With the solar panels now operational, Lucy has some twinkling to do

Enlarge / A NASA rendering of the Lucy spacecraft before efforts were made to fully open one of its solar arrays in May and June.


NASA confirmed this week that its Lucy mission to explore a series of asteroids has a good health record heading into a key gravity-assist maneuver in October.

In a new update, the space agency said Lucy’s solar arrays are “stable enough” for the billion-dollar spacecraft to carry out science operations for the next few years as it visits a main-belt asteroid, 52246 Donaldjohanson, and then flies by eight Trojans. asteroids that share Jupiter’s orbit around the Sun.

The fate of the Lucy mission had been in question since the first hours after its launch on an Atlas V rocket last October, when one of its two large solar panels failed to fully open and lock into place. completely safe. Each of the paintings was intended to unfold like a fan.

Scientists and engineers from the space agency and its mission contractors, including spacecraft builder Lockheed Martin and solar panel designer Northrop Grumman, met hours after launch. In these early meetings, they had “intense” conversations about the fate of the mission. At the time, engineers weren’t sure why the solar panel hadn’t opened, as Lucy’s cameras couldn’t be aimed at the solar panels.

So in these early meetings, scientists and engineers debated whether the solar array problem could be solved and whether the mission could complete its ambitious science observations without two fully operational solar arrays. The partially closed grid was producing about 90% of its expected power.

Eventually, after months of analysis, testing and troubleshooting, the team realized that the cord designed to open the solar panel had become stuck. Lucy is equipped with both a main engine and a backup engine to deploy the solar panels, but they were not designed to be fired in tandem. This spring, engineers decided that the best course of action was to simultaneously fire up the main and backup deployment motors of the solar array in hopes that that extra force would unleash the lanyard.

So, from May 6 to June 16, on seven separate occasions, engineers commanded the deployment motors to power up, and those efforts helped. At 360 degrees, NASA says the solar panel is now open between 353 and 357 degrees. And while not fully locked down, it is now under sufficient voltage to function as needed during the mission.

With the solar array issue seemingly resolved, mission operators can focus on an October flyby of Earth when Lucy receives grav-assist, the first of three en route to the main asteroid belt. As part of this fuel-efficient trajectory, Lucy will fly past its first target in April 2025, the main-belt asteroid named after Donald Johanson, the American anthropologist who co-discovered the famous fossil “Lucy” in 1974. The fossil, of a species of female hominin that lived around 3.2 million years ago, supported the evolutionary idea that bipedalism preceded an increase in brain size.

The mission of the asteroid Lucy, in turn, takes its name from the famous fossil. By then visiting eight Trojan asteroids, scientists hope to glean information about the building blocks of the solar system and better understand the nature of its planets today.

No probes have passed by these small Trojan asteroids, which are clustered at stable Lagrange points lagging behind and ahead of Jupiter’s orbit 5.2 astronomical units from the Sun. Asteroids are mostly dark but can be coated in tholins, which are organic compounds that could provide raw materials for the basic chemicals of life.

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