Primary Mirror
The primary mirror part of the OTE(Optical Telescope Element) is the main area where vital information can be gathered ranging from pictures of faraway galaxies to our asteroid belt. A massive engineering feat with a width of a whopping 6.5 meters and an area of 25m2, approximately 6.25 times of the area used in the Hubble Space telescope.
The primary mirror is made up of Beryllium, a lightweight and highly durable material suitable for the confines of space coated in one gold ball, weighing 48.2 grams spread over 25m2. Gold is not the optimal material for reflectivity in the visible light spectrum for its reflectivity is lower in the beginning of the spectrum. Yet, it’s an extremely effective reflective surface for infrared light, enabling the Infrared telescope: James Webb to relay pictures about events which have occurred approximately 13.5 billion years ago.
In addition, the primary mirror is made up of 18 hexagonal segments, allowing the concave structure to reflect every possible Infrared wave to the Secondary mirror. Finally, the James Webb Space Telescope can adject each mirror’s focus and curvature via motors behind each hexagonal structure to achieve the most accurate image of the universe possible.
Secondary Mirror
The secondary mirror is the small round convex mirror located at the end of long booms. These booms keep folded during the launch. Secondary mirrors in the form of optically flat diagonal mirrors re-direct the light path in designs such as Newtonian reflectors. Its task is to concentrate the light collected by the gold-coated primary mirror into an opening at the center.
The Trim Flap
The Trim Flap present on the James Webb Space Telescope enables spacecraft to counter the Solar pressure exerted from the sun, where the pressure of photons hitting the telescope forces it out of position. This enables engineers to invest less fuel from the spacecraft’s fuel reserves into position adjustment, hence allowing the JWST to last and operate longer while maintaining a stable bearing in Lagrange Point 2.
The ISIM
(Integrated Science Instrument Module)
-
The ISIM is the crucial payload of the James Webb Space Telescope housing 4 main elements which would make up the frontier of human discovery. Firstly, the Near Infrared Camera, or NIRCam is the Webb’s primary imager which covers and aspect of the Infrared range: from 0.6 to 5 microns. This enables astronomers to take barely visible pictures of objects obscured by other light sources such as stellar systems and objects within them like Jupiter and Europa.
-
Secondly, the Near Infrared Spectrograph or NIRSpec will also be operating from a range of 0.6 to 5 microns and will be used to analyse the light radiated from an object into a spectrum, offering crucial information about the substance’s properties such as mass, temperature, and chemical composition.
-
Thirdly, the Mid- Infrared Instrument is one of the most vital parts of the James Webb Space telescope for it views light in the mid-infrared spectrum, analysing at a range from 5 to 28 microns and operates at just 7 Kelvin. 7 degrees from absolute zero, the coldest temperature in the entire universe. The MIRI is the jewel in the Webb’s arsenal for it withholds astonishing and breath-taking pictures of the universe we come to love. Finally, the Fine Guidance Sensor or FGS serves as the pointer to the telescope, enabling the marvel of engineering to be aimed to a specific area and take precise and accurate pictures.
The James Webb Sunshield
-
Webb has two sides, divided by its sun shield: a hot side facing the Sun and Earth and a cold side facing out into space, away from the Sun and Earth.
-
The James Webb Space Telescope will primarily observe infrared light from faint and very distant objects. The telescope must be extremely cold to detect those faint heat signals.
-
protects the telescope from external sources of light and heat (like the Sun, Earth, and Moon) as well as from heat emitted by the observatory itself
-
(SIZE)5-layer, tennis court-sized sun shield that acts like a parasol providing shade
-
This sun shield will always be between the Sun/Earth/Moon and the telescope. It can be positioned this way because JWST will be orbiting the Sun 1.5 million kilometres away from (but approximately in line with) the Earth.
-
The sun shield will allow the telescope to cool down to a temperature below 50 Kelvin (-370°F, or -223°C) by passively radiating its heat into space.
Solar array
-
The JWST consists of about five solar panels to power the enormous telescope, connected by hinges onto the folding launch vehicle.
-
At 37.1 feet long and 24 feet wide, the solar-powered array provides an average of 2,000 watts of electrical power for the life of the mission.
-
These one-of-a-kind panels can reach up to around 27 to 30% efficiency, while the commercial, more conventional ones have less than 20%.
-
Another plus point is that the JWST does not see any eclipse, so that the solar panels can generate power at all times for the entirety of the space mission.
Star Trackers
-
Use guide stars for coarse pointing of the telescope. The star tracker data enables the alignment and control system to point the telescope so that the target appears in the field of view. Once an observation is started, the Fine Guidance Sensors can compensate for small drifts in the observatory's alignment and help the telescope maintain its good pointing.
Earth Pointing Antenna
-
The Earth-pointing antenna sends science data back to earth and receives commands from NASA's Deep Space Network.
-
Humans will use this antenna to send at least 28.6 Gigabytes of science data from the observatory twice daily.
-
According to NASA, the JWST is 1.5 million kilometers away, about five light seconds, and the Earth-pointing antenna facilitates data transfer through this distance.