NASA's Psyche Spacecraft Prepares for May 15 Mars Flyby, Using the Planet's Gravity to Save Propellant on the Way to a Metal Asteroid
Psyche will pass 4,500 kilometers above Mars on May 15 at 12,333 mph, harnessing the planet's gravity to redirect itself toward the metal-rich asteroid Psyche and calibrate its imager, magnetometer, and gamma-ray spectrometer.
Overview
NASA’s Psyche spacecraft is on course for a close flyby of Mars on Friday, May 15, 2026, passing 2,800 miles (4,500 kilometers) above the Martian surface at 12,333 mph (19,848 kph), according to NASA Science. The encounter is a propellant-saving gravity assist designed to bend the probe’s trajectory toward its destination, the metal-rich asteroid Psyche, as NASA’s Jet Propulsion Laboratory explains.
What We Know
Psyche launched on Oct. 13, 2023 aboard a SpaceX Falcon Heavy rocket, per JPL, and uses a solar-electric propulsion system powered by the inert gas xenon. Letting Mars’s gravity do part of the work means the spacecraft burns less of that xenon on its way out, as JPL describes.
The flight team has already locked in the maneuver. “We are now exactly on target for the flyby, and we’ve programmed the flight computer with everything that the spacecraft will do throughout May,” Sarah Bairstow, the mission’s planning lead at JPL, said in NASA’s announcement. Principal investigator Lindy Elkins-Tanton, based at UC Berkeley, framed the encounter in plain terms: “The only reason for this flyby is to get a little help from Mars to speed us up and tilt our trajectory in the direction of the asteroid Psyche,” she said in the same release.
The team is also using the flyby as a working calibration of the science payload. Psyche carries a multispectral imager, a magnetometer, and a gamma-ray and neutron spectrometer, according to NASA Science. It is the mission’s first chance in flight to point the imager at something larger than a few pixels across, the same blog post notes. Jim Bell, the imager instrument lead at Arizona State University, said in NASA’s release: “The thin crescent on approach and the nearly ‘full Mars’ view after we fly past create opportunities for both great calibration observations.” During the encounter the magnetometer may watch Mars’s magnetic field interacting with charged particles from the Sun, while the gamma-ray and neutron spectrometer will track changes in cosmic rays as the spacecraft passes the planet, per NASA Science.
Approach imagery is already coming down. A panchromatic snapshot taken on May 3, 2026, from roughly 3 million miles (4.8 million kilometers) away, used a 2-millisecond exposure through the imager’s broadband filter, JPL reported. Mission specialists noted that seasonal clouds and hazes in some regions of the Martian disk may be blocking atmospheric dust from scattering sunlight the way it normally does, JPL added.
The spacecraft will also use the flyby for a navigation drill. Psyche will run satellite-search observations across the Martian sky as a rehearsal for the later hunt for possible moonlets around the asteroid itself, SpaceDaily reported.
The Destination
The asteroid Psyche sits in the outer part of the main asteroid belt and measures about 173 miles (280 kilometers) at its widest point, according to JPL’s mission press kit. It is one of the largest metal-rich bodies that mission scientists have been able to target with a dedicated orbiter, and the spacecraft is named after it. After a six-year journey covering about 2.2 billion miles (3.6 billion kilometers), Psyche is expected to start orbiting the asteroid in August 2029 and stay there for at least 26 months, per the same JPL press kit. ScienceDaily likewise places the arrival in 2029.
What We Don’t Know
Neither NASA nor JPL has published the calibrated science return expected from the Mars encounter beyond the team’s stated goals of imager calibration, magnetic-field observation, and cosmic-ray monitoring. The exact yield of the moonlet-search rehearsal and any atmospheric findings from the imager will depend on data downlinked after the flyby. The pre-flyby image and the science team’s hypothesis about seasonal clouds and hazes are preliminary; JPL described the explanation as a hypothesis rather than a confirmed result.
The Mars flyby is one step in a long trajectory that still has more than three years to run before orbit insertion at the asteroid, and the propulsion, navigation, and instrument performance during the encounter will inform how the team plans the asteroid arrival in 2029, per NASA Science.