NASA Gives Up: Lucy Mission Suspending Further Solar Array Deployment Activities

NASA Lucy Mission Solar Array Anomaly

Shortly after Lucy launched, one of its solar arrays failed to fully deploy, putting the mission at risk.
NASA’s Lucy mission is heading to the Jupiter Trojans, two swarms of asteroids trapped in Jupiter’s orbit. Lucy made a picture-perfect launch in October 2021, but when the spacecraft began to unfurl its solar arrays, it encountered an anomaly. One of the arrays failed to fully deploy and latch shut, putting the mission at risk. For months, the flight operations team worked to address the issue – allowing Lucy to continue its journey to the Jupiter Trojans.
This artist’s concept animation depicts Lucy’s solar array anomaly.
Credit: NASA’s Goddard Space Flight Center Conceptual Image Lab

NASA’s Lucy mission team has decided to suspend further solar array deployment activities. The team determined that operating the mission with the solar array in the current unlatched state carries an acceptable level of risk and further deployment activities are unlikely to be beneficial at this time. The spacecraft continues to make progress along its planned trajectory.

Shortly after the spacecraft’s October 2021 launch, the mission team realized that one of Lucy’s two solar arrays had not properly unfurled and latched. A series of activities in 2022 succeeded in further deploying the array, placing it into a tensioned, but unlatched, state. Using engineering models calibrated by spacecraft data, the team estimates that the solar array is over 98% deployed, and it is strong enough to withstand the stresses of Lucy’s 12-year mission.

The team’s confidence in the stability of the solar array was affirmed by its behavior during the close flyby of the Earth on October 16, 2022, when the spacecraft flew within 243 miles (392 km) of the Earth, through the Earth’s upper atmosphere. The solar array is producing the expected level of power at the present solar range and is expected to have enough capability to perform the baseline mission with margin.

Lucy Trojan Asteroid Mission

Lucy will explore the Jupiter Trojan asteroids – thought to be “fossils of planet formation.” Credit: NASA’s Goddard Space Flight Center

The team elected to suspend deployment attempts after the attempt on December 13, 2022, produced only small movement in the solar array. Ground-based testing indicated that the deployment attempts were most productive while the spacecraft was warmer, closer to the Sun. As the spacecraft is currently 123 million miles (197 million km) from the Sun (1.3 times farther from the Sun than the Earth) and moving away at 20,000 mph (35,000 km/hr), the team does not expect further deployment attempts to be beneficial under present conditions.

Due to the energy boost that the spacecraft received during last October’s Earth gravity assist, the spacecraft is now on an orbit that will take it over 315 million miles (500 million km) from the Sun before returning to Earth for a second Earth gravity assist on December 12, 2024. Over the next year and a half, the team will continue to collect data on how the solar array behaves during flight. Most significantly, the team will observe how the array behaves during a maneuver in February 2024, when the spacecraft operates its main engine for the first time. As the spacecraft warms up during its approach to Earth in the fall of 2024, the team will re-evaluate if additional steps to reduce risk will be needed.

2 Comments on "NASA Gives Up: Lucy Mission Suspending Further Solar Array Deployment Activities"

  1. Wow! The perfection of science! Put these technicians on the Wuhan nih 91_divoc board!

    • What’s with the deplorable QAnoners commenting on this science site? It’s getting worse and worse with each month.

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