The telescope’s space pocket is not an absolute void – and now the inevitable has happened, with a tiny piece of rock, a micrometeorite, colliding with one of Webb’s mirror sections. But there is no need to panic. The engineers who built the telescope are extremely aware of the rigidity of space, and Webb has been carefully designed to withstand them. “We always knew that Webb would have to overcome the space environment, which includes hard ultraviolet light and charged particles from the Sun, cosmic rays from exotic sources in the galaxy and occasional micrometeorite impacts into our solar system,” says the engineer and technical. NASA Goddard Space Flight Center Deputy Project Director Paul Geithner “We designed and built the Webb with a margin of performance – optical, thermal, electrical, mechanical – to ensure that it can accomplish its ambitious scientific mission even after many years in space.” Webb’s position in L2. (NASA) Webb covers an area of 1.5 million kilometers (just under 1 million miles) from Earth called L2. This is what is known as the Lagrange or Lagrange point, where the gravitational interaction between two bodies in orbit (in this case, the Earth and the Sun) balances with the centripetal force of the orbit to create a stable pocket where low objects can be found. mass. parked ”to reduce fuel consumption. This is very useful for science, but these sites can collect other things as well. Jupiter, for example, has clusters of asteroids that share its orbit at two of the Lagrange points it shares with the Sun. Other planets also have asteroids at their Lagrange points, though probably fewer than Jupiter. It is not clear exactly how much dust L2 has picked up, but it would be foolish to expect that the area had not picked up at all. Thus, Webb was specifically designed to withstand the bombardment of dust particles traveling at extremely high speeds. Not only did Webb’s design include simulations, engineers performed test strikes on mirror specimens to understand what the effects of the space environment might be and to try to mitigate them. Impacts can move parts of a mirror, but the telescope has sensors to measure the positions of its mirrors and their ability to adjust them to help correct any distortions that may occur. Mission Control here on Earth can also send customizations to the Webb to place mirrors where they should be. Its view can even be distracted by known meteor showers in advance. And Webb was built with huge error margins, so that the physical degradation expected over time does not bring the mission to an early end. Damage from orbital impact on Hubble panels returned to Earth after a service mission. (NASA) It is probably in a better position than Hubble, which, in low orbit around the Earth, has been hit not only by micrometeorite impacts but also by constant space bombardment. Unlike Hubble, however, the distance from the Webb means that technicians will not be able to visit and make repairs. (Not that Hubble was recently served; the last such mission was in 2009 and it will not receive any more.) The micrometeorology that struck the telescope – sometime between May 23 and 25 – was a coincidence. The impact, however, was greater than expected, which means it represents an opportunity to better understand the L2 environment and try to find strategies to protect the telescope in the future. “With Webb mirrors exposed to space, we expected that occasional micrometeorological impacts would gracefully degrade the telescope’s performance over time,” said Lee Feinberg, director of Webb optical telescope data at NASA Goddard. “Since the launch, we have had four smaller measurable micrometeorological impacts that were in line with expectations and the most recent one, which is higher than our forecast for the downgrade. “We will use this flight data to update our performance analysis over time and also develop business approaches to ensure that we maximize Webb visualization performance to the best of our ability for many years to come.” The first color and spectroscopic images from the Webb are yet to arrive on schedule, on July 12, 2022. We look forward to it.
