NASA’s Lucy launches on 12-year mission to Jupiter’s Trojan asteroids
By Joey Roulette
NASA embarked on a 12-year mission to study a group of asteroids Saturday with the launch of Lucy, a robotic explorer that will meander through the unexplored caverns of deep space to find new clues about the creation of our solar system.
The 5:34 a.m. Eastern time liftoff from Kennedy Space Center in Florida atop an Atlas 5 rocket from United Launch Alliance was the first step of Lucy’s 4-billion mile path into the orbital neighborhood of Jupiter. There, two swarms of asteroids known as the Trojans have hid for billions of years, leftover debris from the solar system’s early formation.
The spacecraft launched before dawn, setting off toward the orbit that will begin its elaborate trajectory. Lucy separated from the rocket’s second stage booster roughly 1 hour after liftoff and about a half-hour later unfurled two circular solar panels that will power the spacecraft throughout its journey.
Orbiting the sun on each side of Jupiter, the two clouds of dark asteroids have only been scrutinized by scientists from afar. Some 10,000 have been identified of the roughly 1 million that are estimated to exist. Lucy will be the first spacecraft to dive directly into the clusters to get close-up views of seven unique Trojan asteroids, plus one tiny asteroid in the solar system’s main asteroid belt.
“The last 24 hours has just been a roller coaster of excitement and buildup and everything was a success,” Hal Levison, Lucy’s principal investigator, said on a NASA livestream after launch. “We have one chance really to do this; the planets are literally aligning in order to make this trajectory happen.”
He and the mission’s other scientists hope that the sedan-size spacecraft will uncover pieces of evidence about the migration of planets to their current orbits.
What is Lucy?
The Lucy probe, named after the fossilized skeleton of an early hominid ancestor that transformed our understanding of human evolution, will use a suite of scientific instruments to analyze the Trojan asteroids — celestial fossils that the mission’s scientists hope will transform human knowledge about the formation of the solar system.
Managed by the Southwest Research Institute, with a spacecraft built for NASA by Lockheed Martin, the total cost of the mission is $981 million. The spacecraft is roughly the size of a small car and weighs about 3,300 pounds when filled with fuel.
Its scientific instruments include L’TES, or the Lucy Thermal Emission Spectrometer — a telescope designed to scan asteroid surfaces for infrared radiation and measure how quickly or slowly the space rocks’ surfaces heat up and cool down with exposure to the sun’s heat. Built by scientists at Arizona State University, the gadget is essentially an advanced thermometer. Analyzing how quickly the asteroids build up heat gives scientists an idea of how much dust and rocky material is scatted across their surfaces.
Another device is L’LORRI, or the Lucy Long Range Reconnaissance Imager, built by engineers and scientists at the Johns Hopkins Applied Physics Laboratory. This telescope will capture black-and-white images of the asteroids’ surfaces, revealing craters and ridges that have long been shrouded in darkness.
Lucy’s third tool, L’Ralph, has both a color camera and an infrared spectrometer. Each instrument is designed to detect bands of light emitted by ices and minerals scientists expect to be present on the asteroids’ surfaces.
How long is its mission?
The spacecraft will spend 12 years hunting down eight asteroids, embarking on an intricate path that uses Earth’s gravity three times to slingshot itself around the sun and through the two swarms of Trojans under Jupiter’s gravitational influence.
As it journeys from one side of Jupiter’s orbital path to the other, Lucy will travel roughly 4 billion miles during its primary mission.
What are the Trojan asteroids?
The Trojan asteroids are swarms of rocky material left over from the formation of our solar system 4.6 billion years ago. No spacecraft has ever visited the asteroids, which orbit the sun on each side of Jupiter and in the same orbital path, but at a great distance from the giant planet.
Before it gets to the Trojans, it will fly by an asteroid in the main belt between Mars and Jupiter that is named after Donald Johanson, the scientist who discovered the Lucy skeleton. The spacecraft will first visit 52246 Donaldjohanson in April 2025 and will then proceed to its primary destinations.
Lucy will make six flybys of the Trojan asteroids, one of which has a small moon, resulting in seven Trojans visited. The observations should give scientists a diverse set of asteroid material to analyze back on Earth.
What do scientists hope to learn from the Lucy mission?
The Trojan asteroids have been hidden in darkness and nearly impossible to analyze. Scientists expect them to be an unexplored fount of data to test theoretical models about the solar system’s formation and how the planets ended up in their current orbits around the sun.
What other deep-space missions does NASA have coming up soon?
Two more asteroid missions will eventually follow Lucy, along with:
— DART: Launching in November, NASA’s Double Asteroid Redirect Test (DART) mission involves crashing a spacecraft into an asteroid to nudge it off course. The mission tests out a method of planetary defense that could one day come in handy should an asteroid threaten Earth.
— James Webb Space Telescope: A roughly $10 billion follow-up to NASA’s well-known Hubble telescope, the Webb is scheduled to, at last, launch in December. It will study planets orbiting distant stars and search for light from the first galaxies that formed after the Big Bang.
— Artemis-1: NASA aims in the months ahead to launch an uncrewed Orion astronaut capsule atop its massive Space Launch System rocket around the moon and back. It’s the first mission under the agency’s Artemis program, which aims to one day send American astronauts back to the moon.
— Psyche: Next year, NASA is scheduled to send a probe to Psyche, a metallic asteroid in the belt between Mars and Jupiter made of nickel and iron that resembles the core of an early planetary body. Like the asteroids of Lucy’s mission, it could provide clues to the formation of our solar system.
— Europa Clipper: In 2024, NASA intends to send a spacecraft toward Jupiter to scan the icy moon Europa and determine whether its subsurface ocean could harbor life.