Now is a good time to talk about James webb Space Telescope.

Oct 10, 2021
3
0
10
James webb space telescope is very well known for its capabilities and at the same time it is also very well known for its delays. People have been waiting for its launch for nearly a decade now. Finally it is on its way to get launched. It has now reached French Guiana. Now it is a good time to recall about its capabilities and the gains that NASA is going to make after it will be launched.
 
Jan 27, 2020
243
85
680
At only 5 degrees north of the equator, the rockets launched in French Guiana can benefit from the ‘slingshot effect’ due to the speed of Earth’s rotation, increasing their performance as they already travel at over 300 m/s when they lift off. Also, an open ocean towards the east and north offers a large range of possible launch trajectories away from populated areas.

This region also has a very low risk of cyclones or earthquakes which is important when such delicate operations are taking place.

Europe’s powerful and highly reliable heavy-lift workhorse, Ariane-5, has an excellent track record spanning more than 100 launches and three decades. Ariane 5’s ample fairing, 5.4 m diameter and 17 m high, provides enough space for Webb’s folded spacecraft components, sunshield, and mirrors.

Ariane 5 is well suited for science satellites with the proven capability to send missions to the second Lagrange Point (L2). Ariane 5 will release Webb directly on a path towards L2 (Lagrangian Point 2)* on which it will continue for four weeks, eventually arriving at L2 which is four times farther away than the Moon is from Earth.

Webb-and-Ariane-5-Perfect-Fit.jpeg
Webb and Ariane 5: a fit made perfect. Ariane 5 has been customized to accommodate all the specific requirements of the Webb mission. Credit: ESA

A few customized features make Ariane 5 a perfect fit for Webb. These include the adaptation of venting ports at the base of the fairing which will be forced fully open during the flight. The fairing – the rocket’s nose cone – will protect Webb from the acoustics at liftoff and during its journey through Earth’s atmosphere. Its venting ports will enable extremely smooth depressurization of the fairing from ground pressure to vacuum during the flight.

Then, to avoid overheating of any elements of Webb, Ariane 5 will perform a specially developed rolling maneuver to ensure that all parts of the satellite will be equally exposed to the sun.

An extra battery will provide power for a boost to the upper stage after release of the telescope, safely distancing it from Webb.

“Webb is an excellent example of international teamwork and cooperation. We welcome Webb and our partners to Europe’s Spaceport in French Guiana to continue this adventure towards a thrilling liftoff on board Ariane 5 and to sharing the many Webb science breakthroughs to come!” commented Daniel Neuenschwander, ESA Director of Space Transportation.

Working with partners, ESA was responsible for the development and qualification of Ariane 5 adaptations for the Webb mission and for the procurement of the launch service.

Webb is an international partnership between NASA, the European Space Agency (ESA) and the Canadian Space Agency (CSA).

See: https://scitechdaily.com/10-billion-webb-space-telescope-arrives-at-europes-spaceport/
  1. NASA’s Webb Space Telescope Arrives at Europe's Spaceport in French Guiana
    Mike O'Neill, SciTechDaily, 2021
  2. James Webb Space Telescope’s Journey to Space [Video]
    Mike ONeill, SciTechDaily, 2021
  3. How To Ship the World’s Largest and Most Powerful Space Telescope 5,800 Miles Across the Ocean
    Mike ONeill, SciTechDaily, 2021
  4. A European Push to the Moon and Beyond
    Mike ONeill, SciTechDaily, 2021
  5. Final Piece of Rocket Hardware Added to Artemis I Stack
    Mike ONeill, SciTechDaily, 2021
  6. NASA readies James Webb space telescope for December launch
    by NASAs Goddard Space Flight Center, Phys.org, 2021
  7. Webb completes testing and prepares for trip to Europe's Spaceportby European Space Agency, Phys.org, 2021
  8. Galileo satellites arrive at Europe's Spaceportby European Space Agency, TechXplore.com, 2021
  9. Ariane 5 Lifts Off, Misses Ideal OrbitScience, 1997Second Chance for ClusterScience, 1997
See: https://jwst.nasa.gov/content/observatory/instruments/fgs.html

See: https://jwst.nasa.gov/content/observatory/sunshield.html

* L2 is the farthest lagrange point, and it is intuitive to think that placing any satellite here would orbit the Sun slower than Earth does because it is farther away from the Sun, but that is not the case because of its nature as a Lagrange point. Points like L2 are of special importance because they act as “parking” spots in space — placing an object like a satellite at these points would cause it to orbit at the same pace as that of Earth so communications with that object would be comparatively easier. Furthermore, keeping it synchronous with Earthly time is also not a difficult problem.

There is, however, a catch to this point — L2. It is not stable over time, so an object located at this point is not certain to remain at there for long periods of time, but instead there is a high chance of that object moving out of these points and into a regular orbit. Artificial stability mechanisms, like thrusters, are needed to maintain the object’s position at L2.

L2-point.jpeg
The Sun-Earth Second Lagrangian point, or L2, is one of five places orbiting spacecraft can remain stable relative to the Sun and Earth. European Space Agency

** Fine Guidance Sensor (FGS) allows Webb to point precisely, so that it can obtain high-quality images. The Near Infrared Imager and Slitless Spectrograph part of the FGS/NIRISS will be used to investigate the following science objectives: first light detection, exoplanet detection and characterization, and exoplanet transit spectroscopy.

FGS/NIRISS has a wavelength range of 0.8 to 5.0 microns, and is a specialized instrument with three main modes, each of which addresses a separate wavelength range. FGS is a "guider," which helps point the telescope.

Screen Shot 2021-10-16 at 3.28.39 PM.png
FGS/NIRISS was built by the Canadian Space Agency.

See: https://jwst.nasa.gov/content/observatory/instruments/fgs.html

Finally, after solving a plethora of problems—delicate propulsion valves damaged by an improper cleaning solvent, loose screws (70 of them!) that came off during a shake test—that have cost $600 million and an 18-month delay and, of course, the arrival of the Covid-19 pandemic. Cumulatively, the project has now been delayed by years, at a cost of more than $9.6 billion. And two of the missing screws are still unaccounted for.

At L2 and1 million miles beyond the Earth’s orbit, further than any other Earth centered satellite, the Webb telescope can finally observe the deepest corners of the universe. There it will unfurl a sunshield to protect the special sensors that can detect images giving off the faint glow of far infrared light. From its perch in space, the telescope will be able to see the universe’s most distant objects, including stars that formed right after the Big Bang.

The sunshield 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. The near-infrared instruments (NIRCam, the Near Infrared Camera; NIRSpec, the Near Infrared Spectrometer; and the FGS/NIRISS**) will work at about 39 K (-389°F, -234°C) through a passive cooling system. The mid-infrared instrument (MIRI) will work at a temperature of 7 K (-447°F, -266°C), using a helium refrigerator, or cryocooler system. In addition to providing a cold environment, the sunshield also provides a thermally stable environment which is essential for maintaining proper alignment of the primary mirror segments as the telescope changes its orientation with the Sun.

Finally, after years of set backs, billions of dollars in cost overruns and lost screws, the James Webb telescope has finally arrived at the European Space Agency launch location in French Guiana, where it will soon become that same fire in the sky, Odin's sword, the description Wernher von Braun used to describe the first successful launch of the V-2 rocket at Peenemunde on October 3, 1942, during the Battle of Stalingrad.
Hartmann352
 
Last edited:
Jan 27, 2020
243
85
680
Arianespace operates a family of rockets at Europe’s Spaceport: Ariane 5, Vega, and Soyuz. This launch site is surrounded by jungle and covers 690 km2. It is an ideal location for launching rockets for several reasons.

First, at only 5 degrees north of the equator, the rockets launched here can benefit from the ‘slingshot effect’ due to the speed of Earth’s rotation, increasing their performance as they already travel at over 300 m/s when they lift off. Also, an open ocean towards the east and north offers a large range of possible launch trajectories away from populated areas.

Finally, this region has a very low risk of cyclones or earthquakes which is important when such delicate operations are taking place.

Europe’s powerful and highly reliable heavy-lift workhorse has an excellent track record spanning more than 100 launches and three decades. Ariane 5’s ample fairing, 5.4 m diameter and 17 m high, provides enough space for Webb’s folded spacecraft components, sunshield, and mirrors.

Ariane 5 is well suited for science satellites with proven capability to send missions to the second Lagrange Point (L2). Ariane 5 will release Webb directly on a path towards L2 (Lagrangian Point 2)* on which it will continue for four weeks, eventually arriving at L2 which is four times farther away than the Moon is from Earth.

View attachment 1557
Webb and Ariane 5: a fit made perfect. Ariane 5 has been customized to accommodate all the specific requirements of the Webb mission. Credit: ESA

A few customized features make Ariane 5 a perfect fit for Webb. These include the adaptation of venting ports at the base of the fairing which will be forced fully open during the flight. The fairing – the rocket’s nose cone – will protect Webb from the acoustics at liftoff and during its journey through Earth’s atmosphere. Its venting ports will enable extremely smooth depressurization of the fairing from ground pressure to vacuum during the flight.

Then, to avoid overheating of any elements of Webb, Ariane 5 will perform a specially developed rolling maneuver to ensure that all parts of the satellite will be equally exposed to the sun.
An extra battery will provide power for a boost to the upper stage after release of the telescope, safely distancing it from Webb.

“Webb is an excellent example of international teamwork and cooperation. We welcome Webb and our partners to Europe’s Spaceport in French Guiana to continue this adventure towards a thrilling liftoff on board Ariane 5 and to sharing the many Webb science breakthroughs to come!” commented Daniel Neuenschwander, ESA Director of Space Transportation.

Working with partners, ESA was responsible for the development and qualification of Ariane 5 adaptations for the Webb mission and for the procurement of the launch service.

Webb is an international partnership between NASA, the European Space Agency (ESA) and the Canadian Space Agency (CSA).

See: https://scitechdaily.com/10-billion-webb-space-telescope-arrives-at-europes-spaceport/
  1. NASA’s Webb Space Telescope Arrives at Europe's Spaceport in French Guiana
    Mike O'Neill, SciTechDaily, 2021
  2. James Webb Space Telescope’s Journey to Space [Video]
    Mike ONeill, SciTechDaily, 2021
  3. How To Ship the World’s Largest and Most Powerful Space Telescope 5,800 Miles Across the Ocean
    Mike ONeill, SciTechDaily, 2021
  4. A European Push to the Moon and Beyond
    Mike ONeill, SciTechDaily, 2021
  5. Final Piece of Rocket Hardware Added to Artemis I Stack
    Mike ONeill, SciTechDaily, 2021
  6. NASA readies James Webb space telescope for December launch
    by NASAs Goddard Space Flight Center, Phys.org, 2021
  7. Webb completes testing and prepares for trip to Europe's Spaceportby European Space Agency, Phys.org, 2021
  8. Galileo satellites arrive at Europe's Spaceportby European Space Agency, TechXplore.com, 2021
  9. Ariane 5 Lifts Off, Misses Ideal OrbitScience, 1997Second Chance for ClusterScience, 1997
See: https://jwst.nasa.gov/content/observatory/instruments/fgs.html

See: https://jwst.nasa.gov/content/observatory/sunshield.html

Finally, after solving a plethora of problems—delicate propulsion valves damaged by an improper cleaning solvent, loose screws (70 of them!) that came off during a shake test—that have cost $600 million and an 18-month delay and, of course, the arrival of the Covid-19 pandemic. Cumulatively, the project has now been delayed by years, at a cost of more than $9.6 billion. And two of the missing screws are still unaccounted for.

But, at L2 and1 million miles beyond the Earth’s orbit, further than any other Earth centered satellite, the Webb telescope can observe the deepest corners of the universe. There it will unfurl a sunshield to protect the special sensors that can detect images giving off the faint glow of far infrared light. From its perch in space, the telescope will be able to see the universe’s most distant objects, including stars that formed right after the Big Bang.

The sunshield 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. The near-infrared instruments (NIRCam, the Near Infrared Camera; NIRSpec, the Near Infrared Spectrometer; and the FGS/NIRISS**) will work at about 39 K (-389°F, -234°C) through a passive cooling system. The mid-infrared instrument (MIRI) will work at a temperature of 7 K (-447°F, -266°C), using a helium refrigerator, or cryocooler system.

In addition to providing a cold environment, the sunshield provides a thermally stable environment. This is essential to maintaining proper alignment of the primary mirror segments as the telescope changes its orientation to the Sun.

Finally, after years of set backs, billions of dollars in cost overruns and lost screws, the James Webb telescope has finally arrived at the European Space Agency launch location in French Guiana, where it will soon become that fire in the sky, that blazing 'Odin's sword' which von Braun so vividly described when the first V-2 flew at Peenemunde in October of 1942, while the Battle of Stalingrad raged and the bodies stank.
Hartmann352

* L2 is the farthest lagrange point, and it is intuitive to think that placing any satellite here would orbit the Sun slower than Earth does because it is farther away from the Sun, but that is not the case because of its nature as a Lagrange point. Points like L2 are of special importance because they act as “parking” spots in space — placing an object like a satellite at these points would cause it to orbit at the same pace as that of Earth so communications with that object would be comparatively easier. Furthermore, keeping it synchronous with Earthly time is also not a difficult problem.

There is, however, a catch to this point — L2. It is not stable over time, so an object located at this point is not certain to remain at there for long periods of time, but instead there is a high chance of that object moving out of these points and into a regular orbit. Artificial stability mechanisms, like thrusters, are needed to maintain the object’s position at L2.

View attachment 1558
The Sun-Earth Second Lagrangian point, or L2, is one of five places orbiting spacecraft can remain stable relative to the Sun and Earth. European Space Agency

** Fine Guidance Sensor (FGS) allows Webb to point precisely, so that it can obtain high-quality images. The Near Infrared Imager and Slitless Spectrograph part of the FGS/NIRISS will be used to investigate the following science objectives: first light detection, exoplanet detection and characterization, and exoplanet transit spectroscopy.

FGS/NIRISS has a wavelength range of 0.8 to 5.0 microns, and is a specialized instrument with three main modes, each of which addresses a separate wavelength range. FGS is a "guider," which helps point the telescope.

View attachment 1559
FGS/NIRISS was built by the Canadian Space Agency.
 
Mar 4, 2020
373
45
730
It will probably take another year. They still have to place it, and calibrate it. I'm sure early calibration images will be released.

Bout a year for the instrument for work full spec. Assuming no problems.

Those images will pose many, many new questions.

Can't wait.

We need a full em spectrum from the cosmos.
 
Mar 4, 2020
373
45
730
I'm curious to see the cloud regions and densities thru out our Milky Way. And where the clouds are, with respect to our spirals. Wouldn't it be neat to see some star trails thru dust clouds. And of course we should have a more defined map of the MW.

We might have to drastically increase the estimated mass of the MW.

Of course all the hype is on the big bang, but I am more interested in the local findings.

Especially our "black hole" and the central area.
 
Last edited:
Jan 27, 2020
243
85
680
Hayseed, both great points.

Hopefully, unlike Hubble, the Webb telescope will have no problematic optics or any other machine problems because at L2, one million miles away, they'll never get fixed leaving the $10 billion (total project cost) space telescope adrift in the aether.

I, too will enjoy seeing the center of the Milky Way with magnificent clarity and observing stars at the edge of creation.

Time, alone, will tell of success or failure.
Hartmann352
 

ASK THE COMMUNITY