Webb telescope still performing well after micrometeoroid impact on mirror segment, NASA says

A high-speed dust-size micrometeoroid slammed into one of the James Webb Space Telescope's 18 primary mirror segments last month, causing a slight but noticeable effect on the segment's performance, NASA said Wednesday. It was the fifth such impact detected since Webb's Christmas Day launch.

Given the $10 billion telescope's open design, with its mirrors exposed to space, engineers expected random hits by bits of space dust over the life of the observatory, but an impact between May 23 and 25 was larger than pre-flight models predicted.

After analyzing the C3 mirror segment's post-impact performance, engineers sent commands to actuators on the back of the mirror to ever-so-slightly reposition it, counteracting most, but not all, of the impact's observed results. Even with the hit, NASA said the telescope is still operating better than pre-flight requirements.