NASA’s Lucy spacecraft has been traveling through space on its way to visit the Trojan asteroids since its launch last October, but the team faced an unexpected problem with its deployment.
The problem is in one of Lucy’s two solar panels. These had to be folded for launch so the spacecraft could fit inside the launch vehicle, then deployed once Lucy reached space. The arrays deploy by fan-unfolding into two distinctive circular shapes that should then have been locked in place.
Artistic illustration of the Lucy mission. Southwest Research Institute
But one solar panel failed to lock properly after deployment on October 17, 2021. The array was nearly fully deployed and was still able to supply solar power to the spacecraft, but it was not locked in place as it should have been. to be. The mission team chose to continue with the craft in cruise mode as planned because the combined two arrays generated enough power to continue the mission.
Now, though, NASA wants to try to lock the array back in place. Engineers on the ground conducted tests and looked at data from the spacecraft and concluded that the array in question is open to 345 out of 360 degrees and still producing enough power. But there are concerns that if and when the spacecraft fires its main engine, the unlocked solar panel could be damaged.
In a recent update, NASA announced that on Monday, April 18, the team decided to continue trying to fix the array in its proper place. To do that, they work with the engine that drives the array implementation. “After launch, the arrays were opened by a small motor that coils into a cord attached to both ends of the folded solar panel,” NASA writes. “The team estimates that 20 to 40 inches of this cord (out of approximately 290 inches in total) has yet to be retracted to lock the open array.”
The array has both a primary and backup motor for this implementation, so engineers will try to use both motors together to pull the string through and lock the array in place. Tests show that the extra torque from using either motor can be enough to pull the cord out of its problem.
Implementing this plan requires two steps. The first step, scheduled to begin the week of May 9, is to pull the cord tight, which will allow the team to verify that the spacecraft is in the same condition as the tests on the ground and will also help keep the array safe. strengthen . The second step, scheduled for a month after step one if all goes well, is to use the two motors to try and pull the array into place.