NASA’s James Webb Space Telescope sustained an impact to one of its primary mirror segments between May 23 and 25.
Our solar system is filled with small particles of rock or metal called micrometeoroids. These tiny meteoroids typically weigh less than a gram, yet they still pose a significant threat to spacecraft because their average speed relative to orbit is a staggering 22,500 mph (10 kilometers per second).
Micrometeoroid strikes are an unavoidable aspect of operating any spacecraft, which routinely sustain many impacts over the course of long and productive science missions in space. Between May 23 and 25, NASA’s James Webb Space Telescope sustained an impact to one of its primary mirror segments.
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. Thorough analysis and measurements are ongoing. Impacts will continue to occur throughout the entirety of Webb’s lifetime in space; such events were anticipated when building and testing the mirror on the ground. After a successful launch, deployment, and telescope alignment, Webb’s beginning-of-life performance is still well above expectations, and the observatory is fully capable of performing the science it was designed to achieve.
Webb’s mirror was engineered to withstand bombardment from the micrometeoroid environment at its orbit around Sun-Earth L2 of dust-sized particles flying at extreme velocities. While the telescope was being built, engineers used a mixture of simulations and actual test impacts on mirror samples to get a clearer idea of how to fortify the observatory for operation in orbit. This most recent impact was larger than was modeled, and beyond what the team could have tested on the ground.
“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,” said Paul Geithner, technical deputy project manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “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.”
For example, due to careful work by the launch site teams, Webb’s optics were kept cleaner than required while on the ground; their pristine cleanliness improves the overall reflectivity and throughput, thereby improving total sensitivity. This and other performance margins make Webb’s science capabilities robust to potential degradations over time.
Furthermore, Webb’s capability to sense and adjust mirror positions enables partial correction for the result of impacts. By adjusting the position of the affected segment, engineers can cancel out a portion of the distortion. This minimizes the effect of any impact, although not all of the degradation can be canceled out this way. 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. 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.
To protect Webb in orbit, flight teams can use protective maneuvers that intentionally turn the optics away from known meteor showers before they are set to occur. This most recent hit was not a result of a meteor shower and is currently considered an unavoidable chance event. As a result of this impact, a specialized team of engineers has been formed to look at ways to mitigate the effects of further micrometeoroid hits of this scale. Over time, the team will collect invaluable data and work with micrometeoroid prediction experts at NASA’s Marshall Space Flight Center to be able to better predict how performance may change, bearing in mind that the telescope’s initial performance is better than expected. Webb’s tremendous size and sensitivity make it a highly sensitive detector of micrometeorites; over time Webb will help improve knowledge of the solar system dust particle environment at L2, for this and future missions.
“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.”
This recent impact caused no change to Webb’s operations schedule, as the team continues to check out the science instruments’ observing modes and prepares for the release of Webb’s first images and the start of science operations.
How long does it take for an image from the observatory reaches the command Centre on earth? If this incident happened worst case on 23 May, it means it took about 16days for it to be registered here or at least for it to be reported in this article. Just curious
Taking into account the telescope is around 1.5 million km away and the speed of light is 300000 km/s, it will take only 5 seconds for the elecromagnetic signal caring the image to arrive to Earth.
Rethinking Telescope Mirrors material may be a option.can we use material on which micrometeoroid has no impact for future telescopes.
To the extent of micrometeoroid collision, and expected deterioration over time, can we use software to improve resolution and sharpen the image with contrast and brightness on the fly.
Can we figure out a way to repel the micrometeoroid dust particles using micro tractor beam technology to stop them from causing deterioration in the performance of the 10 billion dollar WEBB Space telescope? Remember reading about tractor technology becoming a reality in the lab.
Views expressed are personal and not binding on anyone.
kindly provide link for sharing on whakapp.
link for sharing via email is not working.
Took quite a while for the space telescope to intimate us of its injuries.
The materials that have the characteristics to withstand the force of hypervelocity projectile most likely do not have the properties to make an efficient mirror for a telescope. Additionally ballistics armor is heavy! Just ask the osteoarthritis in my spine and all my major joints how heavy ballistic Armor is LOL. I’m assuming that creating a shield out of ballistics material around the mirror would greatly reduce the ability of the telescope to capture imagery. Additionally if we had the ability to create a forcefield to repelled or stop hypervelocity projectiles The military would be utilizing that technology already, especially if it was light enough to launch into space. I think a better system would be an active defence rather than a passive defence system. A passive system has to constantly be on, which means constant power drawl. Electricity is a finite resource on a satellite. An active defence system would only use power when needed when it detects and defeats a specific threat. I think it would be more efficient to have a high powered laser designed to track and evaporate micrometeoroids. Rather than a constant blanket of a passive protection system an active system would only activate when a threat is present.