NASA’s Psyche mission began eight weeks ago when it launched from the Kennedy Space Center. While it won’t reach its objective, the metal-rich asteroid Psyche, until 2029, the spacecraft has already travelled 26 million km (16 million miles.) During that time, it’s already had its share of success as it ticks off items on its checklist of tests.
Now, we have our first images from Psyche. And while they don’t show us anything about its eventual target, they give us a behind-the-scenes look at how complex spacecraft prepare themselves as they cruise toward their destinations.
When spacecraft like Psyche are launched, they’re ensconced in the nose of the rocket that carries them. All eyes are on the rocket and its successful launch. But once they separate from the rocket, they’re on their own and mission engineers monitor them carefully, powering up systems and checking scientific instruments according to a precise checklist.
Psyche has already streamed back some data and powered up scientific instruments. Now its twin cameras are operating, and we have our first images. They’re starfield images used to tell Psyche where it’s at in space. Psyche’s imaging system sent back a total of 68 images, all from the constellation Pisces. The image data will verify that the spacecraft is following thruster commands properly, allow mission personnel to verify that telemetry is working, and also allow images to be calibrated.
These images are like a newly-commissioned telescope’s first light.
Jim Bell is an astronomy professor at Arizona State University and the Psyche Imaging team lead. “These initial images are only a curtain-opener,” Bell said in a press release. “For the team that designed and operates this sophisticated instrument, first light is a thrill.”
Psyche will take opportunistic images of other bodies along its journey. These images also give mission operators a chance to test and verify the spacecraft’s imaging system in preparation for its rendezvous with the asteroid Psyche.
“We start checking out the cameras with star images like these, then in 2026, we’ll take test images of Mars during the spacecraft’s flyby,” Bell said. “And finally, in 2029, we’ll get our most exciting images yet – of our target asteroid Psyche. We look forward to sharing all of these visuals with the public.”
We don’t have any great images of Pysche. Most of the images are artist’s illustrations based on scientific data. They can only give us an indication of what it actually looks like.
All of our images of Psyche are illustrations based on scientific data. We’ll only get a good look at it when NASA’s Psyche finally rendezvous with the asteroid in 2029. Credit: Maxar/ASU/P. Rubin/NASA/JPL-Caltech
Spacecraft cameras often employ a system of filters to make them more versatile and scientifically productive. Psyche’s imaging system is a multispectral imager made of two identical cameras that provide redundancy in case there are any problems. The cameras have a system of filters that helps Psyche determine the nature of the asteroid’s topography, composition, and geology. Imager data will also build 3D maps of the asteroid’s surface.
Psyche’s multispectral imager during assembly and testing on Sept. 13, 2021, at Malin Space Science Systems in San Diego, California. Image Credit: NASA/JPL-Caltech/ASU/MSSS
“We don’t even know for sure just what Psyche is.”
As for the asteroid itself, it’s unique. In fact, it’s not just unique, it’s improbable. It may be the core from a planetesimal that was stripped of its outer layers through collision with another body. So this is a rare opportunity to examine something that nature has kindly excavated for us. According to one Psyche design document, the mission will give us a “Look inside the terrestrial planets, including Earth, by directly examining the interior of a differentiated body, which otherwise could not be seen.”
Psyche’s “first light” images make up this mosaic showing a starfield in the constellation Pisces. A version of the mosaic annotated with the names of the stars shown is at the bottom. Image Credit: NASA/JPL-Caltech/ASU
Psyche is a mystery. If it is a planetary core, it’s nothing like the rocky planets. Rocks on Earth, Mars, and Venus contain ample iron oxides. From a distance, Psyche doesn’t seem to contain many of these compounds. This suggests that its formation history is much different, but only a closer look can tell for sure. Scientists are keen to understand more clearly how our Solar System and its bodies formed, and outliers like Psyche are an important part of the bigger picture.
Much of what we know of Psyche’s surface comes from optical albedo and radar measurements. Image Credit: Shepard et al. 2022.
Once Psyche reaches its target, it’ll perform four progressively lower science orbits. Each orbit not only gives higher resolution science data, but they effectively “train” Psyche’s magnetometer. Its data will become more precise as Psyche gets closer. This is important because it’s up to the magnetometer to answer the huge question about the asteroid: is it the iron-rich core of a protoplanet or not?
The Psyche mission features four progressively lower science orbits. Each orbit’s final parameters cannot be defined until after the spacecraft arrives in the vicinity of Psyche when the gravity field can be measured in detail. Image Credit: Oh et al. 2019.
The imaging system is only the most recent successful test operation. The Psyche team has already fired the thrusters and tested part of the spacecraft’s gamma-ray and neutron spectrometer. They’ve also tested the new Deep Space Optical Communications (DSOC) system that uses lasers to send and receive data.
We have to wait until 2029 for all this work to pay off. At that time, Psyche will enter orbit around the asteroid and begin its nearly two-year mission to study it. While other missions have returned samples of asteroids, and while NASA’s Lucy spacecraft will visit a handful of asteroids in a single mission, none of those targets are like Psyche.
“This is a whole new kind of world,” said Lindy Elkins-Tanton, a professor of Earth and space exploration at Arizona State University and principal investigator for the Psyche mission. “We don’t even know for sure just what Psyche is,” she said. “We’re used to going to Mars, where we know a lot about it already—we have a lot of context. We just don’t have that for Psyche.”