From May 6 to June 16, NASA’s Lucy mission team carried out a multi-stage effort intended to further deploy the spacecraft’s unlatched solar array. The team commanded the spacecraft to operate the array’s deployment motor for limited periods of time, allowing them to closely monitor the response of the spacecraft. As a result of this effort, the mission succeeded in further deploying the array and now estimates that the solar array is between 353 degrees and 357 degrees open (out of 360 total degrees for a fully deployed array). Additionally, the array is under substantially more tension, giving it significantly more stabilization. The mission team is increasingly confident the solar array will successfully meet the mission’s needs in its current tensioned and stabilized state.
Further deployment attempts will be paused as the Lucy spacecraft enters a planned period of limited communications. Due to thermal constraints caused by the relative positions of the Earth, spacecraft, and Sun, the spacecraft will be unable to communicate with the Earth via its high-gain antenna for several months. Throughout this period, the spacecraft will remain in contact with Lucy’s ground team via its low-gain antenna. The spacecraft will emerge from this partial communications blackout after its Earth gravity assist maneuver on Oct 16. At that time, the mission team will have more opportunities to attempt further deployment efforts if deemed necessary.
On June 21, the spacecraft successfully carried out a trajectory correction maneuver, which is the second in a series of maneuvers to prepare the spacecraft for its Earth flyby.
UPDATE AS OF JUNE 20, 2022: The Lucy team executed another deployment attempt on June 16. Although there was still no latch, the attempt reeled in additional lanyard and further stabilized the array. Future opportunities still exist to repeat the deployment commands if necessary.
UPDATE AS OF JUNE 14, 2022: The Lucy team executed another deployment attempt on June 9 with no latch. The attempt continued to further stabilize the array, and there are future opportunities to repeat the deployment commands if necessary.
NASA’s Lucy mission team is in the midst of a multi-stage effort to further deploy the spacecraft’s unlatched solar array. On May 9, the team commanded the spacecraft to operate the array’s deployment motor using both the primary and back-up motor windings simultaneously to generate more torque, i.e. a harder pull. The motor operated as expected, further reeling in the lanyard that pulls the solar array open. After running the motor for a series of short intervals to avoid overheating, the team paused to analyze the results. Data from the spacecraft showed that the deployment was proceeding similarly to engineering ground tests, allowing the team to move forward with the second stage of the attempt. Analysis of the data also suggested that there was still additional lanyard to be retracted. The team sent the same commands again on May 12. Although this series of commands did not latch the solar array fully open, it did advance the deployment enough to increase the tension that stabilizes the arrays as was hoped.
On May 26, the spacecraft was again commanded to deploy the solar array. As in the first two attempts, both motor windings were operated simultaneously for short periods of time to avoid overheating. Afterwards the team again analyzed the data from the event, which again showed that the array was continuing to open. The team repeated the deployment command sequence a fourth time on June 2. While the array still did not latch, the data indicates that it continued to further deploy and stiffen throughout the attempt.
The team has several more opportunities to repeat these deployment commands. While there is no guarantee that additional attempts will latch the array, there is strong evidence that the process is putting the array under more tension, further stabilizing it. Even if the array does not ultimately latch, the additional stiffening may be enough to fly the mission as planned.
The spacecraft completed a trajectory correction maneuver on June 7. This was the first in a series of maneuvers the spacecraft will take in preparation for the mission’s first Earth gravity assist scheduled for October 16, 2022.