NASA, SpaceX launch Psyche mission to metallic asteroid

by Haygen Warren

NASA and SpaceX teams launched the agency’s Psyche mission to metallic asteroid 16 Psyche from Florida on Friday, Oct. 13. Psyche launched atop a SpaceX Falcon Heavy rocket from Launch Complex 39A (LC-39A) at the Kennedy Space Center in Cape Canaveral, Florida. Launch occurred at 10:19 AM EDT (14:19 UTC).

Psyche is the first mission to ever visit and extensively study a metallic asteroid. 16 Psyche is thought to have once been the core of forming planetesimal back when the solar system was first forming. If this prediction is true, 16 Psyche could provide planetary scientists with incredible amounts of information and insight into how planets form and what the cores of planets like Earth, Mars, and Mercury look like.

Psyche’s history

Psyche is the 14th mission in NASA’s Discovery Program; a program that supports solar system exploration missions that are lower in cost than NASA’s New Frontier and Flagship programs and that focus on achieving one specific scientific goal rather than a more general purpose or investigation.

Psyche’s mission plans and goals were submitted to NASA in February 2015. Later that year, in September, Psyche was one of five finalists selected for further concept development, receiving an additional $3 million. Finally, on Jan. 4, 2017, Psyche was selected alongside the Lucy mission by NASA as the agency’s 14th and 13th Discovery missions, respectively.

In May 2017, Psyche teams announced they were targeting July 2022 for the launch of Psyche. When initially selected, teams set the mission’s launch date for 2023, but the date was moved to July 2022 to target a more efficient launch and cruise trajectory. In August 2020, NASA announced it had selected SpaceX’s Falcon Heavy rocket to launch the mission.

As Psyche’s first launch window in July 2022 approached, NASA and Psyche teams noted that the late delivery of flight software, testing hardware, and other components needed for the spacecraft did not allow for enough time to fully complete testing and the shipment of the spacecraft. Thus, the teams elected to delay the launch past the July 2022 launch window, and instead opted to launch the spacecraft during either the 2023 or 2024 launch windows. In October 2022,  NASA and Psyche teams announced they were targeting the 2023 launch window, which opened in October 2023 and would see the spacecraft arriving at the asteroid in August 2029.

Finally, on April 18, 2023, NASA’s Jet Propulsion Laboratory (JPL) set the launch date for Oct. 5, 2023. Psyche was then shipped to the Cape and prepared for integration with its Falcon Heavy rocket. However, an issue with the spacecraft’s cold gas thrusters led to the launch being delayed by a week, with a new launch date of Oct. 12. Unfavorable weather conditions then led to a scrub for Oct. 12, and the launch was pushed back one day to Oct. 13.

The Psyche spacecraft and mission

The Psyche spacecraft is designed to perform a 21-month primary science mission at Psyche, which will take place after the spacecraft’s near six-year coast phase through the solar system. During the coast phase, Psyche will complete a gravity assist maneuver at Mars to help increase the spacecraft’s velocity and trajectory to 16 Psyche.

Psyche’s spacecraft bus is the Space Systems Loral 1300 platform, with JPL handling the construction and addition of all command and data handling, telecom subsystems, and flight software. The spacecraft will use four SPT-140 Hall-effect ion thrusters, which utilize the electricity produced by the spacecraft’s solar panels to generate thrust. The thrusters will nominally operate at 4.5 kW while also being operated at approximately 900 watts during long periods of time. The use of these thrusters on Psyche will make Psyche the first mission to ever use Hall Effect ion thrusters outside of lunar orbit.

Diagram showing the Psyche spacecraft. (Credit: Hannah Sweis)

Psyche will carry four instruments with it to 16 Psyche, with the instruments weighing in at 30 kilograms total. The first instrument is a multispectral imager that will provide scientists with high-resolution imagery of 16 Psyche. The imager will use different filters to separate the metallic and silicate compounds on the asteroid’s surface.

Psyche will also carry a gamma-ray and neutron spectrometer. The instrument will map and analyze the entirety of 16 Psyche’s elemental composition. Alongside the gamma-ray and neutron spectrometer is Psyche’s magnetometer, which will measure, analyze, and map 16 Psyche’s magnetic field. If the asteroid was indeed once a planetary core, then it likely has a leftover magnetic field that can be measured and studied by the magnetometer.

The fourth and final instrument aboard the spacecraft is the X-band Gravity Science Investigation. Using the spacecraft’s X-band radio telecommunications system, the instrument will measure 16 Psyche’s gravitational field and investigate the interior structure of the asteroid.

The last major component of the Psyche spacecraft is the Deep Space Optical Communications (DSOC) laser communications experiment. During Psyche’s mission, teams will use laser communication to send commands to the spacecraft and relay data, increasing communications performance and efficiency by 10 to 100 times over normal communications systems. Psyche’s DSOC demonstration will be the first time NASA attempts to use laser communications to communicate with a spacecraft that is outside the Earth-Moon system.

The DSOC system consists of a flight laser transceiver, ground laser transmitter, and ground laser receiver. The flight laser transceiver is the part of the system that is mounted onto the Psyche spacecraft. Shortly after launch, communications with Psyche via the DSOC system will begin and are expected to last for one year after launch. Extended mission opportunities are available after the completion of the one-year-long primary mission.

The primary goal of the Psyche mission is to characterize the geology, shape, elemental composition, magnetic field, and mass distribution of 16 Psyche. As mentioned, 16 Psyche is thought to have once been a planetary core and could hold the answers to some of planetary science’s greatest mysteries surrounding planetary formation.

The specific scientific goals for the mission are to “understand a previously unexplored building block of planet formation: iron cores”; “look inside terrestrial planets, including Earth, by directly examining the interior of a differentiated body, which otherwise could not be seen”; and “explore a new type of world. For the first time, examine a world made not of rock and ice, but metal.”

What’s more, the mission’s science objectives are to “determine whether Psyche is a core, or if it is unmelted material”; “determine the relative ages of regions of Psyche’s surface”; “determine whether small metal bodies incorporate the same light elements as are expected in the Earth’s high-pressure core”; “determine whether Psyche was formed under conditions more oxidizing or more reducing than Earth’s core”; and “characterize Psyche’s morphology.”

Understanding the exact process behind planetary formation could allow scientists to better analyze and research the planets within our own solar system and exoplanets that are scattered throughout our universe. We will never be able to directly visit and study the cores of planets like Earth and Mars, but with 16 Psyche potentially being a metallic core just like Earth’s and Mars’, studying 16 Psyche will give scientists a window into the potential characteristics and past of Earth and Mars’ cores.

Graphic showing Psyche’s cruise trajectory to 16 Psyche. (Credit: NASA/JPL-Caltech)

Following its launch, Psyche will cruise through space for five years and 10 months, arriving at 16 Psyche in August 2029. During its cruise, Psyche will complete a gravity assist maneuver at Mars in 2026, which will increase the velocity of the spacecraft and put it on the proper trajectory to encounter 16 Psyche in 2029.

During this cruise phase, Psyche teams will be activating Psyche’s instruments and begin calibrating them for use at the asteroid. When Psyche performs its flyby of Mars, the various characteristics of Mars will be used to calibrate the instruments and ensure they’re in working order before the spacecraft’s arrival at 16 Psyche.

Once at 16 Psyche, the spacecraft will orbit the asteroid in four different orbits, which are named A-D, during its 21-month mission. The first orbit, Orbit A, will be 700 kilometers in altitude at a 90-degree inclination. Psyche will be in Orbit A for 56 days and will perform magnetic field characterization.

Psyche will then move to Orbit B1, which is 303 kilometers in altitude at a 90-degree inclination. The spacecraft will stay in Orbit B1 for 92 days for continued magnetic field and topography characterization.

Next, Psyche will lower to Orbit D, which is 75 kilometers in altitude at 160 degrees in inclination. Psyche will stay in Orbit D for 100 days and will investigate the chemical composition of the asteroid’s surface.

Graphic showing the different orbits Psyche will operate in while at 16 Psyche. (Credit: NASA/JPL-Caltech)

Psyche will then move up to Orbit C, a 190-kilometer high orbit at a 90-degree inclination. The spacecraft will be in Orbit C for another 100 days and will perform investigations into 16 Psyche’s gravitational and magnetic fields.

The final orbit Psyche will move to during its primary mission is Orbit B2, which is the same altitude and inclination as Orbit B1. However, this time, the spacecraft will stay in Orbit B2 for 100 days, performing more topography and magnetic field characterization.

Psyche’s launch

The launch of Psyche was the fourth flight of Falcon Heavy this year, and the rocket’s eighth mission of all time. Furthermore, Psyche’s launch marked SpaceX’s 73rd launch of 2023 and 277th mission overall.

Falcon Heavy debuted in 2018 and was the world’s most powerful operational rocket until the launch of NASA’s Space Launch System in 2022. The rocket stands 70 meters tall and masses 1.4 million kilograms at liftoff. The rocket is a tri-core design, with a central core and two side cores comprising the first stage of the rocket. At the bottom of each of the cores are nine Merlin 1D engines, which, together, produce approximately 22,000 kilonewtons of thrust. The upper stage of the rocket utilizes a single Merlin 1D Vacuum engine, which produces approximately 934 kilonewtons of thrust.

Given the reusable nature of Falcon 9, the three-core boosters on Falcon Heavy can also be recovered. The boosters supporting this mission were B1064-4, B1065-4, and B1079-1. B1064-4 and B1065-4 had both previously flown on Falcon Heavy missions as side boosters, supporting the USSF-44, USSF-67, and Echostar 24/Jupiter 3 missions. A launch on Oct. 13 would have the booster’s turnaround time be 76 days.

Following launch and their separation from the center core, the two side boosters turned around and landed back at Landing Zone 1 (LZ-1) and Landing Zone 2 (LZ-2) at the Cape Canaveral Space Force Station, which is just a few miles south of LC-39A, gaining the “-5” designation. After the launch of Psyche, these boosters will be turned around for the launch of the USSF-52 mission in late November.

The center core for this mission is B1079-1, which was expended into the Atlantic after its separation from the upper stage. Psyche’s total mass is 2,608 kilograms at launch, and, as such, SpaceX needed to expend the center core booster to ensure Falcon Heavy has enough capability to place Psyche on the correct launch trajectory.

Psyche’s Falcon Heavy first rolled out to LC-39A on Sept. 29 for its static fire. On Sept. 30, Falcon Heavy successfully completed its static fire, confirming that all 27 Merlin 1D engines were ready for flight. The rocket was then lowered and rolled back into the Horizontal Integration Facility at LC-39A for integration of Psyche, which is encapsulated in the payload fairing, to the top of the second stage.

Psyche encapsulated within its payload fairing. (Credit: NASA/Ben Smegelsky)

After the aforementioned launch delay from Oct. 5 to Oct. 12, Falcon Heavy rolled back out to LC-39A on Oct. 10 and was raised to the vertical position later that night.

On launch day, the countdown began with the powering-on of Falcon Heavy at T-10 hours. Teams then monitored the health of the rocket and the payload for the next nine hours and will continue to do so all the way up until liftoff.

At T-50 minutes, fuel load begins, and all three first stage boosters begin to be loaded with RP-1, a refined form of kerosene. Shortly afterward at T-45 minutes, liquid oxygen (LOX) will also begin to be loaded onto the first stage boosters.

As the first stage boosters are loaded with RP-1 and LOX, the second stage begins to be loaded with RP-1 at T-35 minutes. At T-18.5 minutes, second stage LOX load begins.

Propellant loading on both stages then continued until just a few minutes before liftoff. This is to ensure that the propellant in the boosters and second stag are as dense and chilled as possible. The colder and denser the propellant is, the better the rocket will perform during flight.

At T-7 minutes, first stage engine chill begins, which is when a small amount of LOX is trickled through the 27 Merlin 1D engines. This is done to avoid thermal shock when the engines ignite and LOX and RP-1 are flowing through the engines at full force.

After the completion of fuel loading, Falcon Heavy takes control of the countdown and enters startup at T-1 minute. The rocket’s fuel tanks are pressurized for flight shortly after, and the final go for launch given at T-45 seconds. At T-3 seconds, first stage engine ignition begins, with each booster igniting one after another in a staggered pattern to avoid inducing the rocket to extreme stress.

Finally, after confirming that all 27 engines are lit and working properly, Falcon Heavy and Psyche lifted off from LC-39A at T0.

Falcon Heavy and Psyche rolling out to LC-39A on Oct. 10. (Credit: NASA/Aubrey Gemignani)

Immediately following liftoff, Falcon Heavy rolled itself onto the proper launch alignment and will began throttling each of the three boosters. At T+1:09 minutes, the vehicle experienced maximum aerodynamic pressure, or max-Q, which is when aerodynamic and structural forces are at their greatest during ascent.

At approximately T+2:25 minutes after liftoff, the two side boosters shut down their engines in an event called booster engine cutoff (BECO). Three seconds after BECO, the two side boosters were jettisoned from the center core and began a synchronized flip. At the completion of the flip, the boosters ignited their engines and performed a boostback burn, which cancels all of their velocity to the east and places them on a trajectory to land back at LZ-1 and LZ-2.

The side boosters’ boostback burns completed at T+3:51 minutes, with main engine cut off (MECO) on the first stage occurring four seconds later. The first and second stages separated immediately following MECO, with the ignition of the second stage vacuum engine occurring at T+4:04 minutes.

The two fairing halves separated at T+4:24 minutes, exposing the Psyche spacecraft and its payloads to space for the first time. These fairings will be recovered by SpaceX’s recovery ship Bob

Falcon Heavy’s launch trajectory. (Credit: SpaceX)

As the second stage and Psyche continue to space, the side boosters’ landing operations began with the entry burns at T+6:47 minutes. The entry burns will complete at T+7:04 minutes, and the boosters took aim on LZ-1 and LZ-2. At T+8 minutes, the side boosters began the landing burn and will land on LZ-1 and LZ-2 just 17 seconds later.

The second stage Merlin Vacuum engine shut down at T+8:26 minutes, and coasted for approximately 46 minutes before igniting again at T+54 minutes. This second burn lasted around two minutes, with shutdown occurring at T+56:12 minutes. The second stage and Psyche coasted for a few more minutes before Psyche is deployed from the second stage at T+1:02:24 hours.

Psyche teams will immediately begin checking the health of the spacecraft and work to establish communications with the spacecraft. Furthermore, teams will deploy the solar panels and begin turning on instruments, such as the magnetometer.

16 Psyche

16 Psyche is a large, M-type asteroid located 2.92 astronomical units from the Sun within the asteroid belt. The asteroid was discovered on March 17, 1852, by Italian astronomer Annibale de Gasparis. M-type asteroids are a class of asteroids that contain higher concentrations of metallic elements and compounds than other classes of asteroids.

The “16” in the asteroid’s name signifies that the asteroid was the 16th minor planet to ever be discovered. The asteroid is named after the Greek goddess Psyche.

Artist’s depiction of 16 Psyche. (Credit: NASA/JPL-Caltech/ASU)

16 Psyche is the largest M-type asteroid to ever be discovered, and its large size is one of the main reasons why scientists selected the asteroid for the Psyche mission. Its mean diameter is around 220 kilometers, its volume is 5.75×10^6 cubic kilometers, and its mass is 2.29×10^19 kilograms. In fact, the asteroid is so large that it contains approximately one percent of the entire asteroid belt.

As mentioned, 16 Psyche is theorized to have once been a planetary core of a planetesimal, which is a forming planet. Scientists believe that the surface of the planetesimal was blown away by the near-constant collisions between it and other planetary materials that existed in the early solar system. Once the surface of the asteroid had been blown away, just the core of the asteroid was left, and this left-over core is thought to be what is presently known as 16 Psyche.

Scientists are still largely unsure of the shape of the asteroid, and won’t know what the exact shape of the asteroid will be until Psyche arrives at the asteroid in 2029. Based on observations from Earth-based telescopes, scientists believe the asteroid is a Jacobi ellipsoid with dimensions within a few kilometers of 278 kilometers by 238 kilometers by 171 kilometers. The asteroid is known to have several large craters and depressions on its surface.

Recent observations of the asteroid by NASA’s SOFIA and past studies have shown differences in surface brightness at various locations on 16 Psyche’s surface. These variations in surface brightness could hint at differences in the asteroid’s surface and internal composition.

Further observations of the asteroid have shown that Psyche’s surface is comprised of silicate materials. Observations taken in 2016 showed evidence of hydroxyl ions, which could hint at the presence of hydrated silicates on the surface of the asteroid.

Much is still not known about 16 Psyche, which makes the launch and arrival of Psyche at the asteroid even more exciting. M-type asteroids have never been extensively studied by a spacecraft, and Psyche’s mission, if successful could open the gate for more missions to M-type asteroids.

(Lead image: SpaceX’s Falcon Heavy rocket launches with Psyche from LC-39A. Credit: Sawyer Rosenstein for NSF)

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