Pedal to the metal: NASA’s Psyche launches to metallic asteroid
After an initial boost from SpaceX’s Falcon Heavy rocket, NASA’s Psyche mission has begun a six-year journey to metal-rich asteroid “16 Psyche,” a body that may be the exposed core of a protoplanet.
Liftoff occurred at 10:19 a.m. EDT (14:19 UTC) Oct. 13 from Launch Complex 39A at NASA’s Kennedy Space Center in Florida. It was SpaceX’s fourth Falcon Heavy launch of 2023 and the eighth overall for the rocket design. The Psyche spacecraft was deployed from the upper stage of the rocket just over an hour after liftoff to begin a journey of 2.2 billion miles (3.6 billion kilometers) to asteroid Psyche, located in the main asteroid belt between Mars and Jupiter.
“Congratulations to the Psyche team on a successful launch, the first journey to a metal-rich asteroid,” said NASA Administrator Bill Nelson in an agency news release. “The Psyche mission could provide humanity with new information about planet formation while testing technology that can be used on future NASA missions.”
The current mission trajectory has the Psyche spacecraft flying once around the solar system before intersecting with Mars in May 2026 for a gravity assist that will place it on a trajectory to intersect with 16 Psyche in August 2029.
From there, its primary science mission is expected to last about 26 months.
A metal-rich asteroid
Discovered by Italian astronomer Annibale de Gasparis in 1852, Psyche was the sixth asteroid to be discovered. The asteroid, which is named for the goddess of the soul in Greek mythology, orbits the Sun at a distance that ranges between 309 million miles (497 million kilometers) and 235 million miles (378 million kilometers). For comparison, the distance Earth orbits from the sun averages 93 million miles (150 million kilometers).
The “potato-shaped” asteroid measures some 173 miles (280 kilometers) by 144 miles (323 kilometers). According to NASA, even though 16 Psyche is very dense, its gravitational pull is still small. The agency said lifting a car would feel like lifting a large dog.
Because of its density, NASA said scientists believe the asteroid may consist of a large amount of metal from the remnant core of a “planetesimal” and may be a survivor of multiple violent collisions when the solar system was still forming several billion years ago.
NASA said existing radar observations from Earth suggest that the asteroid is composed of a mixture of rock and metal, with metal being between 30% to 60% of its volume. Combined with optical observations, there appears to be evidence of two craterlike depressions, which the agency said suggests significant variation in the metal content across its surface.
However, the agency said there are still contradictions in the data and until the spacecraft sees the asteroid up close, we won’t don’t know for certain what it actually looks like.
The Psyche mission
The Psyche mission was selected by NASA as part of NASA’s Discovery Program in 2017 and is managed by NASA’s Jet Propulsion Laboratory. The original plan was to launch between August and October 2022, which would have allowed for a more favorable trajectory and an arrival in January 2026.
However, late delivery of testing equipment and flight software would not allow for enough time to make the 2022 window. Launching in 2023 meant adding several years to its cruise.
According to Arizona State University, which is where the mission’s Principal Investigator Lindy Elkins-Tanton is based, the total cost for the Psyche mission is about $850 million, which includes development, operations and science, but not launch costs.
In 2020, NASA awarded SpaceX a $117 million contract to launch the Psyche spacecraft atop the company’s Falcon Heavy rocket.
The main body of the Psyche spacecraft is 16.1 feet (4.9 meters) tall, 7.1 feet (2.2 meters) wide and 7.8 feet (2.4 meters) deep, according to NASA. With its two solar arrays deployed the vehicle would cover an area roughly the size of a tennis court and produce about 21 kilowatts of power while near Earth and between 2.3 and 3.4 kilowatts while orbiting the asteroid.
Overall, the spacecraft has a mass of about 6,056 pounds (2,747 kilograms) and uses solar electric propulsion. The vehicle has four Hall-effect thrusters that use charged ions of inert xenon gas to create thrust. NASA said only one will be used at a time to produce up to 240 millinewtons of thrust, which the agency said is about the force you would feel while holding the weight of one AA battery.
Science on Psyche
Psyche sports three dedicated science instruments for its primary mission. It has a multispectral imager to photograph the surface of the asteroid in visible and near-infrared. There is a gamma-ray and neutron spectrometer, which will help scientists determine the chemical elements that make up its surface.
Finally, a magnetometer will be used to look for evidence 16 Psyche has or had a magnetic field, which would support the hypothesis that the body is a remnant planetesimal core.
The spacecraft’s X-band radio communications system will also be used to perform gravity science, which NASA says will help scientists better understand the asteroid’s rotation, mass, gravity field as well as clues about the interior structure of the body.
While not part of the primary mission, Psyche carries a technology demonstrator called Deep Space Optical Communications, or DSOC.
DSOC is expected to mainly be used during the first part of the mission, the journey toward the asteroid. The experiment’s objective is to test using a near-infrared laser to send high-bandwidth data from the spacecraft to Earth. It would be the first time such a technology will have been used by NASA at distances well beyond the Moon.
While the time it takes for any signal to reach Earth from distant locations will always be limited to the speed of light, laser communication technology enables higher-bandwidth transmissions, allowing for more information to be sent at the same time while not requiring more or larger hardware.
NASA said DSOC relay demonstrations are only intended for the first two years of the spacecraft’s cruise, but the technology could be used for future human and robotic spacecraft.
“Launching with Psyche is an ideal platform to demonstrate NASA’s optical communications goal to get high-bandwidth data into deep space,” Dr. Prasun Desai, acting associate administrator for the Space Technology Mission Directorate at NASA Headquarters, said in an agency news release. “It’s exciting to know that, in a few short weeks, Deep Space Optical Communications will begin sending data back to Earth to test this critical capability for the future of space exploration. The insights we learn will help us advance these innovative new technologies and, ultimately, pursue bolder goals in space.”
Video courtesy of NASA
Derek Richardson has a degree in mass media, with an emphasis in contemporary journalism, from Washburn University in Topeka, Kansas. While at Washburn, he was the managing editor of the student run newspaper, the Washburn Review. He also has a website about human spaceflight called Orbital Velocity. You can find him on twitter @TheSpaceWriter.