NASA’s Psyche spacecraft successfully flew close to Mars by using the planet’s gravity to gain speed and change course towards the asteroid Psyche. On May 15, the spacecraft passed within 2,864 miles (4,609 kilometers) of the surface of Mars, receiving significant gravity assistance without using additional onboard fuel.
This maneuver sends Psyche on a direct route to a target in the asteroid belt between Mars and Jupiter. After the flyby, engineers confirmed that the spacecraft was exactly where it needed to be by analyzing radio communications between Psyche and NASA’s Deep Space Network (DSN), the agency’s worldwide communications system for deep space missions.
“While we were confident in our calculations and flight planning, it was still exciting to monitor the DSN’s Doppler signal in real time during the flyby,” said Dong Han, Psyche’s navigation director at NASA’s Jet Propulsion Laboratory in Southern California. “We confirmed that Mars gave the spacecraft an acceleration of 1,000 miles per hour, shifting its orbital plane about 1 degree relative to the Sun. We are now on track to reach the asteroid Psyche in summer 2029.”
Psyche captures rare view of Mars’ crescent moon
The Mars encounter also gave the mission team the opportunity to fully test Psyche’s scientific instruments before the spacecraft arrived at the asteroid. In the days leading up to the flyby and closest approach, engineers turned on the spacecraft’s imager, magnetometer, and gamma-ray and neutron spectrometers.
As Psyche approached Mars, the angle between the spacecraft, Mars, and the sun made Mars appear like a narrow crescent moon. Images taken by the spacecraft’s multispectral camera show that the crescent moon is more spread out around the planet than expected. Scientists say sunlight scattering through Mars’ dusty atmosphere likely caused the effect. Near its closest approach, the spacecraft rapidly imaged the surface of Mars as it entered daylight from the night side of Mars.
“We captured thousands of images during the approach to Mars and its surface and atmosphere,” said Jim Bell, Arizona State University (ASU) Tempe’s Psych Imaging Instrument Leader. “As the spacecraft continues its journey after the flyby, we will continue to take calibration images of Mars as it recedes into the distance for the remainder of the moon.”
Bell also leads the Mastcam-Z imaging survey for NASA’s Perseverance spacecraft mission. Several additional Mars missions contributed supporting observations during the flyby, including NASA’s Mars Reconnaissance Orbiter, 2001 Mars Odyssey Orbiter, and Curiosity rover, as well as ESA’s Mars Express and ExoMars Trace Gas Orbiters.
Inspection equipment before arriving at the asteroid Psyche
The flyby also allowed scientists to collect valuable calibration data from Psyche’s other instruments. Early measurements from the spacecraft’s magnetometer may have detected Mars’ bow shock, a region where the solar wind interacts with Mars’ magnetic environment.
At the same time, the gamma-ray and neutron spectrometer team collected measurements that can be compared to decades of existing Mars data.
With Mars behind it, Psyche resumes using its solar electric propulsion system and heads toward the asteroid belt. The spacecraft is scheduled to arrive at the asteroid Psyche in August 2029.
Scientists believe that Psyche may be the exposed partial core of an ancient planetesimal, one of the building blocks that formed planets early in the solar system’s history. The asteroid is approximately 173 miles (280 kilometers) in diameter at its widest point.
Once there, the spacecraft will orbit Psyche at several different altitudes, mapping the surface and collecting scientific data. If this asteroid truly represents the metallic interior of an early world, it could offer researchers a rare opportunity to study materials similar to those found deep within rocky planets like Earth.
“We’ve been waiting for a Mars approach for years, and now it’s done. We want to thank Mars for providing critical gravitational pull for our spacecraft deeper into the solar system,” said Lindy Elkins Tanton, principal investigator for Psych Research at the University of California, Berkeley. “To the asteroid Psyche!”
About NASA’s Psych Mission
The Psyche mission is led by ASU. NASA’s Jet Propulsion Laboratory (JPL), a division of the California Institute of Technology in Pasadena, manages mission operations, engineering, testing, and systems integration.
The spacecraft chassis for Psyche’s high-power solar-powered propulsion system was provided by Intuitive Machines of Palo Alto, California. ASU is overseeing operations of the spacecraft’s imaging equipment in partnership with Marine Space Science Systems of San Diego, which helped design, manufacture and test the camera.
Psyche is the 14th mission selected for NASA’s Discovery Program, managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama. NASA’s Launch Services Program at Kennedy Space Center in Florida managed launch services for this mission.
