Questions about the reliability of the transistors on the Europa Clipper spacecraft arose earlier this year after similar problems cropped up elsewhere. With the tight launch window looming, NASA rushed to conduct tests to verify that the electronic parts could survive the $5 billion mission to determine whether the suspected ocean beneath Europa’s icy crust might be suitable for life.

It will take six years for Europa Clipper to reach Jupiter, where it will orbit the gas giant every three weeks. Dozens of flybys are planned of Europa as close as 16 miles (25 kilometers), allowing cameras and other instruments — including ice-penetrating radar — to map virtually the entire moon.

Europa Clipper is the biggest spacecraft ever built by NASA to investigate another planet, spanning more than 100 feet (30 meters) with its solar panels unfurled.