R & D Background
Beginning in 1996, NASA bidding to the national nation, looking for this extremely precise spatial telescope plan. The four institutions of the bid are: NASA / Gordi Aerospace Center, US TRW, famous Locks Martin and the US Ball Airlines Cosmo. Finally, TRW has been strictly filtered and finally won.
"James - Weber" name is taken from the Second Director of NASA, James Weber, who is a US Aviation Administration (NASA) leader, opened new Chapter, including exploration of moon and "Apollo" moon plan. Therefore, "James Weber" was born, and he hopped people's hopes. Compared with "Hubble", "James Weber" is larger, more precise, can survey more space! It is three times the "Hubble Space Telescope", but the quality is only about half of Hubble. It is a telescope without a lens barrel.
James Web telescope is the successor of the Hubble Space Telescope, which will become the next generation space observatory. It will be the most powerful space telescope built in history, which will provide images of the first galaxies formed in the universe and explore the planets around the distant star. This is a joint project of NASA, the European Space Agency and the Canadian Space Agency.
Development History
According to the original plan, Weber telephoto mirror should be launched in 2014, but postpon delay due to budget.
In September 2017, the US Savigation Bureau said that the launch window of James Weber Space Telescope will be delayed from October 2018 from March to June 2019. The declaration explained that the volume and complexity of the Weber telescope and its shading have exceed most detectors. For example, only more than 100 disclosure devices are installed, and the vibration test is used for a longer period, so it is postponed to the spring of 2019 It is a Ruya Kuru Space Center to launch an emission with the Aliana 5 rocket in Europe.
On March 28, 2018, NASA announced that Weber did not launch a launch before 2020.
May 6, 2018, the latest launch date of JWST has been postponed until 2020 by a series of technical issues.
June 29, 2018, according to foreign media reports, Hubble Telescope's "Renewable" James Weber Telescope will postpone the first March 30, 2021.
Mirror System
Main Mirror
The mirror system of James Weber Telescope includes primary mirror, secondary mirror and three mirrors. Although the secondary mirror and three mirrors in size are very characteristic, the expensive main mirror is the most complicated structure, and many mirrors are spliced.
Mirror System and Precision Fliring Mirror (FSM) is developed by Bauer Aerospace Technology, which is the main contractor of Nobi Give "Optical Technology and Light Mirror System". "Weber" main mirror diameter is as high as 6.5 meters, and it is absolutely considerable in the Tianji telescope.
The diameter of the primary mirror is larger than the rocket that is used. The primary mirror is divided into 18 hexagonal lenses, and these lenses are launched under the control of high-precision micro motors and wavefront sensors. However, this method will not be the same as the Kaike telescope, and it is necessary to continue to adjust the mirror according to the active optical optical optical direction as the ground telescope, so that James Wyber Space Telescope will not be in addition to the initial configuration. There are too many changes.
The mirror of the primary mirror also also forms a hexagonal shape, the concentrating portion and the mirror are exposed to the outside, which is easy to let people think of the antenna of the radio telescope. In addition, its main body is not tonic, but is expanded under the main mirror.
mirror substrate
The mirror substrate allows all mirrors to be spliced into a traditional mirror in the traditional sense. The substrate has a thickness of about 5 cm, and the "front" reflective surface is highly polished, "the" surface "structure is superminated to a" egg type "structure than the solid structure.
The surface roughness of the reflecting surface is less than 20 nm, and a pure gold film plated is also in order to improve its reflection infrared light. The choice of beryllium material is due to its extremely high rigidity and lightweight characteristics, it is not easy to change in the "Weber" extremely cold operating temperature.
Beryllium Transformer Parts
The other side of the beryllium substrate is mounted on a triangular, egg-type berylli force component. Each force is about 60 cm long and 30 cm wide, which can be used to share loads from the underlying structure to reduce mirror distortion.
Beryllium triangle frame
Beryllium triangle frame (BDF) is the main intermediate structure of 18 mirrors, with a triangular architecture width of about 76.2cm, connected in the actuator and mirror, Between the substrate or force part.
Maker
The actuator is a fine structure composed of precision motor and gears for moving and adjusting the surface shape of the mirror. The actuator can accurately arrange 18 mirrors, like a side of the universe to collectively imaging.
18 block mirror each contains 6 sets of mobile and rotating actuators, all mirrors can use the actuator to arrange a huge mirror. In addition, each kioscope is equipped with a special actuator, while connecting the side of the lens directly, the other side is connected to the edge of the lens through long, thin beryllium structure. Each actuator can make 18 mirrors with the identical "curvature center" to ensure their focus coincidence.
These mirror actuators are one of the many new inventions of Weber. They are capable of impovering optimal optical properties through nanoscale microcarcles. In addition, these actuators must operate at extreme "refrigeration" temperatures that are only 20 degrees higher than absolute zero.
When "Weber" departs in space and cools to operating temperatures, the engineers of the ground station will send instructions to all actuators to adjust all mirrors, which is two months. Subsequently, once "Weber" began to fully operate and scientifically observed, a mirror tuning work was conducted every 10 to 14 days. With this new technology, "Weber" will become the first Tianquity Observatory that actively controls the mirror.
Interface Flexible Parts
The Base Plate Adjustment Part (BIF) interface connects the main mirror to the telescope floor, the bottom plate supports 18 schniques of the main mirror. Precision machined flexible components are like exquisite springs, which can withstand thermal expansion of thermal expansion caused by temperature changes from room temperature to zero under 190 degrees.
In addition to these connected to the bottom plate, there are many flexible components on each membram.
Shading Device
James Weber Space Telescope's SPF value reaches 1 million, can isolate any suspicious external heat sources to ensure calm observation environments. The engineer of NASA has launched the test of the giant sunshade device of James Weber Space Telescope, progressed smoothly.
Giant Shading Device is very large, close to the size of a tennis court, and multi-layer structure, NASA conducts testing in clean room located in Nosrop Gall, California . The giant sunshade device not only needs to block the sunlight, but also have a very accurate positioning device. All components on the telescope are installed on a giant shade device, and the effects of sunlight on the observation can be installed. William Oaks from the Center of NASA Gotoder, believes that the giant shading device is a five-layer structure, like a huge sunshade fan, can be transmitted from the sun from the sun.
The main task of the James Weber Space telescope is to investigate the residual infrared evidence of the big explosive theory (the universe microwave background radiation), that is, the initial state of the universe can be seen today. To reach this, it is equipped with high-sensitivity infrared sensors, spectroscopes, etc. In order to facilitate observation, the body should be able to withstand the limit of low temperature, but also avoid the sun and the globe. To this end, the James Weber Space Telescope comes with foldable shading to shield a light source that interferes. Because it is in the Lagrangian point, the earth and the sun are always in the same relative position in the perspective of the telescope, and the visor can also make the light-shielding board do the effect. Overall parameters
Agency: NASA, ESA, CSA
Band: infrared
Track height: 1.5 million kilometers (second Lagrangian point)
Track period: 1 year
Book time: 2018
Falling period: 2016 - 2021
Quality: 6,200 kg
alias: New Generation Space Telescope, NGST)
James - Weber (3) < / P> Optical System
Form: Different, Newon
Call: 6.5 m
Conveutrotic Area: About 25 meters
Observing Device
Nircam near infrared camera
NIRSPEC near-infrared spectroscope
mir in infrared device
FGS fine laterally sensor
R & D risk
Weber Telescope is one of the most complex projects in the history of NASA, and its risk is huge, and "Hubble Space Telescope" is not the same, "James Weber" Because it is too far from the earth, you can't send astronauts to carry out maintenance, it is perfect for the design and manufacturing, otherwise it will be lost! Unknown issues may also be found in the future system integration test, once the test is difficult, it will lead to delay. If the Weber telescope can go smoothly into the orbit, it can demonstrate its powerful observation.