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James Webb Space Telescope struck by micrometeoroid

NASA’s James Webb Space Telescope recently suffered a micrometeoroid strike to one of its 18 primary mirror segments, though engineers working on the mission insist the damage has been minimal.

The recently launched Webb telescope is the most powerful space observatory ever deployed and will soon start peering into deep space in a bid to learn more about the origins of the universe. The $10 billion multiyear mission is the result of a partnership between NASA, the European Space Agency, and the Canadian Space Agency, and has been decades in the making.

While it’s normal for spacecraft to experience micrometeoroid impacts, NASA noted that this particular speck of high-speed space dust, which hit the telescope between May 23 and May 25, was larger than any it had forecast when modeling such events prior to the mission’s launch in December 2021.

Analysis of the damage to the mirror segment is ongoing, but NASA said the early indications are that the telescope is continuing to perform “at a level that exceeds all mission requirements despite a marginally detectable effect in the data.”

Commenting on the strike, Paul Geithner, technical deputy project manager at NASA’s Goddard Space Flight Center, said: “We always knew that Webb would have to weather the space environment, which includes harsh ultraviolet light and charged particles from the sun, cosmic rays from exotic sources in the galaxy, and occasional strikes by micrometeoroids within our solar system. We designed and built Webb with performance margin — optical, thermal, electrical, mechanical — to ensure it can perform its ambitious science mission even after many years in space.”

The telescope, which is now in its observing spot about a million miles from Earth, has been able to adjust the affected segment in a way that cancels out a portion of the distortion caused by the micrometeoroid impact.

In a bid to avoid such strikes, NASA is able to instruct the spacecraft to perform protective maneuvers that move the telescope’s delicate optics away from known meteor showers heading its way.

However, the space agency notes that the recent hit was an “unavoidable chance event” that was not part of a meteor shower.

In response to the unexpected incident, NASA has formed a specialized team of engineers to examine if there are any ways it can help the spacecraft to reduce the effects of future micrometeoroid hits of this scale.

“With Webb’s mirrors exposed to space, we expected that occasional micrometeoroid impacts would gracefully degrade telescope performance over time,” said Lee Feinberg, Webb optical telescope element manager at NASA Goddard. “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.”

The size of the micrometeoroid was clearly something of a surprise for the Webb team, but the telescope’s careful design has ensured that it’s able to continue to function as expected.

The mission team is set to release the telescope’s first images in July as scientists seek to use the powerful observatory to unlock some of the secrets of the universe.

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