Over at L2, things got a little interesting for our still-dead-to-me telescope, JWST. It seems that sometime between May 23 and 25, the mirror segment labeled C3 sustained an impact from a micrometeorite. However, before anyone either panics or cackles with glee, initial assessments have shown that the telescope is still exceeding mission requirements.

Also, don’t cackle with glee. Scientists are depending on this telescope for data.

Micrometeorites are an expected and natural hazard of hanging about in space, and JWST’s mirror was engineered to withstand these impacts. Not only was extensive engineering and testing performed before launch, but the mirror segments can be adjusted to make corrections in the event of these impacts.

Now, not all of the damage can be negated, which is why there are also mitigation procedures in place to minimize these strikes. For example, the flight team will maneuver the optics away from known meteor showers before passing through the dust field. But the operations team expects some telescope degradation over time. Optical telescope element manager Lee Feinberg notes: Since launch, we have had four smaller measurable micrometeoroid strikes that were consistent with expectations and this one more recently that is larger than our degradation predictions assumed. We will use this flight data to update our analysis of performance over time and also develop operational approaches to assure we maximize the imaging performance of Webb to the best extent possible for many years to come.

This largest impact will have no effect on the operations schedule or the upcoming release of JWST’s first science images on July 12.

More Information

Webb: Engineered to Endure Micrometeoroid Impacts (NASA)

How Hardy Is Webb? A Q&A About the Toughness of NASA’s Webb Telescope (NASA)