SerpApi.Org
The American probe Psyche grazed Mars on May 15, 2026, before resuming its course toward the metallic asteroid that bears the same name. This detour around the red planet primarily allowed the spacecraft's trajectory to be modified without consuming fuel.
At its closest, Psyche passed 4,609 km above the Martian surface. Mars's gravity then accelerated the probe by approximately 1,600 km/h. It also tilted its orbital plane by about 1 degree relative to the Sun, a necessary correction to reach its target in the main asteroid belt.
This technique is called gravitational assist. A probe exchanges a tiny fraction of energy with a moving planet when it passes nearby. The result depends on the trajectory chosen with great precision. In Psyche's case, Mars acted as a natural relay to send it toward a more favorable orbit.
The views of Mars are therefore not merely a visual bonus. During the approach, the probe's multispectral imager followed the planet's crescent, which gradually grew larger in its field of view. At closest approach, Mars became too large for it.
Psyche arrived facing a poorly lit portion of Mars from its position. The planet thus appears as a thin crescent, like the Moon near the new moon. The observed light comes from the Sun reflected by the Martian ground and scattered by atmospheric dust.
The flyby also served as a dress rehearsal for the mission's instruments. Teams were able to verify their operation on a known planet and prepare for the scientific operations that will be conducted near the asteroid. Radio signals received by the Deep Space Network later confirmed that the obtained trajectory matched predictions.
Psyche was launched in October 2023 to study asteroid 16 Psyche, located between Mars and Jupiter. This object is rich in metals, but its exact composition remains to be determined. It could preserve clues about the materials present in the early small bodies that participated in planet formation.
The probe is scheduled to arrive near the asteroid in the summer of 2029, before beginning its detailed study in August. It will photograph it, map its surface, and measure its physical properties. The Mars flyby thus marked a discreet but decisive step.
