The James Webb Space Telescope (JWST or "Webb") is a space telescope that is the successors to the Hubble Space Telescope. The JWST will provide improved infrared resolution and sensitivity over Hubble, and will enable a broad range of investigations across the fields of astronomy and cosmology, including observing some of the most distant events and objects in the universe, such as the formation of the first galaxies.
the JWST is developed by NASA with contributions from the European Space Agency and the Canadian Space Agency and is named for James E. Webb, who was the administrator of NASA from 1961 to 1968 and played an important role in the Apollo program. The estimated budget is over $10 billion USD.
THE WAY FAR BETTER THEN HUBBLE SPACE TELESCOPE
The primary mirror of the JWST, the Optical Telescope Element, is composed of eighteen 1.32-meter hexagonal mirror segments made of gold-plated beryllium which combine to create a 6.5-meter diameter mirror that is considerably larger than the Hubble's 2.4-meter mirror.
Hubble is able to observe in near ultraviolet , visible and near infrared spectra. the JWST will observe in a lower frequency range, from long-wavelength visible light through mid-infrared (0.6 to 28.3 μm), which will allow it to observe high redshift (electromagnetic radiation from object goes on increasing) objects that are too old and too distant for the Hubble to observe. The telescope must be kept very cold in order to observe in the infrared without interference. To protect this from sun a large sunshield made of silicon- and aluminum-coated Kapton (polyimide film) will keep its mirror and instruments below 50 K.
OPTICS OF JWST
JWST's primary mirror is a 6.5-meter-diameter gold-coated beryllium reflector with a collecting area of 25 sq.metre. The mirror is too large it cannot be carried as such by any existing launch vehicle. it has 18 segments and after launch it is assembled in space. After a initial configuration there will be a need of occasional updates to keep it in a optimal focus. The total number of mirror segments include
18 primary mirror, secondary, tertiary. it also includes fine steering mirrors and flight spare mirrors.
SCIENTIFIC INSTRUMENTS IN JWST
NIRcam (Near Infrared Camera)
It is an infrared imager that will have the spectral coverage ranging from the edge of visible 0.6 micrometre to near infrared 5 micrometre.
NIRspec (Near Infrared Spectrography)
It also perform spectroscopy over the same wavelength range. It was built by the European Space Agency. It is operable at three different modes : a low-resolution mode using a prism, an R~1000 multi-object mode and an R~2700 integral field unit or long-slit spectroscopy mode.
MIRI ( Mid-InfraRed Instrument )
It will measure the mid-to-long-infrared wavelength range from 5 to 27 micrometers. It contains both a mid-infrared camera and an imaging spectrometer.
FGS/NIRISS (Fine Guidance Sensor and Near Infrared Imager and Slitless Spectrograph)
It is used to stabilize the line-of-sight of the observatory during science observations. Measurements by the FGS are used both to control the overall orientation of the spacecraft and to drive the fine steering mirror for image stabilization.
SPACECRAFT BUS
The Spacecraft Bus is the primary support component of the James Webb Space Telescope, that hosts a multitude of computing, communication, propulsion, and structural parts, bringing the different parts of the telescope together. Along with the Sun shield, it forms the Spacecraft Element of the space telescope. The other two major elements of the JWST are the Integrated Science Instrument Module (ISIM) and the Optical Telescope Element (OTE). Region 3 of ISIM is also inside the Spacecraft Bus; region 3 includes ISIM Command and Data Handling subsystem and the MIRI cryocooler. It can able to support about 6.5 ton space telescope, while it itself weighs 350 kg. It is made primarily of graphite composite material.
The Spacecraft Bus is on the Sun-facing "warm" side and operates at a temperature of about 300 K. Everything on the Sun facing side must be able to handle the thermal conditions of JWST's halo orbit, which has one side in continuous sunlight and the other in the shade of the spacecraft sunshield.
It is expected to be launch on 30 march 2021. If it is successful then it will be very helpful for further space exploration.
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| image credit : NASA |
the JWST is developed by NASA with contributions from the European Space Agency and the Canadian Space Agency and is named for James E. Webb, who was the administrator of NASA from 1961 to 1968 and played an important role in the Apollo program. The estimated budget is over $10 billion USD.
THE WAY FAR BETTER THEN HUBBLE SPACE TELESCOPE
The primary mirror of the JWST, the Optical Telescope Element, is composed of eighteen 1.32-meter hexagonal mirror segments made of gold-plated beryllium which combine to create a 6.5-meter diameter mirror that is considerably larger than the Hubble's 2.4-meter mirror.
Hubble is able to observe in near ultraviolet , visible and near infrared spectra. the JWST will observe in a lower frequency range, from long-wavelength visible light through mid-infrared (0.6 to 28.3 μm), which will allow it to observe high redshift (electromagnetic radiation from object goes on increasing) objects that are too old and too distant for the Hubble to observe. The telescope must be kept very cold in order to observe in the infrared without interference. To protect this from sun a large sunshield made of silicon- and aluminum-coated Kapton (polyimide film) will keep its mirror and instruments below 50 K.
 |
| bottom view(sun facing side) image credit : wikipedia |
 |
| top view image credit : wikipedia |
OPTICS OF JWST
JWST's primary mirror is a 6.5-meter-diameter gold-coated beryllium reflector with a collecting area of 25 sq.metre. The mirror is too large it cannot be carried as such by any existing launch vehicle. it has 18 segments and after launch it is assembled in space. After a initial configuration there will be a need of occasional updates to keep it in a optimal focus. The total number of mirror segments include
18 primary mirror, secondary, tertiary. it also includes fine steering mirrors and flight spare mirrors.
SCIENTIFIC INSTRUMENTS IN JWST
NIRcam (Near Infrared Camera)
It is an infrared imager that will have the spectral coverage ranging from the edge of visible 0.6 micrometre to near infrared 5 micrometre.
NIRspec (Near Infrared Spectrography)
It also perform spectroscopy over the same wavelength range. It was built by the European Space Agency. It is operable at three different modes : a low-resolution mode using a prism, an R~1000 multi-object mode and an R~2700 integral field unit or long-slit spectroscopy mode.
MIRI ( Mid-InfraRed Instrument )
It will measure the mid-to-long-infrared wavelength range from 5 to 27 micrometers. It contains both a mid-infrared camera and an imaging spectrometer.
FGS/NIRISS (Fine Guidance Sensor and Near Infrared Imager and Slitless Spectrograph)
It is used to stabilize the line-of-sight of the observatory during science observations. Measurements by the FGS are used both to control the overall orientation of the spacecraft and to drive the fine steering mirror for image stabilization.
SPACECRAFT BUS
The Spacecraft Bus is the primary support component of the James Webb Space Telescope, that hosts a multitude of computing, communication, propulsion, and structural parts, bringing the different parts of the telescope together. Along with the Sun shield, it forms the Spacecraft Element of the space telescope. The other two major elements of the JWST are the Integrated Science Instrument Module (ISIM) and the Optical Telescope Element (OTE). Region 3 of ISIM is also inside the Spacecraft Bus; region 3 includes ISIM Command and Data Handling subsystem and the MIRI cryocooler. It can able to support about 6.5 ton space telescope, while it itself weighs 350 kg. It is made primarily of graphite composite material.
The Spacecraft Bus is on the Sun-facing "warm" side and operates at a temperature of about 300 K. Everything on the Sun facing side must be able to handle the thermal conditions of JWST's halo orbit, which has one side in continuous sunlight and the other in the shade of the spacecraft sunshield.
It is expected to be launch on 30 march 2021. If it is successful then it will be very helpful for further space exploration.
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