|
JWST Telescope Alignment Evaluation Image Labeled
The James Webb Space Telescope (JWST) is a space telescope designed to conduct infrared astronomy. As the largest telescope in space, it is equipped with high-resolution and high-sensitivity instruments, allowing it to view objects too old, List of the most distant astronomical objects, distant, or faint for the Hubble Space Telescope. This enables investigations across many fields of astronomy and cosmology, such as observation of the Population III star, first stars and the Galaxy formation and evolution, formation of the first galaxies, and detailed atmospheric characterization of potentially habitable exoplanets. Although the Webb's mirror diameter is 2.7 times larger than that of the Hubble Space Telescope, it produces images of comparable optical resolution, resolution because it observes in the longer-wavelength infrared spectrum. The longer the wavelength of the spectrum, the larger the information-gathering surface required (mirrors in the infrared spectrum or antenna a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Observatory
A space telescope (also known as space observatory) is a telescope in outer space used to observe astronomical objects. Suggested by Lyman Spitzer in 1946, the first operational telescopes were the American Orbiting Astronomical Observatory, OAO-2 launched in 1968, and the Soviet Orion (space telescope), Orion 1 ultraviolet telescope aboard space station Salyut 1 in 1971. Space telescopes avoid several problems caused by the atmosphere, including the absorption or scattering of certain wavelengths of light, obstruction by clouds, and distortions due to atmospheric refraction such as twinkling. Space telescopes can also observe dim objects during the daytime, and they avoid light pollution which Observatory#Ground-based observatories, ground-based observatories encounter. They are divided into two types: Satellites which map the entire sky (astronomical survey), and satellites which focus on selected astronomical objects or parts of the sky and beyond. Space telescopes are distinct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halo Orbit
A halo orbit is a periodic, non-planar orbit associated with 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. Definition and history Robert W. Farquhar first used the name " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telemetry
Telemetry is the in situ collection of measurements or other data at remote points and their automatic transmission to receiving equipment (telecommunication) for monitoring. The word is derived from the Greek roots ''tele'', 'far off', and ''metron'', 'measure'. Systems that need external instructions and data to operate require the counterpart of telemetry: telecommand. Although the term commonly refers to wireless data transfer mechanisms (e.g., using radio, ultrasonic, or infrared systems), it also encompasses data transferred over other media such as a telephone or computer network, optical link or other wired communications like power line carriers. Many modern telemetry systems take advantage of the low cost and ubiquity of GSM networks by using SMS to receive and transmit telemetry data. A ''telemeter'' is a physical device used in telemetry. It consists of a sensor, a transmission path, and a display, recording, or control device. Electronic devices are widely u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S Band
The S band is a designation by the Institute of Electrical and Electronics Engineers (IEEE) for a part of the microwave band of the electromagnetic spectrum covering frequencies from 2 to 4 gigahertz (GHz). Thus it crosses the conventional boundary between the UHF and SHF bands at 3.0 GHz. The S band is used by airport surveillance radar for air traffic control, weather radar, surface ship radar, and some communications satellites, particularly satellites used by NASA to communicate with the Space Shuttle and the International Space Station. The 10 cm radar short-band ranges roughly from 1.55 to 5.2 GHz. India's regional satellite navigation network ( IRNSS) broadcasts on 2.483778 to 2.500278 GHz. The S band also contains the 2.4–2.483 GHz ISM band, widely used for low power unlicensed microwave devices such as cordless phones, wireless headphones (Bluetooth), garage door openers, keyless vehicle locks, baby monitors as well as for medical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sunshield (JWST)
The James Webb Space Telescope (JWST) Spacecraft thermal control#Sun shield, sunshield is a passive Spacecraft thermal control, thermal control system deployed post-launch to shield the telescope and instrumentation from the light and heat of the Sun, Earth, and Moon. By keeping the telescope and instruments in permanent shadow, it radiative cooling, allows them to cool to their design temperature of . Its intricate deployment was successfully completed on January 4, 2022, ten days after launch, when it was more than away from Earth. The JWST sunshield is about , roughly the size of a tennis court, and is too big to fit in any existing rocket. Therefore, it was folded up to fit within the fairing of the launch rocket and was deployed post-launch, unfolding five layers of metal-coated plastic. The first layer is the largest, and each consecutive layer decreases in size. Each layer is made of a thin (50 microns for the first layer, 25 microns for the others) Kapton membrane coat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spacecraft Bus (JWST)
The spacecraft bus is a carbon fibre box that houses systems of the telescope and so is the primary support element of the James Webb Space Telescope, launched on . It hosts a multitude of computing, communication, propulsion, and structural components. The other three elements of the JWST are the Optical Telescope Element (OTE), the Integrated Science Instrument Module (ISIM), and the Sunshield (JWST), sunshield. Region 3 of ISIM is also inside the spacecraft bus. Region 3 includes the ISIM Command and Data Handling subsystem and the MIRI (Mid-Infrared Instrument), Mid-Infrared Instrument (MIRI) cryocooler. The spacecraft bus must structurally support the 6.5 ton space telescope, while weighing only . It is made primarily of graphite composite material. It was assembled by Northrop Grumman in Redondo Beach, California by 2015, and then it had to be integrated with the rest of the space telescope leading up to its planned 2018 launch. The bus can provide pointing precision of one m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Telescope Element
Optical Telescope Element (OTE) is a sub-section of the James Webb Space Telescope, a large infrared space telescope launched on , consisting of its Primary mirror, main mirror, secondary mirrors, the framework and controls to support the mirrors, and various thermal and other systems. The OTE collects the light and sends it to the science instruments in Webb's Integrated Science Instrument Module. The OTE has been compared to being the "eye" of the telescope and the backplane of it to being the "Vertebral column, spine". The primary mirror is a tiled assembly of 18 hexagonal elements, each from flat to flat. This combination yields an effective aperture of and a total collecting surface of . Secondary mirrors complete anastigmatic imaging optics with effective 20 focal ratio and focal length of . The main three-mirror telescope is a Three-mirror anastigmat#Korsch telescope, Korsch-type design, and it feeds into the Aft Optics Subsystem (part of OTE), which in turn feeds int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integrated Science Instrument Module
Integrated Science Instrument Module (ISIM) is a component of the James Webb Space Telescope, a large international infrared space telescope launched on . ISIM is the heart of the JWST, and holds the main science payload which includes four science instruments and the fine guidance sensor. ISIM is the spacecraft chassis and instruments that take the light from the main mirror and convert that into the science data that is then sent back to Earth. The other two major sections of the JWST are the Optical Telescope Element (OTE) (mirrors and their structure) and the Spacecraft Element (SE), which includes the spacecraft bus and sunshield. ISIM has a mass of 1400 kg (3086 lb), about 23% of the mass of the JWST. The infrared camera instrument integrated with ISIM passed its thermal tests in early 2016. ISIM underwent intense thermal cold testing in late 2015 to early 2016. NIRcam is extremely important to JWST, because it is not only a sensitive infrared camera, but it is also u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NIRSpec
The NIRSpec (Near-Infrared Spectrograph) is one of the four scientific instruments flown on the James Webb Space Telescope (JWST). The JWST is the follow-on mission to the Hubble Space Telescope (HST) and is developed to receive more information about the origins of the universe by observing infrared light from the first stars and galaxies. In comparison to HST, its instruments will allow looking further back in time and will study the so-called Dark Ages during which the universe was opaque, about 150 to 800 million years after the Big Bang. The NIRSpec instrument is a multi-object spectrograph and is capable of simultaneously measuring the near-infrared spectrum of up to 100 objects like stars or galaxies with low, medium and high spectral resolutions. The observations are performed in a 3 arcmin × 3 arcmin field of view over the wavelength range from 0.6 μm to 5.0 μm. It also features a set of slits and an aperture for high contrast spectroscopy of individual sources, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NIRCam
NIRCam (Near-InfraRed Camera) is an instrument aboard the James Webb Space Telescope. It has two major tasks, as an imager from 0.6 to 5 micrometre, μm wavelength, and as a wavefront sensor to keep the 18-section mirrors functioning as one. In other words, it is a camera and is also used to provide information to align the 18 segments of the primary mirror. It is an infrared camera with ten Mercury cadmium telluride, mercury-cadmium-telluride (HgCdTe) detector arrays, and each array has an array of 2048×2048 pixels. The camera has a field of view of 2.2×2.2 arcminutes with an angular resolution of 0.07 arcseconds at 2 μm. NIRCam is also equipped with coronagraphs, which helps to collect data on exoplanets near stars. It helps with imaging anything next to a much brighter object, because the coronagraph blocks that light. NIRCam is housed in the Integrated Science Instrument Module (ISIM). It is connected to the ISIM mechanically with a system of kinematic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MIRI (Mid-Infrared Instrument)
MIRI, or the Mid-Infrared Instrument, is an instrument on the James Webb Space Telescope. MIRI is a camera and a spectrograph that observes mid to long infrared radiation from 5 to 28 microns. It also has coronagraphs, especially for observing exoplanets. Whereas most of the other instruments on Webb can see from the start of near infrared, or even as short as orange visible light, MIRI can see longer wavelength light. MIRI uses silicon arrays doped with arsenic to make observations at these wavelengths. The imager is designed for wide views but the spectrograph has a smaller view. Because it views the longer wavelengths it needs to be cooler than the other instruments (see Infrared astronomy), and it has an additional cooling system. The cooling system for MIRI includes a pulse tube precooler and a Joule-Thomson loop heat exchanger. This allowed MIRI to be cooled down to a temperature of 7 kelvins during operations in space. MIRI was built by the MIRI Consortium, a group t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fine Guidance Sensor And Near Infrared Imager And Slitless Spectrograph
Fine Guidance Sensor and Near Infrared Imager and Slitless Spectrograph (FGS-NIRISS) is an instrument on the James Webb Space Telescope (JWST) that combines a Fine Guidance Sensor and a science instrument, a near-infrared imager and a spectrograph. The FGS/NIRISS was designed by the Canadian Space Agency (CSA) and built by Honeywell as part of an international project to build a large infrared space telescope with the National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA). FGS-NIRISS observes light from the wavelengths of 0.8 to 5.0 microns. The instrument has four different observing modes. Physically the FGS and NIRISS are combined, but optically they are separate with the FGS being used by the telescope to point it, whereas NIRISS is an independent science instrument. The spectroscopic mode is capable of doing exoplanet spectroscopy. The detector for NIRISS is a 2048 × 2048 pixel mercury cadmium telluride (HgCdTe) array, where each pixel is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
