The Psyche spacecraft passed within 4,500 kilometers of Mars to receive a gravity boost. The pass was also used to calibrate cameras and scientific instruments in preparation for its arrival at the asteroid Psyche in 2029.
NASA's Psyche spacecraft made a close flyby of Mars on May 15, 2026, as part of its long journey to the metallic asteroid Psyche. According to NASA's Jet Propulsion Laboratory (JPL), the spacecraft will pass within about 2,800 miles (4,500 km) of the Martian surface, traveling at about 12,300 miles (19,848 km) per hour. The primary goal of the maneuver is to use Mars' gravity to accelerate the spacecraft and change its trajectory so that it continues on the right path toward the asteroid belt. (NASA Jet Propulsion Laboratory (JPL))
Psyche launched on October 13, 2023, and is making its way to one of the most intriguing bodies in the solar system: an asteroid that is believed to contain a high proportion of metals, and is located in the main asteroid belt between Mars and Jupiter. NASA notes that the spacecraft is scheduled to begin studying the asteroid in August 2029. The mission's goal is to better understand metallic bodies, and perhaps gain an indirect glimpse into the processes that occurred in the cores of planetary bodies in the early solar system. (NASA Science)
Gravity maneuver instead of fuel consumption
The Mars flyby is an example of a gravity maneuver, or “gravity trap.” Instead of wasting a large amount of fuel, the spacecraft uses the planet’s motion and gravitational field to change its speed and direction. In the case of Psyche, this is especially important because the spacecraft relies on solar-electric propulsion and xenon gas, a highly efficient but gradual system. The Mars maneuver allows it to conserve propellant while still continuing on the necessary trajectory to its destination.
In preparation for the transit, the mission team performed a trajectory correction maneuver on February 23, 2026. During this time, the engines were operated for 12 hours, in order to fine-tune the path to Mars. NASA explains that the spacecraft is on the exact trajectory required for the transit, and that the flight computer was pre-programmed for operations to be carried out during the month of May.
In addition to the engineering maneuver, the Mars flyby provides the mission team with a rare opportunity to test the science instruments under real-world flight conditions. Psyche's multispectral imaging camera will take thousands of observations of Mars, and the data will help calibrate the system for the asteroid's arrival. The instruments will also be able to practice observation methods that will later be used to search for small moons or nearby structures around Psyche.
Mars as a thin crescent
Even before the upcoming flyby, the spacecraft began transmitting images of Mars. On May 3, 2026, Psyche photographed the planet from a distance of about 4.8 million kilometers. Mars appears in the image as a thin crescent because the spacecraft is approaching it from a high angle of incidence, meaning mainly from its night side. According to NASA, the light reflected from Mars and the light scattered by atmospheric dust create a bright, elongated crescent around the planet.
This geometry is of particular interest to the imaging team. Before the transit, Mars will appear as a narrow crescent, and after the transit, it will appear fuller. Switching between the two angles will allow us to test how the cameras cope with brightness, contrast, atmospheric scattering, and changing exposure conditions. According to NASA, the images are primarily intended to calibrate the cameras and test their performance ahead of the asteroid Psyche approach in 2029.
Mission scientists are also interested in testing whether Mars has a faint dust ring. Such dust particles may be formed by tiny impacts on Mars' moons, Phobos and Deimos. If the angle of illumination is right, some of the dust may appear in the processed images. Even if such a finding is not made, the very attempt will contribute to practicing delicate observation methods that will be needed later around the asteroid.
On the way to a metallic world
The Psyche mission is designed to explore a body very different from most known asteroids. While many asteroids are made mostly of rock or ice, Psyche is thought to be an asteroid with an exceptionally high metal content. One possibility is that it represents the remnant of a planetesimal core, an ancient body that was part of the planet-building process. Studying it could help us understand how metallic cores formed in rocky bodies, including Earth, even though we don't have direct access to Earth's core.
Once it reaches its destination, the spacecraft is scheduled to enter orbit around the asteroid and study it for about two years. It will photograph the surface, map it, measure magnetic fields, and collect data on its composition. So the flyby of Mars is not only a milestone in the orbit, but also an important rehearsal for the science mission itself.
The close pass by Mars is expected to be felt primarily in control rooms, via the spacecraft's radio signals. Mission teams will monitor Doppler shifts in signals sent over NASA's Deep Space Network, confirming that the velocity and trajectory have been updated as planned. Other NASA and European Space Agency missions operating at Mars are expected to assist in observations and data comparisons, including Mars orbiters and surface rovers.
Quick FAQ
What is the purpose of Psyche's passage near Mars??
The goal is to use Mars' gravity to accelerate the spacecraft and change its trajectory toward the asteroid Psyche.
When will the spacecraft reach asteroid Psyche??
NASA plans for the spacecraft to begin exploring the asteroid in August 2029.
Why the asteroid Psyche is interesting?
It is considered a metal-rich asteroid, and perhaps a remnant of an ancient body that could provide evidence of the formation of planetary cores.
Is the Mars flyby also a scientific mission??
Yes, but that's not its primary purpose. During the transit, NASA will test and calibrate cameras and scientific instruments, and collect data about Mars.
