THE JAMES WEBB SPACE TELESCOPE IS LAUNCHED IN 2021

Today, The Grandma has received the wonderful visit of one of her closest friends, Joseph de Ca'th Lon. 

Joseph loves Science and Astronomy, and they have been talking about the James Webb Space Telescope, that was launched on a day like today in 2021.

The James Webb Space Telescope (JWST) is a space telescope which conducts infrared astronomy. As the largest optical telescope in space, its high resolution and sensitivity allow it to view objects too old, distant, or faint for the Hubble Space Telescope.

This will enable investigations across many fields of astronomy and cosmology, such as observation of the first stars, the formation of the first galaxies, and detailed atmospheric characterization of potentially habitable exoplanets.

The U.S. National Aeronautics and Space Administration (NASA) led JWST's design and development and partnered with two main agencies: the European Space Agency (ESA) and the Canadian Space Agency (CSA).

The NASA Goddard Space Flight Center (GSFC) in Maryland managed telescope development, the Space Telescope Science Institute in Baltimore on the Homewood Campus of Johns Hopkins University operates JWST, and the prime contractor was Northrop Grumman.

The telescope is named after James E. Webb, who was the administrator of NASA from 1961 to 1968 during the Mercury, Gemini, and Apollo programs.

The James Webb Space Telescope was launched on 25 December 2021 on an Ariane 5 rocket from Kourou, French Guiana, and arrived at the Sun–Earth L2 Lagrange point in January 2022. The first JWST image was released to the public via a press conference on 11 July 2022.

More information: James Webb Space Telescope

JWST's primary mirror consists of 18 hexagonal mirror segments made of gold-plated beryllium, which combined create a 6.5-meter-diameter mirror, compared with Hubble's 2.4 m. This gives JWST a light-collecting area of about 25 square meters, about six times that of Hubble. Unlike Hubble, which observes in the near ultraviolet and visible (0.1 to 0.8 μm), and near infrared (0.8–2.5 μm) spectra, JWST observes in a lower frequency range, from long-wavelength visible light (red) through mid-infrared (0.6–28.3 μm).

The telescope must be kept extremely cold, below 50 K (−223 °C; −370 °F), such that the infrared light emitted by the telescope itself does not interfere with the collected light. It is deployed in a solar orbit near the Sun-Earth L2 Lagrange point, about 1.5 million kilometers from Earth, where its five-layer sunshield protects it from warming by the Sun, Earth, and Moon.

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 in 2005 led to the current approach, with construction completed in 2016 at a total cost of US$10 billion. The high-stakes nature of the launch and the telescope's complexity were remarked upon by the media, scientists, and engineers.

The James Webb Space Telescope has a mass that is about half of Hubble Space Telescope's mass. The JWST has a 6.5-meter-diameter gold-coated beryllium primary mirror made up of 18 separate hexagonal mirrors.

The mirror has a polished area of 26.3 m2, of which 0.9 m2 is obscured by the secondary support struts, giving a total collecting area of 25.4 m2. This is over six times larger than the collecting area of Hubble's 2.4-meter diameter mirror, which has a collecting area of 4.0 m2. The mirror has a gold coating to provide infrared reflectivity and this is covered by a thin layer of glass for durability.

JWST is designed primarily for near-infrared astronomy, but can also see orange and red visible light, as well as the mid-infrared region, depending on the instrument.

More information: Webb Telescope

The design emphasizes the near to mid-infrared for several reasons:

-High-redshift (very early and distant) objects have their visible emissions shifted into the infrared, and therefore their light can be observed today only via infrared astronomy;

-Infrared light passes more easily through dust clouds than visible light;

-Colder objects such as debris disks and planets emit most strongly in the infrared;

-These infrared bands are difficult to study from the ground or by existing space telescopes such as Hubble.

NASA, ESA and CSA have collaborated on the telescope since 1996. ESA's participation in construction and launch was approved by its members in 2003 and an agreement was signed between ESA and NASA in 2007.

In exchange for full partnership, representation and access to the observatory for its astronomers, ESA is providing the NIRSpec instrument, the Optical Bench Assembly of the MIRI instrument, an Ariane 5 ECA launcher, and manpower to support operations.

The CSA provided the Fine Guidance Sensor and the Near-Infrared Imager Slitless Spectrograph and manpower to support operations.

Several thousand scientists, engineers, and technicians spanning 15 countries have contributed to the build, test and integration of the JWST.

A total of 258 companies, government agencies, and academic institutions participated in the pre-launch project; 142 from the United States, 104 from 12 European countries (including 21 from the U.K., 16 from France, 12 from Germany and 7 international), and 12 from Canada. Other countries as NASA partners, such as Australia, were involved in post-launch operation.

More information: NASA

The James Webb Space Telescope 

was specifically designed to see
the first stars and galaxies 

that were formed in the universe.

John M. Grunsfeld