Jump to content

NASA’s Lucy Spacecraft Prepares Second Asteroid Encounter


Recommended Posts

  • Publishers
Posted

NASA’s Lucy spacecraft is 6 days and less than 50 million miles (80 million km) away from its second close encounter with an asteroid; this time, the small main belt asteroid Donaldjohanson.

Download high-resolution video and images from NASA’s Scientific Visualization Studio.
NASA/Dan Gallagher

This upcoming event represents a comprehensive “dress rehearsal” for Lucy’s main mission over the next decade: the exploration of multiple Trojan asteroids that share Jupiter’s orbit around the Sun. Lucy’s first asteroid encounter – a flyby of the tiny main belt asteroid Dinkinesh and its satellite, Selam, on Nov. 1, 2023 – provided the team with an opportunity for a systems test that they will be building on during the upcoming flyby.

Lucy’s closest approach to Donaldjohanson will occur at 1:51pm EDT on April 20, at a distance of 596 miles (960 km). About 30 minutes before closest approach, Lucy will orient itself to track the asteroid, during which its high-gain antenna will turn away from Earth, suspending communication. Guided by its terminal tracking system, Lucy will autonomously rotate to keep Donaldjohanson in view. As it does this, Lucy will carry out a more complicated observing sequence than was used at Dinkinesh. All three science instruments – the high-resolution greyscale imager called L’LORRI, the color imager and infrared spectrometer called L’Ralph, and the far infrared spectrometer called L’TES – will carry out observation sequences very similar to the ones that will occur at the Trojan asteroids.

However, unlike with Dinkinesh, Lucy will stop tracking Donaldjohanson 40 seconds before the closest approach to protect its sensitive instruments from intense sunlight.

“If you were sitting on the asteroid watching the Lucy spacecraft approaching, you would have to shield your eyes staring at the Sun while waiting for Lucy to emerge from the glare. After Lucy passes the asteroid, the positions will be reversed, so we have to shield the instruments in the same way,” said encounter phase lead Michael Vincent of Southwest Research Institute (SwRI) in Boulder, Colorado. “These instruments are designed to photograph objects illuminated by sunlight 25 times dimmer than at Earth, so looking toward the Sun could damage our cameras.” 

Fortunately, this is the only one of Lucy’s seven asteroid encounters with this challenging geometry. During the Trojan encounters, as with Dinkinesh, the spacecraft will be able to collect data throughout the entire encounter.

After closest approach, the spacecraft will “pitch back,” reorienting its solar arrays back toward the Sun. Approximately an hour later, the spacecraft will re-establish communication with Earth.

“One of the weird things to wrap your brain around with these deep space missions is how slow the speed of light is,” continued Vincent. “Lucy is 12.5 light minutes away from Earth, meaning it takes that long for any signal we send to reach the spacecraft. Then it takes another 12.5 minutes before we get Lucy’s response telling us we were heard. So, when we command the data playback after closest approach, it takes 25 minutes from when we ask to see the pictures before we get any of them to the ground.”

Once the spacecraft’s health is confirmed, engineers will command Lucy to transmit the science data from the encounter back to Earth, which is a process that will take several days.

Donaldjohanson is a fragment from a collision 150 million years ago, making it one of the youngest main belt asteroids ever visited by a spacecraft. 

“Every asteroid has a different story to tell, and these stories weave together to paint the history of our solar system,” said Tom Statler, Lucy mission program scientist at NASA Headquarters in Washington. “The fact that each new asteroid we visit knocks our socks off means we’re only beginning to understand the depth and richness of that history. Telescopic observations are hinting that Donaldjohanson is going to have an interesting story, and I’m fully expecting to be surprised – again.”

NASA’s Goddard Space Flight Center in Greenbelt, Maryland, designed and built the L’Ralph instrument and provides overall mission management, systems engineering and safety and mission assurance for Lucy. Hal Levison of SwRI’s office in Boulder, Colorado, is the principal investigator. SwRI, headquartered in San Antonio, also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Littleton, Colorado, built the spacecraft, designed the original orbital trajectory and provides flight operations. Goddard and KinetX Aerospace are responsible for navigating the Lucy spacecraft. The Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, designed and built the L’LORRI (Lucy Long Range Reconnaissance Imager) instrument. Arizona State University in Tempe, Arizona, designed and build the L’TES (Lucy Thermal Emission Spectrometer) instrument. Lucy is the thirteenth mission in NASA’s Discovery Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama.

By Katherine Kretke, Southwest Research Institute

Media Contact:
Karen Fox / Molly Wasser
Headquarters, Washington
202-358-1600
karen.c.fox@nasa.gov / molly.l.wasser@nasa.gov

Nancy N. Jones
NASA’s Goddard Space Flight Center, Greenbelt, Md.

Share

Details

Last Updated
Apr 14, 2025
Editor
Madison Olson
Contact
Location
Goddard Space Flight Center

View the full article

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Similar Topics

    • By European Space Agency
      Video: 00:02:14 On 12 March 2025, ESA’s Hera spacecraft soared just 5000 km above Mars and passed within 300 km of its distant moon, Deimos. Captured by Hera’s 1020x1020 pixel Asteroid Framing Camera, this video sequence offers a rare view of the red planet and its enigmatic moon. The original greyscale images have been colour-enhanced based on known surface features.
      View the full article
    • By European Space Agency
      Image: This image shows Webb’s recent observation of the asteroid 2024 YR4 using both its Near-Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI). Data from NIRCam shows reflected light, while the MIRI observations show thermal light.
      On 8 March 2025, the NASA/ESA/CSA James Webb Space Telescope turned its watchful eye toward asteroid 2024 YR4, which we now know poses no significant threat to Earth in 2032 and beyond.
      This is the smallest object targeted by Webb to date, and one of the smallest objects to have its size directly measured.
      Observations were taken to study the thermal properties of 2024 YR4, including how quickly it heats up and cools down and how hot it is at its current distance from the Sun. These measurements indicate that this asteroid does not share properties observed in larger asteroids. This is likely a combination of its fast spin and lack of fine-grained sand on its surface. Further research is needed, however this is considered consistent with a surface dominated by rocks that are roughly fist-sized or larger.
      Asteroid 2024 YR4 was recently under close watch by the team at ESA's Near Earth Objects Coordination Centre, located in Italy. Planetary defence experts from the Agency's Space Safety programme worked with NASA and the international asteroid community to closely watch this object and refine its orbit, which was eventually determined to not pose a risk of Earth impact. Read details on this unusual campaign via ESA's Rocket Science blog and in news articles here and here.
      Webb’s observations indicate that the asteroid measures roughly 60 meters (comparable to the height of a 15-story building).
      The new observations from Webb not only provide unique information about 2024 YR4’s size, but can also complement ground-based observations of the object's position to help improve our understanding of the object’s orbit and future trajectory.
      Note: This post highlights data from Webb science in progress, which has not yet been through the peer-review process.
      [Image description: A collage of three images showing the black expanse of space. Two-thirds of the collage is taken up by the black background sprinkled with small, blurry galaxies in orange, blue, and white. There are two images in a column at the right side of the collage. On the right side of the main image, not far from the top, a very faint dot is outlined with a white square. At the right, there are two zoomed in views of this area. The top box is labeled NIRCam and shows a fuzzy dot at the center of the inset. The bottom box is labeled MIRI and shows a fuzzy pinkish dot.]
      View the full article
    • By European Space Agency
      The European Space Agency (ESA) has powered down its Gaia spacecraft after more than a decade spent gathering data that are now being used to unravel the secrets of our home galaxy.
      On 27 March 2025, Gaia’s control team at ESA’s European Space Operations Centre carefully switched off the spacecraft’s subsystems and sent it into a ‘retirement orbit’ around the Sun.
      Though the spacecraft’s operations are now over, the scientific exploitation of Gaia’s data has just begun.
      View the full article
    • By European Space Agency
      As ESA’s Hera planetary defence mission flew past planet Mars it autonomously locked onto dozens of impact craters and other prominent surface features to track them over time, in a full-scale test of the self-driving technology that the spacecraft will employ to navigate around its target asteroids.
      View the full article
    • By NASA
      Although NASA’s Lucy spacecraft’s upcoming encounter with the asteroid Donaldjohanson is primarily a mission rehearsal for later asteroid encounters, a new paper suggests that this small, main belt asteroid may have some surprises of its own. New modeling indicates that Donaldjohanson may have been formed about 150 million years ago when a larger parent asteroid broke apart; its orbit and spin properties have undergone significant evolution since.
      This artist’s concept compares the approximate size of Lucy’s next asteroid target, Donaldjohanson, to the smallest main belt asteroids previously visited by spacecraft — Dinkinesh, visited by Lucy in November 2023, and Steins — as well as two recently explored near-Earth asteroids, Bennu and Ryugu. Credits: SwRI/ESA/OSIRIS/NASA/Goddard/Johns Hopkins APL/NOIRLab/University of Arizona/JAXA/University of Tokyo & Collaborators When the Lucy spacecraft flies by this approximately three-mile-wide space rock on April 20, 2025, the data collected could provide independent insights on such processes based on its shape, surface geology and cratering history.
      “Based on ground-based observations, Donaldjohanson appears to be a peculiar object,” said Simone Marchi, deputy principal investigator for Lucy of Southwest Research Institute in Boulder, Colorado and lead author of the research published in The Planetary Science Journal. “Understanding the formation of Donaldjohanson could help explain its peculiarities.”
      “Data indicates that it could be quite elongated and a slow rotator, possibly due to thermal torques that have slowed its spin over time,” added David Vokrouhlický, a professor at the Charles University, Prague, and co-author of the research.
      Lucy’s target is a common type of asteroid, composed of silicate rocks and perhaps containing clays and organic matter. The new paper indicates that Donaldjohanson is a likely member of the Erigone collisional asteroid family, a group of asteroids on similar orbits that was created when a larger parent asteroid broke apart. The family originated in the inner main belt not very far from the source regions of the near-Earth asteroids Bennu and Ryugu, recently visited respectively by NASA’s OSIRIS-REx and JAXA’s (Japan Aerospace Exploration Agency’s) Hayabusa2 missions.
      “We can hardly wait for the flyby because, as of now, Donaldjohanson’s characteristics appear very distinct from Bennu and Ryugu. Yet, we may uncover unexpected connections,” added Marchi.
      “It’s exciting to put together what we’ve been able to glean about this asteroid,” said Keith Noll, Lucy project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “But Earth-based observing and theoretical models can only take us so far – to validate these models and get to the next level of detail we need close-up data. Lucy’s upcoming flyby will give us that.”
      Donaldjohanson is named for the paleontologist who discovered Lucy, the fossilized skeleton of an early hominin found in Ethiopia in 1974, which is how the Lucy mission got its name. Just as the Lucy fossil provided unique insights into the origin of humanity, the Lucy mission promises to revolutionize our knowledge of the origin of humanity’s home world. Donaldjohanson is the only named asteroid so far to be visited while its namesake is still living.
      “Lucy is an ambitious NASA mission, with plans to visit 11 asteroids in its 12-year mission to tour the Trojan asteroids that are located in two swarms leading and trailing Jupiter,” said SwRI’s Dr. Hal Levison, mission principal investigator at the Boulder, Colorado branch of Southwest Research Institute in San Antonio, Texas. “Encounters with main belt asteroids not only provide a close-up view of those bodies but also allow us to perform engineering tests of the spacecraft’s innovative navigation system before the main event to study the Trojans. These relics are effectively fossils of the planet formation process, holding vital clues to deciphering the history of our solar system.”
      Lucy’s principal investigator is based out of the Boulder, Colorado, branch of Southwest Research Institute, headquartered in San Antonio. NASA’s Goddard Space Flight Center in Greenbelt, Maryland, provides overall mission management, systems engineering, and safety and mission assurance. Lockheed Martin Space in Littleton, Colorado, built the spacecraft. Lucy is the 13th mission in NASA’s Discovery Program. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Discovery Program for the agency’s Science Mission Directorate in Washington.
      By Deb Schmid and Katherine Kretke, Southwest Research Institute
      Media Contact:
      Karen Fox / Molly Wasser
      Headquarters, Washington
      202-358-1600
      karen.c.fox@nasa.gov / molly.l.wasser@nasa.gov

      Nancy N. Jones
      NASA’s Goddard Space Flight Center, Greenbelt, Md.
      Share
      Details
      Last Updated Mar 17, 2025 EditorMadison OlsonContactNancy N. Jonesnancy.n.jones@nasa.govLocationGoddard Space Flight Center Related Terms
      Goddard Space Flight Center Lucy Missions Planetary Science Planetary Science Division Explore More
      3 min read NASA’s Lucy Spacecraft Takes Its 1st Images of Asteroid Donaldjohanson
      Article 3 weeks ago 3 min read NASA’s Lucy Asteroid Target Gets a Name
      Article 2 years ago 4 min read NASA Lucy Images Reveal Asteroid Dinkinesh to be Surprisingly Complex
      Article 10 months ago View the full article
  • Check out these Videos

×
×
  • Create New...