NASA’s Psyche spacecraft successfully completed a close flyby of Mars, using the planet’s gravity to gain speed and refine its route to asteroid Psyche. The maneuver also delivered valuable scientific observations as mission teams prepare for the spacecraft’s arrival at the metal-rich asteroid in 2029.
On May 15, NASA’s Psyche spacecraft passed Mars and used the planet’s gravitational pull to increase its velocity and make a precise adjustment to its trajectory. The Mars gravity assist placed Psyche on the path required to reach its destination in the main asteroid belt between Mars and Jupiter.
The flyby also gave scientists an important opportunity to test Psyche’s instruments near a well-studied planet. Mars served as a practice target for the cameras, magnetometer, and gamma-ray and neutron spectrometer that will eventually investigate asteroid Psyche. Initial data showed that all instruments performed as expected, matched established observations of Mars, and captured new information from the spacecraft’s unique vantage point.
“The mission’s imager, magnetometer, and gamma-ray and neutron spectrometer teams worked overtime to make full use of this planetary encounter, and all instruments delivered great results,” said Lindy Elkins-Tanton, principal investigator for Psyche at the University of California, Berkeley. “We didn’t anticipate big discoveries, given how extensively the planet has been studied, but we did complement Mars science with the data we collected through Psyche’s unique perspective.”
Psyche Detects Neutrons From Mars
The Mars flyby provided an important test for Psyche’s gamma-ray and neutron spectrometer. Once the spacecraft reaches asteroid Psyche, this instrument will help scientists identify the chemical elements found in the asteroid’s surface material.
When high-energy cosmic rays strike a planetary surface, they transfer energy to elements in the soil and rocks. Those elements can then emit neutrons and gamma rays at specific energy levels. By measuring these signals and comparing them with known elemental signatures, researchers can determine the composition of a planetary body.
Psyche passed Mars at an altitude of 2,864 miles (4,609 kilometers). The spacecraft was too far away to detect gamma rays from the planet, but mission scientists expected the instrument might still measure neutrons escaping from Mars’ surface and atmosphere.
“Around the time of Mars closest approach, the neutron spectrometer detected a count-rate enhancement close to what we anticipated. It was very gratifying to see,” said David Lawrence, the science lead for Psyche’s spectrometer at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland. “As expected, we didn’t detect gamma rays from Mars, but we put the instrument through its paces, and it performed excellently.”
Measuring Mars’ Magnetic Environment
NASA’s Psyche magnetometer has been operating since the spacecraft launched in 2023. Its primary mission is to study the magnetic field of asteroid Psyche and help researchers determine whether the object could be the exposed metallic core of a planetesimal, an early building block of a rocky planet.
During its journey through space, the magnetometer has continuously monitored the magnetic field carried by the solar wind. It has also recorded disturbances created by occasional coronal mass ejections passing over the spacecraft. The Mars flyby marked the first time the instrument measured the magnetic signature of another celestial body.
“As the spacecraft passed close to Mars, the magnetometer saw an intense uptick in magnetic field corresponding to the bow shock region, where the solar wind slams into the planet’s magnetic field,” said Ben Weiss, Psyche’s deputy principal investigator and the magnetometry investigation lead at Massachusetts Institute of Technology in Cambridge. “This flyby calibration effort validated the instrument’s performance under dynamic conditions while also revealing the fascinating physics of planetary magnetism.”
Rare Images of the Red Planet
Psyche’s multispectral imager began capturing views of Mars in early May and continued observing the Red Planet during and after the flyby. The imaging system includes two identical cameras designed to photograph asteroid Psyche across multiple wavelengths of light.
Because the spacecraft approached Mars at a high phase angle, the planet initially appeared as a narrow, bright crescent. Sunlight scattering through the Martian atmosphere created the striking appearance.
As Psyche moved closer, its cameras recorded surface features including wind-shaped craters, the south polar ice cap, and the enormous double-ringed Huygens crater. Scientists combined the monthlong sequence into a time-lapse video showing the spacecraft’s approach to and departure from Mars. [See link to video after the end of the article.]
“The imager performed brilliantly, delivering some rarely seen views of the Red Planet,” said Jim Bell, the Psyche imager instrument lead at Arizona State University in Tempe. “Besides the obvious beauty of the photos, we were also able to fully test its calibration and sensitivity to scattered light, including picking out the Martian moons Phobos and Deimos from very far away as a part of a practice for the satellite search that we’ll use at the asteroid Psyche to look for any moonlets there.”
The distant detection of Mars’ moons, Phobos and Deimos, served as a rehearsal for the mission’s future search for small moons orbiting asteroid Psyche.
Comparing Psyche’s Mars Images With Other Missions
To evaluate and calibrate the spacecraft’s imaging system, researchers are comparing Psyche’s Mars flyby images with observations collected by other spacecraft and rovers.
These sources include NASA’s Mars Reconnaissance Orbiter, 2001 Mars Odyssey orbiter, and Curiosity and Perseverance rovers. The team is also using data from the European Space Agency’s Mars Express and ExoMars Trace Gas Orbiter, as well as the United Arab Emirates Mars Mission’s Hope Orbiter.
Comparing the observations will help scientists better understand the performance of Psyche’s cameras before the spacecraft begins studying its far less familiar asteroid target.
On Course for Asteroid Psyche in 2029
After completing the successful Mars gravity assist, NASA’s Psyche spacecraft is now traveling toward asteroid Psyche, which orbits in the main asteroid belt between Mars and Jupiter.
“This gravity assist was years in the making, and the navigation team nailed it — Psyche flew by Mars on exactly the trajectory we needed to set us on a path to rendezvous with the asteroid in the summer of 2029,” said Bob Mase, Psyche’s project manager at NASA’s Jet Propulsion Laboratory in Southern California. “The spacecraft is in great shape, and we’re on schedule to resume sustained thrusting with the solar-electric propulsion system later this fall.”
Source: www.sciencedaily.com