When NASA sent the James Webb Space Telescope (JWST) 1.5 million kilometers away last Christmas, there was great concern. Meteor dust.
A tiny speck of space dust hit the 18 beryllium segments of a $10 billion space telescope not once, but 14 times, causing irreparable damage.blogclarified in
“As expected, there have been 14 measurable meteor dust impacts on the primary mirror so far, averaging one or two per month,” says NASA’s Goddard Space in Greenbelt, Maryland, said Mike Menzel, lead mission systems engineer. by Webb at the Flight Center. “All but one of the resulting optical defects was within budget expectations when the telescope was built.”
That exception occurred in May, when meteoric dust struck the beryllium segment that makes up the JWST’s 6.5-metre primary mirror. Classified as an “unavoidable accidental event”, the telescope has been slightly misaligned since the accident. Engineers adjusted 18 mirrors to accommodate the damaged segments.
Space is a dangerous place to work, with threats such as cosmic rays from across the universe, the sun’s strong ultraviolet rays, and charged particles and meteoric dust flying at terrifying speeds.
But JWST engineers are already adopting workarounds to reduce the risk of further damage to the precious space telescope.NASA working groupconcluded that the May 2022 collision was a statistically rare event, but the giant space telescope has since moved away from what it calls a “meteor dust avoidance zone.” Statistically, more meteor dust travels at higher speeds from the opposite direction of the telescope’s orbit, meaning it minimizes the time spent looking in that direction.
The riskiest times are meteor showers, caused by particles left behind in the inner solar system. This is a potential short-term scenario, and one that is of particular concern in May 2023 and May 2024, when Webb navigates the Halley dust stream.
“A meteoric dust hitting a telescope mirror head-on (moving in the opposite direction to the direction of motion of the telescope) has twice the normal relative velocity and four times the kinetic energy, so it avoids this direction whenever possible. Avoidance has The effect of extending the excellent optical performance of JWST for decades,” said Lee Feinberg, Webb Optical Telescope Element Manager at NASA Goddard.
As a result, the JWST program was revised, prioritizing safe-time target sightings over scientific urgency. The exception is solar system lenses, which are much more time sensitive.
The $10 billion Webb Space Telescope, which observes the infrared portion of the spectrum, was launched on Christmas 2021 and has been orbiting Lagrange Point 2 (L2), about 1.6 million kilometers from Earth, since February 2022.
Wishing for clear skies and big eyes.
