NASA's Psyche spacecraft conducted a Mars gravity assist on May 15, swooping within 2,864 miles of the surface to gain a 1,000-mph velocity boost toward its destination asteroid. The encounter, captured in a new time-lapse video stitched from May images, served dual purposes: redirecting Psyche onto the correct trajectory for its 2029 asteroid arrival and validating all three of the spacecraft's science instruments before the main mission. The flyby represents years of navigation planning that put the probe exactly where it needed to be, according to project manager Bob Mase at JPL.
The video shows Mars expanding from a thin crescent -- initially illuminated at just 4 percent as Psyche approached from a steep angle relative to the sun -- into a full disk revealing craters, the double-ringed Huygens crater, and the south polar ice cap before fading into the spacecraft's rearview. Psyche's instruments performed as expected during closest approach: the gamma-ray and neutron spectrometer detected the predicted surge of escaping neutrons confirming its operational readiness, the magnetometer recorded its first magnetic signature from a planetary body since launch, and the multispectral cameras passed calibration tests while capturing Phobos and Deimos for practice ahead of searching for moonlets around asteroid Psyche.
The Mars data complements existing planetary science while serving primarily as a checkout run for instruments designed to study the metal-rich asteroid. Principal investigator Lindy Elkins-Tanton noted that no major discoveries were expected given how extensively Mars has been studied, but Psyche's unique vantage point added value to the record. Spotting Mars' moons gave the imaging team a dry run for detecting small bodies in orbit around the target asteroid.
With calibration complete and instruments fully vetted, Psyche remains on course for its summer 2029 rendezvous with the metal asteroid. The spacecraft will resume sustained solar-electric propulsion thrusting later this fall, Mase said, keeping the mission on schedule.