This image of Enceladus was captured last week. Credit: NASA/JPL/SPACE SCIENCE INSTITUTE

NASA's Cassini spacecraft swooped past Enceladus, a tiny moon of Saturn, as planned on 12 March. But the dust analyser onboard failed just as the probe flew through the ice and gas plume that spews from the moon's south pole (see Nature 452, 139 ; 2008).

The glitch arose two hours before the flyby, when the team responsible for the instrument tried to upload a software patch to speed up its counting rate to as high as 100 particles per second.

Uploading the patch took only a few microseconds, but unfortunately coincided with a higher-priority command from the main spacecraft. The patch fizzled. “It's really frustrating,” says Sascha Kempf, deputy principal investigator for the instrument at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany. Kempf says the team can update the software in time for the next flyby in August.

The 11 other data recorders on the spacecraft worked fine. “We're disappointed in the one instrument,” says Dennis Matson, project scientist for the mission at the Jet Propulsion Laboratory in Pasadena, California. “But it's more than outweighed by all the great stuff we did get.”