Skip to main content

Why the Psyche spacecraft’s futuristic electric thrusters glow blue

This artist’s concept depicts NASA’s Psyche spacecraft headed to the metal-rich asteroid Psyche in the main asteroid belt between Mars and Jupiter. The spacecraft launched in October 2023 and will arrive at its destination in 2029.
This artist’s concept depicts NASA’s Psyche spacecraft headed to the metal-rich asteroid Psyche in the main asteroid belt between Mars and Jupiter. The spacecraft launched in October 2023 and will arrive at its destination in 2029. NASA/JPL-Caltech/ASU

NASA’s Psyche mission is on its way to visit a strange metal asteroid located in the main asteroid belt between Mars and Jupiter, and it recently kicked on its blue-glowing electric thrusters to carry it on the next leg of its journey.

The electric thrusters are solar powered, and use ionized xenon for propulsion. These kind of thrusters aren’t powerful like the chemical propulsion systems used by rockets to escape Earth’s atmosphere, for example, but are instead extremely efficient. They produce only a very small amount of thrust, but in the vacuum of space there isn’t any drag to overcome so the spacecraft can continue gradually increasing in speed. For space travel beyond Earth’s orbit, the challenge is less about having powerful engines and more about conserving fuel.

This photo captures an operating electric thruster identical to those being used to propel NASA’s Psyche spacecraft. The blue glow comes from the charged atoms, or ions, of xenon.
This photo captures an operating electric thruster identical to those being used to propel NASA’s Psyche spacecraft. The blue glow comes from the charged atoms, or ions, of xenon. NASA/JPL-Caltech

The engines on Psyche, called Hall thrusters, could run continuously for years before using up all of the 2,030 pounds (922 kilograms) of xenon fuel the spacecraft carries. Regular chemical thrusters would use fuel at around 15 times that rate. The xenon fuel creates a blue glow from the thruster as the atoms become ionized by the thrusters’ electromagnetic fields, powered by the spacecraft’s solar panels.

This graphic depicts the path NASA’s Psyche spacecraft is following as it travels to the asteroid Psyche. The key milestones of the prime mission are labeled, including the Mars gravity assist in May 2026.
This graphic depicts the path NASA’s Psyche spacecraft is following as it travels to the asteroid Psyche. The key milestones of the prime mission are labeled, including the Mars gravity assist in May 2026. NASA/JPL-Caltech

Psyche is already located beyond the orbit of Mars, but it needs to travel back around to make a Mars gravity assist maneuver in 2026. That will help boost the spacecraft on its way to meet Psyche in 2029. Currently, the spacecraft is traveling at around 84,000 mph (135,000 kph), but with the help of its thrusters it will speed up to around 124,000 mph (200,000 kph).

Recommended Videos

With the spacecraft’s first 100 days in space complete, it will now be operating in full cruise mode on its way to its destination.

Please enable Javascript to view this content

“Until this point, we have been powering on and checking out the various pieces of equipment needed to complete the mission, and we can report they are working beautifully,” said Henry Stone, Psyche project manager at NASA’s Jet Propulsion Laboratory, in a statement. “Now we are on our way and looking forward to an upcoming close flyby of Mars.”

Georgina Torbet
Georgina has been the space writer at Digital Trends space writer for six years, covering human space exploration, planetary…
How to watch NASA’s Psyche mission launch to a metal asteroid this week
This artist's-concept illustration depicts the spacecraft of NASA's Psyche mission near the mission's target, the metal asteroid Psyche.

[UPDATE: NASA has called off Thursday's launch due to poor weather conditions and is now targeting Friday, October 13. Full details below]

NASA will launch its latest mission, Psyche, this week. The spacecraft will visit a strange asteroid that is thought to be made almost entirely of metal, studying it to understand more about the formation of planets in our solar system.

Read more
NASA’s Psyche mission goes ahead, but VERITAS mission is delayed
This illustration, updated as of March 2021, depicts NASA's Psyche spacecraft. Set to launch in August 2022, the Psyche mission will explore a metal-rich asteroid of the same name that lies in the main asteroid belt between Mars and Jupiter.

NASA recently announced that its mission to visit a metal asteroid, Psyche, has a new launch date of October 2023. The mission had originally been scheduled for August 2022 but missed its launch date due to not having enough time for testing all the equipment and software. To make sure the mission launches as planned this time, staff will be moved off the planned VERITAS mission to Venus, which will now be delayed by three years.

Following the Psyche spacecraft missing its launch date, NASA and its Jet Propulsion Laboratory commissioned an independent review into the issues which delayed the launch and has now announced how it will address the issues raised in the review report.

Read more
NASA’s Psyche mission to metal asteroid has a new launch date
This illustration, updated as of June 2020, depicts NASA’s Psyche spacecraft.

NASA's Psyche spacecraft, set to visit a mysterious metal asteroid, has been given a new launch date following a delay to its launch which was originally set for August 2022. The spacecraft missed its launch date due to technical problems with its software which were announced in June, but now it will launch in October 2023 instead.

By launching at this time, the spacecraft can follow a flight profile similar to the previously planned one. The spacecraft will perform a flyby of Mars for a gravity assist in 2026 and is scheduled to arrive at the asteroid Psyche in August 2029. The spacecraft will investigate the asteroid, also called Psyche, which is thought to be made almost entirely of metal. Studying the asteroid could help researchers learn about how planets formed, because the asteroid may have been in the early stages of becoming a planetary core.

Read more