Skip to main content

How NASA is dealing with micrometeoroids threatening James Webb

In June this year, NASA revealed that the James Webb Space Telescope had suffered from a micrometeoroid impact, in which a small space rock had caused some damage to one of the telescope’s 18 primary mirror segments. Although the damage was not serious enough to interfere with science operations, it did raise concerns about how much damage the telescope could suffer from similar impacts in the future. Now, NASA has shared its plan to deal with the issue of such impacts as Webb ages.

The Webb team knew that some impacts from micrometeoroids would be inevitable, as there are many such small particles in the area where Webb orbits around the sun. The telescope was designed to withstand small impacts, but a NASA working group concluded it was just bad luck that it was hit by a larger impact so soon after its launch in December 2021. An impact of that size was a “rare statistical event,” NASA said, both in that it was larger than most such impacts and that it happened to hit a particularly sensitive part of the telescope.

​​“We have experienced 14 measurable micrometeoroid hits on our primary mirror, and are averaging one to two per month, as anticipated. The resulting optical errors from all but one of these were well within what we had budgeted and expected when building the observatory,” said Mike Menzel, Webb lead mission systems engineer, in a statement. “One of these was higher than our expectations and prelaunch models; however, even after this event our current optical performance is still twice as good as our requirements.”

To protect Webb from such impacts in the future, the telescope will be used in such a way that it avoids facing the “micrometeoroid avoidance zone.” This helps avoid micrometeoroids striking the telescope’s primary mirror head-on, as these strikes are generally faster and are particularly damaging. The telescope will still be able to image all regions of the sky, but it will point at different regions at different times of the year to minimize the risk of impacts. This will begin with the second year of Webb science observations, called Cycle 2, which will start in July 2023.

Editors' Recommendations

Georgina Torbet
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
Webb telescope captures Ring Nebula in gorgeous detail
The Ring Nebula captured by Webb’s IRCam (Near-Infrared Camera).

The James Webb Space Telescope has just served up a couple more sublime images, this time showing the Ring Nebula in astonishing detail.

First spotted in the 18th Century and located around 2,500 light-years from Earth, the Ring Nebula’s colorful main ring is made up of gas thrown off by a dying star at the center of the nebula.

Read more
How to watch NASA and SpaceX launch Crew-7 to the space station
SpaceX's Crew-7 astronauts.

NASA Live: Official Stream of NASA TV

NASA and SpaceX are making final preparations for the Crew-7 flight to the International Space Station (ISS).

Read more
James Webb captures image of the most distant star ever discovered
A massive galaxy cluster called WHL0137-08 contains the most strongly magnified galaxy known in the universe’s first billion years: the Sunrise Arc, and within that galaxy, the most distant star ever detected, nicknamed Earendel.

The James Webb Space Telescope has captured a stunning image of the most distant star ever discovered. Discovered by Hubble in 2020, the star named Earendel is located an astonishing 28 billion light-years away. While in the previous Hubble image, the star was only visible as a small blob, these new observations from Webb are detailed enough to reveal information about the star like its type and information about the galaxy in which it resides.

The Webb image shows a galaxy cluster called WHL0137-08, which is so massive that it bends spacetime and acts like a magnifying glass for the more distant galaxies behind it. Some of these distant galaxies being magnified include one called the Sunrise Arc, which hosts Earendel. The Sunrise Arc is located near the end of one of the spikes from the bright central star, at around the five o'clock position. A zoomed-in version of the image shows the Arc and Earendel within t.

Read more