gravitational needle that mission planners have been refining since before the probe left Earth. The flyby is not a scenic detour. It is the single most consequential event between launch and arrival: a fuel-free slingshot that, if executed correctly, will bend Psyche’s trajectory and lock it onto a course for a late July 2029 rendezvous with asteroid 16 Psyche, a metal-rich body in the asteroid belt that some back-of-the-envelope estimates have valued at $700 quintillion.
What happens during the flyby
The encounter will unfold quickly. As Psyche approaches Mars, the planet’s gravity will tug the spacecraft inward, accelerating it and curving its path like a ball rolling along the inside of a bowl. At closest approach, roughly 4,500 kilometers (2,800 miles) above the surface, the probe will be moving at about 19,848 kph (12,333 mph), according to a JPL mission update. Within hours, Mars will have redirected Psyche’s flight path and added velocity, all without burning a drop of xenon propellant.
Gravity assists are a proven technique. NASA has used them on missions from Voyager to Cassini to the Parker Solar Probe. But each one is unique, and the geometry must be precise. Engineers at the Jet Propulsion Laboratory uploaded the final trajectory-correction commands in the days before the flyby, fine-tuning the spacecraft’s approach angle to fractions of a degree. A successful pass locks in the 2029 arrival timeline. A significant deviation could force controllers to burn precious xenon to compensate, potentially delaying the mission or, in an extreme case, putting the asteroid encounter at risk.
The spacecraft and its mission
Psyche launched on October 13, 2023, aboard a SpaceX Falcon Heavy from Kennedy Space Center. The mission is managed by JPL in partnership with Arizona State University, Maxar Technologies, and SpaceX, as detailed in the official mission press kit.
The probe is powered by solar-electric propulsion: Hall-effect thrusters that ionize xenon gas and expel it at high speed, producing a gentle but continuous push. Over months of firing, that low thrust accumulates into significant velocity changes. The Mars gravity assist complements the approach. Where the thrusters slowly build speed over long arcs, the flyby delivers a sharp, fuel-free course correction in a matter of hours.
During the cruise phase, engineers did encounter a propulsion-system anomaly involving the xenon feed system. The team resolved it by switching to a backup propellant line, and the spacecraft resumed full thruster operations, according to updates on NASA’s Psyche mission page. No further anomalies have been publicly reported since the fix.
Psyche also carries the Deep Space Optical Communications (DSOC) technology demonstration, a laser-based system that has already set records for high-rate data transmission across interplanetary distances during the cruise phase. Whether DSOC sessions will pause around closest approach to simplify the spacecraft’s attitude control, or whether engineers plan to treat the flyby as a stress test for the laser’s pointing system, has not been detailed in public materials.
What scientists hope to find at asteroid 16 Psyche
The destination is a roughly potato-shaped body about 173 miles across, orbiting in the main asteroid belt between Mars and Jupiter. Scientists believe 16 Psyche may be the exposed iron-nickel core of a protoplanet that was stripped of its rocky outer layers by violent collisions billions of years ago. If that hypothesis holds, the asteroid would offer a direct window into the kind of metallic interior that lies thousands of miles beneath Earth’s surface, forever out of reach of any drill.
To test that idea, the spacecraft carries four instrument suites. A magnetometer will search for a remnant magnetic field, which would confirm the asteroid once generated its own dynamo. A gamma-ray and neutron spectrometer will map the elemental makeup of the surface. A multispectral imager will photograph terrain features across multiple wavelengths. And a gravity science investigation, conducted through the spacecraft’s radio telecommunications system, will chart the asteroid’s internal mass distribution by tracking subtle shifts in the signal between Psyche and Earth.
Orbit insertion is expected in late July 2029, with the prime science mission beginning in August 2029, according to NASA’s science overview.
About that $700 quintillion price tag
The headline number attached to asteroid 16 Psyche did not come from NASA. It originated from media estimates that multiplied the asteroid’s presumed metal content by Earth commodity prices for iron and nickel. Scientists on the mission have pushed back on the figure, noting that no technology exists to mine the asteroid, no infrastructure could return that volume of material to Earth, and flooding global markets with it would collapse the very prices used to generate the estimate. The real value of the mission is scientific: understanding how rocky planets form and differentiate, not appraising an extraterrestrial ore deposit.
How to follow the Mars flyby on May 15, 2026
Friday’s flyby is optimized for navigation, not spectacle, so do not expect sweeping Martian panoramas. JPL has indicated the multispectral imager may capture some images of Mars during the encounter, but the priority is nailing the trajectory. Confirmation that the gravity assist succeeded will come from post-flyby tracking data, typically shared through JPL’s mission blog within days. Readers can also check NASA’s Psyche mission page for status updates as they are posted.
If all goes as planned, Psyche will spend the next three years cruising deeper into the asteroid belt under the quiet thrust of its ion engines. By the summer of 2029, it will slow into orbit around a world made almost entirely of metal, a place no spacecraft has ever visited. The data it sends back could reshape what planetary scientists understand about the hidden cores of rocky worlds, including our own.
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*This article was researched with the help of AI, with human editors creating the final content.
