Launched in 2021, the James Webb Space Telescope (often called JWST) is a large, near infrared and visible space telescope with 18 mirror segments in Earth's L2 point. Use for questions about the telescope.
Questions tagged [james-webb-telescope]
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Why doesn't James Webb have a larger supply of thruster propellant?
Reading Wikipedia's article on the James Webb telescope, I'm struck by the following information. I don't understand how it arose as an optimal and/or preferred mission choice.
So,JW is in an unstable orbit at Lagrange L2. Unlike many other…
Stilez
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Is there any point in space that the James Webb Space Telescope would be unable to image?
The James Webb Space Telescope has some very specific positioning requirements; the second Lagrange point and the heat shield positioning being at the top of my mind.
Do these constraints eliminate the possibility of pointing the telescope at any…
Cory Klein
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How common is it for spacecraft to have "selfie" capability?
According to ESA:
A sudden small power reduction was observed in a solar array of Sentinel-1A, orbiting at 700 km altitude, at 17:07 GMT on 23 August. Slight changes in the orientation and the orbit of the satellite were also measured at the same…
uhoh
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How do we know the precise position of the JWST?
How does NASA know the exact position of James Webb Space Telescope at a given time? NASA has to be able to issue the mid course correction burns.
Since they are now up to MCC2, how do they determine the exact time and force required to enter the L2…
andro
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JWST - Why unfurl before reaching L2?
I was wondering why the JWST did the unfurling of the sunshade, deployment of mirrors, before getting to its stable orbit at L2.
Does the relative motion of the moving parts not affect the orbit/path to L2, and so could it have been done at either…
BruceWayne
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Why is the speed of James Webb Space Telescope decreasing?
Can anybody explain why is the speed of Webb slowing down as it is moving away from earth?
Stars Tracker
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Why does the optical design of the Webb mirror have three different types of panel?
I read that there are A, B, and C type mirror segments on Webb. Why are there three types, and why are they distributed around the way they are?
I assume the segments have to overall form exact sections of a parabola in their respective positions,…
andro
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If the James Webb Space Telescope explodes, is there a backup?
With the launch of the JWST nearing, what happens in the worst case? Let's say the rocket explodes and everything is 100% lost.
Are there back-up copies? Is everything on it one-of-a-kind? Is there a duplicate sister telescope and a time table for…
Evan Carroll
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Could the James Webb Resolve Earth?
Hypothetically, if one were to point the James Webb at Earth:
Could it be focused in such a way that the entire Earth was in it's FOV, or is it too close?
If this were possible, what would be the smallest object that could be resolved in orbit?
If…
ScottishTapWater
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How does the JWST change focus when it goes from looking at a near subject to looking at a far subject? (Does it even change focus?)
After following the extensive steps in the process of aligning and phasing the optics and instruments of JWST... I now wonder if further focus adjustments would be made based on distance to subject. Perhaps that focus is already factored into the…
BradV
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Could you bounce a tennis ball off of the James Webb sunshield?
News articles keep referring to the James Webb Space Telescope's sunshield as "about the size of a tennis court", which raises the question: could it function as a tennis court? Or, more specifically, if you threw a tennis ball at it, would the…
Jeremy Friesner
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How much of the sky can the JWST see?
According to the JWST FAQ:
To turn and point at different objects in space, Webb uses six reaction wheels to rotate the observatory. The reaction wheels are basically flywheels, which store angular momentum. The effect of angular momentum is…
Hobbes
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Can any other telescopes see the James Webb Space Telescope?
The James Webb Space Telescope has no cameras mounted that look at itself. If a malfunction occurred on-board, would any other telescope be able to resolve it with sufficient clarity to provide useful images (assuming that any problem involved one…
DrMcCleod
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Can the JWST deployment steps be reverted?
I think, if something does not work (had not worked), or some improvisative solution is needed to handle an unexpected problem, then it would significantly improve the configuration freedom if the deployment steps could be reverted. For example, if…
peterh
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Why are the JWST secondary mirror support booms not painted black?
Based on the more recent of the Webb construction photos as well as the drawings in the deployment explorer, the JWST secondary mirror support booms look rather white, and even shiny. Won't they reflect stray light into the telescope from all…
dfeuer
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