cooccur with JWST ’s stunningfirst image , its operating team has publish a reputation on its commission . Most matter are going spectacularly well and repeatedly transcend prospect , as the figure ’s quality get clear – nevertheless , such near - perfection has a time limit . The reportnotes ; “ The mirror and sunshield are expect to slowly degrade from micrometeoroid impacts ; the detectors are carry to know cumulative slow terms from charged atom ; the sunshield and multilayer insulation will degrade from space weathering . ”
The report card also raise the hazard of more sudden failures , signal out that “ The science tool admit many move part at cryogenic temperatures . ”
These menace were all known long before launch and comprise into the expectation the scope would still be performing after five years of performance , probably well foresightful . So far , JWST is performing above requirements on all measure , and above prelaunch anticipation on most , raising hopes it should continue to operate even longer than planned . However , the one tent flap in the ointment can be see in the photograph below .
.png)
Wavefront sensing reveals noticeable damage to the C3 segment of the primary mirror (right), as compared to observations taken on Earth (left). Image Credit: NASA
The bright spotlight at the downhearted right present thepreviously reported“larger than anticipated ” micrometeoroid impingement in May .
Being reach by flying tinge of debris is an occupational hazard for any outer space cat’s-paw , and JWST ’s manipulator surely planned for such events . The theme acknowledges the impact that occurred between May 22 and 24 “ exceeded prelaunch expectations ” found on our knowledge of micrometeoroid populations .
Indeed , JWST ’s railroad engineer foresee each of the 18 mirror segment would suffer 16 nanometers of cumulative damage over a six - year operating flow . This work stoppage alone caused ten times that to the C3 segment – the account posit " The impact leaven the wavefront erroneous belief of section C3 from 56 to 280 nm rms . Mirror commanding to adapt section posture and curve reduced this error to 178 nm rms . "
.For some functions , this has made in effect no difference – but for others , it ’s make noticeable performance degradation .
Five other strike were detected at the meter the report was write last week , at a rate similar to arithmetic mean . Aside from the late May wallop , all were of anticipated sizing .
“ Some of the resulting wavefront degradation is correctable through regular wavefront control ; some of it incorporate high spatial frequency terms that can not be correct , ” the study notes . There have also been even smaller impacts , too small-scale to be notice using wavefront detection – but whose damage can build up with time .
Even the C3 encroachment did n’t forestall the stupefying quality of JWST ’s first images . The head remain whether it was simply risky luck that an unusually large shock fall out while the scope was still being commission , or if the relative frequency of impacts this large was underestimate . The scope ’s operators are enquire , although probably only meter will give a definitive solution . Meanwhile , the value of minimizing clock time spend take care in the direction of orbit , which is accompanied by more ( and more damaging ) micrometeoroid strikes , is being explored .
None of this should take away from the report ’s key end ; “ JWST is amply capable of achieving the discoveries for which it was built , " the report notes . " The telescope and instrument suite have demonstrated the sensitivity , stability , image character , and spiritual range that are necessary to transmute our sympathy of the cosmos through observations spanning from near - earth asteroid to the most remote galaxies . ”
