![]() The flight team can also perform protective maneuvers that intentionally turn the optics away from known meteor showers before they are set to occur. These steps will be repeated when needed in response to future events as part of the monitoring and maintenance of the telescope throughout the mission.” Engineers have already performed a first such adjustment for the recently affected segment C3, and additional planned mirror adjustments will continue to fine tune this correction. “This minimizes the effect of any impact, although not all of the degradation can be cancelled out this way. “By adjusting the position of the affected segment, engineers can cancel out a portion of the distortion,” wrote JWST media team member Thaddeus Cesari. The team said that with the capability to sense and adjust mirror positions enables partial correction for the result of impacts. NASA/Chris Gunn.Īnd JWST has one thing other space telescopes don’t have: the ability to adjust the mirror segments to within microns of precision. JWST’s mirror segments are prepped for testing at NASA’s Marshall Space Flight Center. During the telescope’s construction, engineers used a mixture of simulations and actual test impacts on mirror samples to get data on how to fortify the observatory for operation in space. The mirror segments were engineered to withstand bombardment from the known micrometeoroid environment (other spacecraft have been in orbit at the second Lagrange point L2), with dust particles flying at extreme velocities. Knowing this, we built Webb with large margins.” ![]() On Twitter, Feinberg said that with a 25 square meter primary mirror and large sun shield, “Webb will be hit by many of varying size. Meteoroid impacts are a known hazard of space flight and the telescope team has always known that impacts will occur throughout the entirety of JWST’s lifetime in space. ![]() But to be clear, we’re talking about small bits of dust at best, not rocks.” “I think: it’s hard to get a handle on the size without knowing the velocity. On Twitter, Mark McCaughrean, the European Space Agency’s Senior Advisor for Science & Exploration and part of JWST’s Science Working Group, said the exact size of the object is not known. The team said this most recent hit was not a result of a meteor shower and is currently considered an unavoidable chance event. The James Webb Space Telescope inside a cleanroom at NASA’s Johnson Space Center in Houston. 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.” “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. “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. However, after initial assessments, the team found the telescope is still performing at a level that exceeds all mission requirements despite a marginally detectable effect in the data. In a NASA blog post, JWST team members said that sometime between May 23 and May 25, one of the primary mirror segments sustained the larger impact, with a noticeable effect on the mirror segment’s performance. ![]() Scientists and engineers for the James Webb Space Telescope revealed that since its deployment in space, the telescope has been struck at least five times by micrometeroids, with one recent strike by an object that was larger than what pre-launch models suggested that the telescope would likely encounter.
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