Lucy asteroid probe forced to limp on without full solar array

Attempts to fix glitch ditched – but never give up, never surrender

NASA's Lucy spacecraft will have to soldier on to reach eight asteroids within Jupiter's orbit – a journey expected to last 12 years – with a glitch in one of its solar arrays for now.

Launched in October last year, the probe failed to fully latch one of its two solar arrays properly shortly after it left Earth. The panels, stretching seven meters across, are designed to fold out like a fan spread across 360 degrees. One solar array, however, hasn't quite opened all the way. 

Attempts to fix the issue have not been successful. Engineers are going to give up trying to solve the problem for the time being, and will continue to monitor Lucy as it flies towards Jupiter. "NASA's Lucy mission team has decided to suspend further solar array deployment activities," the space agency confirmed in a statement.

"The team determined that operating the mission with the solar array in the current unlatched state carries an acceptable level of risk and further deployment activities are unlikely to be beneficial at this time. The spacecraft continues to make progress along its planned trajectory."

The solar array is in a tensioned but unlatched state, meaning the panels have unfolded but haven't opened all the way. Models predict it is currently over 98 percent deployed, but will probably collect enough sunlight to power Lucy through the mission in the foreseeable future.

NASA admitted that the chances of reaching 100 percent deployment were minimal. It may take another stab at latching the solar array in late 2024 when the spacecraft flies closer to the Sun and gets warmer as it makes its way back toward Earth for a second gravity assist boost.

The maneuver will propel Lucy towards Jupiter, and allow it to fly by one main belt asteroid and seven Jupiter trojan asteroids described as the "fossils of planetary formation." The probe is aptly named after the series of bones from a female skeleton of an early hominid species, Australopithecus afarensis – a human ancestor estimated to have lived over three million years ago which was discovered in 1974. 

Asteroids are remnants from the formation of the solar system. The rocky chunks failed to coalesce into planets and provide scientists with clues about how they formed over 4.5 billion years ago. They all orbit the Sun and are categorized across different types and locations.

The main belt asteroids lie between Mars and Jupiter, while the trojan asteroids are split into two groups by the gravitational attraction of Jupiter and the Sun. Lucy will make two Earth flybys for gravity-assisted speed before reaching the trojans in 2033. ®