The Lucy Mission: Piecing Together the History of the Solar System

A 12-year mission to study the Asteroids surrounding Jupiter could reveal archaeological insights about the outer planets.

The Lucy spacecraft passing one of the Trojan Asteroids near Jupiter. Artist illustration courtesy Southwest Research Institute / NASA.

On Saturday, a ULA Atlas V rocket will launch from Cape Canaveral, Florida carrying NASA’s Lucy spacecraft, a mission with the potential to transform our current knowledge of the solar system and planetary origins.

During its 12-year journey, Lucy will gather valuable insights by studying seven Trojans and one main belt asteroid surrounding Jupiter. Lucy, named for the 3.2 million-year-old fossilized human ancestor discovered in 1974, will be the first mission to study the Trojans — two groups of asteroids sharing Jupiter’s orbit thought to be remnants of the same material that formed the outer planets.

The endeavor features several unique characteristics: a long mission lifecycle, a complex path to navigate, and multiple targets in independent orbits around the Sun.

A Long Mission Lifespan

During its prime mission, Lucy will venture nearly 4 billion miles. The elaborate voyage will entail traveling more than three loops around the Sun using special circular solar arrays to generate the appropriate amount of power to complete its long journey. In another first, Lucy will travel out to Jupiter and return to Earth’s proximity — a maneuver necessary to initiate a gravity assist to send the space probe back to Jupiter’s orbit to conduct the final Trojan flybys.

During its prime mission, Lucy will venture nearly 4 billion miles. Artist illustration courtesy: Southwest Research Institute/NASA

“Lucy is an unusually long mission and has a particularly complicated path through the solar system because of the multiple targets it will study,” said Allison Moeller, Senior Engineer Specialist in the Integrated Cost & Schedule Analysis Department at Aerospace. “Spacecraft go out and study things, but the different encounters provide a new level of complexity.”

The longevity and numerous intended targets of study are distinctive qualities that presented challenges in understanding the mission’s essential needs. Relying on the heritage of NASA’s New Horizons and OSIRIS-REx — prior missions which carried similar instruments to those onboard Lucy — allowed for better assessment and identification of potential risks.

A Window of Opportunity

Because of the orbital mechanics and intricate interplanetary course the spacecraft must navigate, the window for launch is fixed at about three weeks, starting October 16, if Lucy is to reach all of its planned targets. This small launch window still allows no room for error; the carefully calculated mission course means Lucy can observe each subject only once before proceeding to its next point of interest.

The United Launch Alliance (ULA) payload fairing secured around NASA’s Lucy spacecraft on Sept. 30, 2021. Photo courtesy NASA

“Throughout different points in the development stage, we assembled teams of experts to review prior work and identify possible risks that may not be fully realized,” said Nishant Prasadh, of the Aerospace Vehicle Design and Innovation Department. These evaluations throughout the project development helped to identify potential gaps, estimate their impact on the mission, and work with NASA to mitigate hazards.

On launch day, a team will monitor the countdown and lift off from the Spacelift Telemetry Acquisition and Reporting System (STARS) Mission Operations Center at Aerospace. In STARS, the launch vehicle telemetry and related findings will be processed and displayed, and the information archived as sample data. To confirm the nominal performance of the launch vehicle, Aerospace will conduct fleet surveillance operations with a comprehensive system-level view of the rocket’s functions.

Uncovering the Unknown

With the instruments onboard, Lucy will gain an in-depth view of its targets, ranging from the Asteroids’ material composition to surface temperature. The data gathered could help unlock a bigger picture of our Solar System.

Once in space, patience will be required while the spacecraft conducts multiple flybys on its complex route. In the end, the mission staff anticipates the information gathered by Lucy will have an enormous impact.

“The fossil Lucy was considered a missing link, and that’s the motivation for naming this mission Lucy,” Moeller said. “We’re hoping to find our own missing link: the history of giant planet formation. NASA’s Lucy is meant to go out, study asteroids, learn more about them, and hopefully provide more insight on how those planets were formed.”