NASA Webb in full focus, ready for instrument operation
The alignment of NASA’s James Webb Space Telescope is now complete. After a thorough review, the observatory has been confirmed to be capable of capturing sharp, well-focused images with each of its four powerful scientific instruments. After completing the seventh and final phase of the telescope alignment, the team held a series of key decision meetings and unanimously agreed that Webb was ready to proceed with the next and final set of preparations, known as the commissioning of scientific instruments. This process will take about two months before the scientific work begins in the summer. Webb Space Telescope image sharpness test. Credit: NASA / STScI The telescope alignment across all Webb instruments can be seen in a series of images that capture the full field of view of the observatory. “These remarkable test images from a successfully aligned telescope show what people in countries and continents can achieve when there is a bold scientific vision for exploring the universe,” said Lee Feinberg, Webb’s telescope’s director at Goddard Space Flight. NASA. The Webb telescope completes the alignment phase. Credit: NASA Goddard Space Flight Center The telescope’s optical performance continues to be better than the engineers’ most optimistic predictions. Webb mirrors now direct fully focused light that is collected from space down into each instrument, and each instrument successfully captures images with the light provided to them. The image quality provided on all instruments is “diffraction limited”, which means that the detail that can be seen is as good as possible of course, given the size of the telescope. From this point on, the only changes to the mirrors will be very small, periodic adjustments to the main mirror sections. “With the telescope alignment complete and half the effort it owed my life, my role in the James Webb Space Telescope mission is coming to an end,” said Scott Acton, Webb’s detection and control scientist at Ball Aerospace. “These images have profoundly changed the way I look at the universe. We are surrounded by a creation agreement. there are galaxies everywhere! I hope everyone in the world sees them. “ Mechanical images of stars with a clear focus on the field of view of each instrument show that the telescope is fully aligned and focused. For this test, Webb showed part of the Large Magellanic Cloud, a small galaxy satellite of the Galaxy, providing a dense field of hundreds of thousands of stars to all of the observatory’s sensors. The sizes and positions of the images shown here illustrate the relative arrangement of each of Webb’s instruments in the telescope’s focal plane, each pointing slightly at one of the skies relative to each other. Webb’s three imaging instruments are the NIRCam (images shown here at 2 microns), the NIRISS (image shown here at 1.5 microns) and the MIRI (displayed at 7.7 microns, a longer wavelength that reveals emission from interstellar clouds as well as starlight). NIRSpec is a spectrograph and not an imaging device, but it can capture images, such as the 1.1 micron image shown here, for calibration and target shooting. The dark areas visible in parts of the NIRSpec data are due to the structures of the micro-diaphragm device, which has several hundred thousand controlled shutters that can be opened or closed to select which light will be sent to the spectrograph. Finally, Webb’s Fine Guidance Sensor monitors guiding stars to show the observatory accurately and precisely. Its two sensors are not generally used for scientific imaging, but they can capture calibration images such as those shown here. This image data is used not only to evaluate image sharpness, but also to accurately measure and calibrate subtle image distortions and alignments between sensors as part of the overall Webb instrument calibration process. Credit: NASA / STScI The Webb team will now focus on outsourcing. Each instrument is a highly sophisticated set of detectors equipped with unique lenses, masks, filters and personalized equipment that helps it perform the science designed to succeed. The specialized features of these instruments will be configured and operated in various combinations during the commissioning phase of the instrument to fully confirm their readiness for science. With the official completion of the telescope alignment, key personnel involved in the commissioning of each instrument have arrived at the Mission Operations Center at the Baltimore Space Telescope Science Institute, and some telescope alignment staff have completed their duties. Although the telescope alignment is complete, some telescope calibration activities remain: As part of the operation of a scientific instrument, the telescope will be commanded to show different areas in the sky where the total amount of sunlight hitting the observatory will vary to vary. the thermal stability when changing targets. In addition, continuous maintenance observations every two days will monitor the alignment of the mirrors and, where necessary, apply corrections to keep the mirrors in their aligned positions.
