It is a tiny rock. However, the damage it caused is enormous. And it caused it on a $10 billion telescope. The irreparable damage to the James Webb is a warning sign. How much is the telescope’s functions affected?
It was a micrometeoroid. It hit one of the telescope’s 18 hexagonal mirrors between May 22 and 24. Now an image showing the damage caused by the tiny rock has been revealed. It is substantial damage. But the effect on the overall performance of the James Webb appears to be minor.
Various impacts
The report highlights that the fuel reserve should last the telescope about 20 years. What is not clear is what impact the micrometeoroids will have in the future.
Impacts from these space bodies are not new. The International Space Station and the Hubble telescope also suffered them. But the James Webb is much farther away than they are. It is impossible to think of a repair.
That’s a total of six impacts. Some of these deformations can be corrected by aligning the mirrors. But one of them was stronger than the others. It is the one that caused the irreparable damage to the James Webb. One of the sections was too badly damaged to be fixed by simply aligning the mirrors.
Even so, only a small part of the total mirror area is affected. The other 17 mirror segments were not damaged. However, the question arises whether the mirror segments are as strong as calculated.
Dodging hits
Measures are currently being developed to avoid meteoroids. For example, restricting the direction in which the telescope is pointed. What does this involve? Minimizing the time during which the mirror is oriented in the direction of telescope motion. That is when the chance of hitting a micrometeoroid increases.
The development of these measurements is important. In 2023 and 2024 the James Webb is expected to pass through the particle clouds left in its wake by Halley’s comet.
