If all goes well, and it is by no means assured, in a week, James Webb’s $ 10 billion …
If all goes well, and by no means assured, in a week’s time the $ 10 billion James Webb Space Telescope (JWST) is expected to finally launch more than 30 years after its conception.
The efforts of thousands of scientists, engineers and managers from NASA, the European Space Agency (ESA), the Canadian Space Agency (CSA) and JWST prime contractor Northrop Grumman have made it possible to bring JWST to its launch pad in Kourou, French Guiana.
NASA today announced that the launch of JWST is now scheduled for December 24, 2021 at 7:20 a.m. EST. JWST is currently on top of an ESA Ariane 5 rocket, a very reliable work tool for transporting heavy loads. All verifications have been completed and JWST is ready to launch… the countdown is on. It is no exaggeration to say that everyone involved in building JWST, and the worldwide astronomical community that is so eager to use JWST, is likely feeling a mixture of tension, anxiety and euphoria as the time to take off is approaching.
At the time of JWST’s design in the early 1990s, Ariane 5 was the only rocket capable of launching the largest space telescope ever built. JWST is so large that it had to be designed so that it could be folded to fit inside the Ariane 5’s payload fairing and then unfolded to its maximum size once in space. .
This, as you will see, is no easy task. In contrast, the Hubble Space Telescope (HST), deployed on April 24, 1990 from the Space Shuttle, has a more conventional telescope design with a single 2.5 meter (100 inch) main mirror essentially enclosed in a spacecraft at telescope tube that orbits the Earth at an altitude of several hundred kilometers.
JWST, on the other hand, is a very large telescope or more specifically an Optical Telescope Element (OTE) that mounts above a fully capable spacecraft bus consisting of the power supply subsystem, sub- attitude control system, communication subsystem, command and data. Material handling subsystem, propulsion subsystem and thermal control subsystem.
JWST has 18 gold coated hexagonal shaped beryllium mirror segments that give the telescope an opening of 6.5 meters (256 inches). A single mirror of this size is far too large to fit in the Ariane 5’s payload fairing, so the design of the telescope had to incorporate two folding brackets each containing three mirror segments that will unfold and lock into place. side of the other twelve mirror segments which are stationary. The secondary mirror that will send the light collected from the 18 mirror segments to the four instruments mounted on the back of the telescope must also be bent to fit.
Oh, and because JWST is designed to collect light that includes the infrared portion of the spectrum, it needs to be cooled to around -380 degrees Fahrenheit so that there is no heat from the telescope to overwhelm the dim light from all of them. first stars and galaxies, hopefully. form in our Universe. You reach this seemingly impossible temperature by using a tennis court-sized five-layer deployable sunshade and park your spacecraft-telescope 1,000,000 miles from Earth at a point called L2. For an expected lifespan of five to hopefully ten years and maybe even longer, JWST will never be exposed to light (heat) from the Sun, Earth and Moon because of the sunshade. and the L2 orbit.
Due to its folded design, JWST must run very precisely and include 344 separate actions that must be completed successfully on time and in the correct order. It will take 30 days to get to L2 and a planned six-month check that will prepare the super-chilled telescope-spacecraft for the start of scientific observations. Summer 2022 is on schedule for when JWST will reach ‘first light’, that magical milestone in the existence of every telescope, when it is first exposed to the light of the Universe and an image. obtained.
First Light for HST was a disaster as it was determined that the blurry images meant the telescope’s mirror was poorly represented and could not focus on a sharp image. NASA took great care to avoid a similar event by testing JWST’s optics in several ways to ensure accurate optical performance. Additionally, unlike HST’s single primary mirror, JWST’s 18 mirror segments can be individually “dimmed” (moved) for optimum performance.
To present the developing story of JWST to our OMCP audience, I applied and was among those selected by NASA to attend a two-day JWST launch media access event. at the Space Telescope Science Institute (STScI) and at the JWST Mission Operations Center (MOC). I will conduct interviews, attend briefings, visit MOC and attend the launch of JWST.
To provide you with the very latest information on JWST developments, WTOP will have a live blog that I will post to for you to follow from December 22-24. Our blog can also be supplemented with live reporting. Photos, videos and commentary from the house of JWST operations will be special to share with our WTOP audience.
In over 30 years that I’ve been following this story, never, in my wildest dreams, have I thought, “Spending Christmas Eve with JWST is for me. “
Join me as I witness a whole new era of much anticipated astronomical discoveries made possible by the James Webb Space Telescope. The things we will see and discover are expected to revolutionize our understanding of the Universe, just as the HST and all of the other major new telescopes have done over the centuries, starting with Galileo.
Stay tuned because it all starts when that countdown hits “0” and ESA lights that Ariane 5 candle.
See Greg’s previous stories on JWST:
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