On This Day: Webb telescope heads toward halo orbit - Dec. 25, 2021
(edited from Wikipedia)
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The James Webb Space Telescope (JWST) is a space telescope designed to conduct infrared astronomy. Its high-resolution and high-sensitivity instruments allow it to view objects too old, distant, or faint for the Hubble Space Telescope. This enables investigations across many fields of astronomy and cosmology, such as observation of the first stars and the formation of the first galaxies, and detailed atmospheric characterization of potentially habitable exoplanets.
The Webb was launched on 25 December 2021 on an Ariane 5 rocket from Kourou, French Guiana. In January 2022 it arrived at its destination, a solar orbit near the Sun–Earth L2 Lagrange point, about 1.5 million kilometers (930,000 mi) from Earth. The telescope's first image was released to the public on 11 July 2022.
Initial designs for the telescope, then named the Next Generation Space Telescope, began in 1996. Two concept studies were commissioned in 1999, for a potential launch in 2007 and a US$1 billion budget. The program was plagued with enormous cost overruns and delays. A major redesign was accomplished in 2005, with construction completed in 2016, followed by years of exhaustive testing, at a total cost of US$10 billion.
Bright early galaxies
Within two weeks of the first Webb images, several preprint papers described a wide range of high redshift and very luminous (presumably large) galaxies believed to date from 235 million years (z=16.7) to 280 million years after the Big Bang, far earlier than previously known.
On 17 August 2022, NASA released a large mosaic image of 690 individual frames taken by the Near Infrared Camera (NIRCam) on Webb of numerous very early galaxies.
Subsequent noteworthy observations and interpretations
In June 2023 detection of organic molecules 12 billion light-years away in a galaxy called SPT0418-47 using the Webb telescope was announced.
On 12 July 2023, NASA celebrated the first year of operations with the release of Webb’s image of a small star-forming region in the Rho Ophiuchi cloud complex, 390 light years away.
In September 2023, two astrophysicists questioned the accepted Standard Model of Cosmology, based on the latest James Webb Space Telescope studies.
In December 2023, NASA released Christmas holiday-related images by JWST, including the Christmas Tree Galaxy Cluster and others.
Ariane flight VA256
Ariane flight VA256 was an Ariane 5 rocket flight that launched the James Webb Space Telescope into space on 25 December 2021. It was 2021's final Ariane flight, its most valuable payload to date, and the 256th Ariane mission. The launch was described by NASA as "flawless" and "perfect".
Halo orbit
A halo orbit is a periodic, three-dimensional orbit near one of the L1, L2 or L3 Lagrange points in the three-body problem of orbital mechanics. Although a Lagrange point is just a point in empty space, its peculiar characteristic is that it can be orbited by a Lissajous orbit or by a halo orbit. These can be thought of as resulting from an interaction between the gravitational pull of the two planetary bodies and the Coriolis and centrifugal force on a spacecraft.
Halo orbits exist in any three-body system, e.g., a Sun–Earth–orbiting satellite system or an Earth–Moon–orbiting satellite system. Continuous "families" of both northern and southern halo orbits exist at each Lagrange point. Because halo orbits tend to be unstable, station-keeping using thrusters may be required to keep a satellite on the orbit.
Most satellites in halo orbit serve scientific purposes, for example space telescopes.
The James Webb Space Telescope entered a halo orbit around the Sun-Earth L2 point on 24 January 2022.
https://en.wikipedia.org/wiki/File:Lagrange_points2.svg
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https://en.wikipedia.org/wiki/James_Webb_Space_Telescope
https://en.wikipedia.org/wiki/Ariane_flight_VA256
https://en.wikipedia.org/wiki/Halo_orbit
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