James Webb Space Telescope inline

James Webb Space Telescope in full focus after completing alignment

Image credit: Nasa

Nasa has announced that its James Webb Space Telescope (JWST) is now fully aligned, allowing it to image distant stars and galaxies in unprecedented detail.

Initial tests of the Telescope’s instruments showed it is capable of capturing crisp, well-focused images with each of its four onboard science instruments.

It is now ready to move forward into its next and final series of preparations, known as science instrument commissioning. This process will take about two months and will allow scientific operations to begin.

“These remarkable test images from a successfully aligned telescope demonstrate what people across countries and continents can achieve when there is a bold scientific vision to explore the universe,” said Lee Feinberg, Webb optical telescope element manager at Nasa’s Goddard Space Flight Center.

The engineering team said the optical performance of the telescope is superior to its most optimistic predictions.

The image quality delivered to all instruments is “diffraction-limited,” meaning that the fineness of detail that can be seen is as good as physically possible given the size of the telescope. From this point forward the only changes to the mirrors will be very small, periodic adjustments to the primary mirror segments.

“With the completion of telescope alignment and half a lifetime’s worth of effort, my role on the James Webb Space Telescope mission has come to an end,” said Scott Acton, Webb wavefront sensing and controls scientist, Ball Aerospace.

“These images have profoundly changed the way I see the universe. We are surrounded by a symphony of creation; there are galaxies everywhere! It is my hope that everyone in the world can see them.”

The team now needs to commission the telescope’s science instruments – each one features a highly sophisticated set of detectors equipped with unique lenses, masks, filters, and customised equipment.

Though telescope alignment is complete, some telescope calibration activities remain. As part of the scientific instrument commissioning, the telescope will be commanded to point to different areas in the sky where the total amount of solar radiation hitting the observatory will vary to confirm thermal stability when changing targets.

Furthermore, ongoing maintenance observations every two days will monitor the mirror alignment and, when needed, apply corrections to keep the mirrors in their aligned locations.

JWST was launched on Christmas Day 2021, after which it underwent an agonising months-long process of slowly unfurling its sunshield as Nasa engineers anxiously watched on to see whether it had been damaged during the launch process.

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