|Goals||NASA's Lucy mission will explore a record-breaking number of asteroids, flying by one asteroid in the solar system’s main asteroid belt, and by seven Trojan asteroids.|
|Launch Date||Oct. 16, 2021|
|Science Targets||Trojan Asteroids|
|Mission Website||NASA's Lucy Mission
Lucy is the first space mission launched to study the Trojan asteroids. Trojans are small bodies that are remnants of our early solar system. They orbit the Sun in two loose groups: one group leading ahead of Jupiter in its orbit, the other trailing behind.
During its 12-year primary mission, Lucy will explore a record-breaking number of asteroids, flying by one main belt asteroid, and seven Trojans.
No other space mission in history has been launched to as many different destinations in independent orbits around our Sun.
Lucy launched at 5:34 a.m. EDT on Oct. 16, 2021, on a United Launch Alliance Atlas V 401 rocket from Space Launch Complex-41 on Cape Canaveral Space Force Station in Florida. The spacecraft sent its first signal to Earth from its own antenna to NASA’s Deep Space Network at 6:40 a.m. EDT.
“Lucy embodies NASA’s enduring quest to push out into the cosmos for the sake of exploration and science, to better understand the universe and our place within it,” said NASA Administrator Bill Nelson. “I can’t wait to see what mysteries the mission uncovers!”
“We started working on the Lucy mission concept early in 2014, so this launch has been long in the making,” said Hal Levison, Lucy principal investigator, based out of the Boulder, Colorado, branch of Southwest Research Institute (SwRI), which is headquartered in San Antonio. “It will still be several years before we get to the first Trojan asteroid, but these objects are worth the wait and all the effort because of their immense scientific value. They are like diamonds in the sky.”
The spacecraft is traveling at roughly 67,000 mph (108,000 kph) on a trajectory that will orbit the Sun and bring it back toward Earth in October 2022 for the spacecraft’s first gravity assist. That maneuver will accelerate and direct Lucy’s trajectory beyond the orbit of Mars. The spacecraft will then swing back toward Earth for another gravity assist in 2024, which will propel Lucy toward the Donaldjohanson asteroid – located within the solar system’s main asteroid belt – in 2025.
Lucy will then journey toward its first Trojan asteroid encounter in the swarm ahead of Jupiter for a 2027 arrival. After completing its first four targeted flybys, the spacecraft will travel back to Earth for a third gravity boost in 2031, which will catapult it to the trailing swarm of Trojans for a 2033 encounter.
“Today we celebrate this incredible milestone and look forward to the new discoveries that Lucy will uncover,” Donya Douglas-Bradshaw, Lucy project manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said after the launch.
The Lucy mission is named after the fossilized skeleton of an early hominin (pre-human ancestor) discovered in Ethiopia in 1974 and named “Lucy” by the team of paleoanthropologists who discovered it.
Just as the Lucy fossil provided unique insights into humanity’s evolution, the Lucy mission promises to revolutionize our knowledge of planetary origins and the formation of the solar system, including Earth.
NASA's Goddard Space Flight Center provides overall mission management, systems engineering, plus 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.