With the solar arrays now on, Lucy has some flashing to do

NASA confirmed this week that its Lucy mission to explore a series of asteroids has a clean bill of health as it approaches its main gravity assist maneuver in October.

In a new updateThe space agency said the Lucy Solar Arrays are “stable enough” for the $1 billion spacecraft to carry out its science operations over the coming years as it visits the main belt asteroid, 52246 DonaldJohansson, and then flies by eight Trojan asteroids that share Jupiter. revolve around the sun.

The fate of the Lucy mission has been in question since the early hours after its launch on an Atlas V rocket last October when one of its massive solar arrays failed to fully open and latch securely. Each of the arrays was intended to open up like a hand fan.

Scientists and engineers from the space agency and its mission contractors, including spacecraft builder Lockheed Martin and solar array designer Northrop Grumman, gathered within hours of launch. In those initial meetings, they had “intense” talks about the mission’s fate. At the time, engineers were not sure why the opening of the solar array failed because Lucy’s cameras could not be pointed toward the solar arrays.

So during those early meetings, scientists and engineers debated whether the solar array problem could be fixed and whether the mission could complete its ambitious science observations without two fully functional solar arrays. The partially closed group was generating about 90 percent of its expected power.

Eventually, after months of analysis, testing, and troubleshooting, the team realized that the cord designed to open the solar array had malfunctioned. The Lucy was equipped with a base engine and a backup engine for solar array deployment, but they were not designed to be launched in tandem. This spring, engineers decided that the best course of action was to fire both the solar array’s primary and backup deployment drives simultaneously in the hope that this extra power would separate the cord.

Therefore, from May 6 to June 16, on seven different occasions, engineers ordered the deployment of engines to start, and these efforts helped. Out of the full 360 degrees, NASA says the solar array is now open between 353 and 357 degrees. And while it’s not completely shut down, it’s now under enough pressure to operate as needed during the mission.

With the solar array problem apparently resolved, mission operators can shift their focus to a near-Earth flyby in October when Lucy will pick up gravitational assistance — the first of three on its way to the main asteroid belt. As part of this fuel-efficient trajectory, Lucy will fly by its first target in April 2025, a major belt asteroid named after Donald Johansson, the American anthropologist who co-discovered the famous “Lucy” fossil in 1974. Living about 3.2 million years ago, it supported the evolutionary idea that walking on two legs preceded an increase in brain size.

Asteroid mission Lucy, in turn, takes its name from the famous fossil. By visiting eight Trojan asteroids later, scientists expect to gather information about the building blocks of the solar system and better understand the nature of its planets today.

No probe has flown by these tiny Trojan asteroids, which cluster at stable Lagrangian points far behind and before Jupiter’s orbit 5.2 astronomical units from the Sun. Asteroids are mostly dark but may be covered with tholins, which are organic compounds that can provide the raw materials for chemicals essential to life.