Lucy Enters Cruise Mode, but Solar Array Issue Persists

NASA is continuing to investigate what is wrong with the solar array of Lucy, its spacecraft launched last week to visit the Trojan asteroids but says that the spacecraft is healthy and is traveling along the correct trajectory.

Lucy was launched last Saturday, October 16, and the launch went off successfully without any issues. However, hours after liftoff, there was a problem when the spacecraft went to deploy its 24-feet-wide solar arrays. One array deployed as planned, but the other array failed to lock into place.

Since then, technicians have been working to figure out what the exact problem is. The solar arrays are so large that they have to be folded up for launch to fit into the rocket, then they are designed to unfurl once the craft is in space. However, for reasons which remain unclear, one of the arrays only partially unfurled.

The good news is that even not fully unfurled, the array can still collect solar power. NASA says the array is “generating nearly the expected power” and that the combined power of this and the other fully deployed array “is enough to keep the spacecraft healthy and functioning.”

The craft had been in safe mode (a minimal, basic version of its operations) while the issue was investigated, but on Wednesday, October 20, the craft transitioned into cruise mode successfully. That means that the craft will be making more autonomous adjustments as it travels, and it is operating as expected so far.

“The spacecraft remains stable, power positive, with all other subsystems working, with the exception of one solar array,” NASA wrote in an update.

The update went on to say that the team will continue testing to find out what went wrong with the solar array deployment before they attempt to complete the deployment process: “NASA is reviewing spacecraft data, including using techniques to measure how much electric current is produced by the array during various spacecraft positions and attitudes. This will allow the team to understand how close the array is to the latched position. These techniques are well within the capabilities of the system and pose no risk. Any plans for re-deployment will be considered after completing this latest assessment.”

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