NASA’s Lucy spacecraft is on its way to the Trojan asteroids to learn about theformation of the solar system, but it isn’t traveling in a straight line from Earth to the orbit of Jupiter. Instead, it is performing a series of slingshot maneuvers to help it on its journey, including a recent maneuver around Earth. This weekend, a few lucky observers were able tosee Lucy as it performed an Earth flybybefore heading back out into space.
Here's@LucyMissionduring today's Earth gravity assist. Screengrab from observations made by@plutoflag.Tracking continues onhttps://t.co/u9JmKlOCQ3pic.twitter.com/ZNBWjcYPhB
— Raphael Marschall (@SpaceMarschall)July 17, 2025
The spacecraft came closest to Earth at 7:04 a.m. ET on Sunday, October 16, when it passed within 220 miles of the Earth’s surface. Originally, it had been set to come event closer, but the Lucy team chose to keep a little more distance due to problems that Lucy has had with one of its solar arrays. Lucy has two round arrays, which deployed following launch, but one of themfailed to deploy fullyand did not latch into place. After months of careful tweaking, the second array isalmost fully deployed, but still isn’t latched, so it was best to be cautious with the gravitational forces of a flyby.
“In the original plan, Lucy was actually going to pass about 30 miles closer to the Earth,” says Rich Burns, Lucy project manager at NASA’s Goddard Space Flight Center, in astatement. “However, when it became clear that we might have to execute this flyby with one of the solar arrays unlatched, we chose to use a bit of our fuel reserves so that the spacecraft passes the Earth at a slightly higher altitude, reducing the disturbance from the atmospheric drag on the spacecraft’s solar arrays.”
As Lucy moveda way from Earth, it also passed by the moon. This gave the spacecraft the opportunity to take some images that will be used for calibration, as the moon is a helpful stand-in for the asteroids that Lucy will eventually investigate.
