The James Webb Space Telescope (JWST) will be a giant—its multilayered sun shield stretches 22 meters, nearly twice the length of the Hubble Space Telescope....[More]
ORBITAL ORIGAMI
The James Webb Space Telescope (JWST) will be a giant—its multilayered sun shield stretches 22 meters, nearly twice the length of the Hubble Space Telescope. In order to fit inside the aerodynamic payload capsule on top of an Ariane 5 heavy-lift rocket, both JWST's sun shield and 6.5-meter mirror will be meticulously folded—its planned deployment in space looks like nothing so much as a butterfly unfurling from its cocoon. The photograph above shows a full-scale model of JWST with telescope team members at the NASA Goddard Space Flight Center in Greenbelt, Md.
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NASA
MADE (TO BE) IN THE SHADE
JWST is an infrared observatory, designed to seek out small, faint objects—such as nearby exoplanets—by the heat they emit as well as extremely distant objects whose light has been stretched, or redshifted, from the visible or ultraviolet to longer infrared wavelengths....[More]
MADE (TO BE) IN THE SHADE
JWST is an infrared observatory, designed to seek out small, faint objects—such as nearby exoplanets—by the heat they emit as well as extremely distant objects whose light has been stretched, or redshifted, from the visible or ultraviolet to longer infrared wavelengths. To keep noise levels down, JWST must be insulated from the sun's infrared radiation. Its sun shield, composed of five layers of aluminized polymer film, ought to do the trick. At a February lecture in New York City, Northrop Grumman's Jon Arenberg called the shield "a very high-tech version of a potato chip bag." Arenberg said the shield has an SPF of 1.2 million: "For every 1.2 million watts incident, it radiates about one watt to the telescope." Above, a one third–scale model of a sun shield layer is stretched for testing.
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Nexolve
MIRROR, MIRROR
The telescope's mirror comprises 18 hexagonal segments, each 1.3 meters across. In the photograph [ above ] six mirror segments undergo testing at the NASA Marshall Space Flight Center in Huntsville, Ala....[More]
MIRROR, MIRROR
The telescope's mirror comprises 18 hexagonal segments, each 1.3 meters across. In the photograph [above] six mirror segments undergo testing at the NASA Marshall Space Flight Center in Huntsville, Ala. Altogether, the mirror's diameter will be 6.5 meters, giving it seven or eight times the light-collecting area of Hubble, which hosts a single 2.4-meter mirror. Nevertheless, JWST's mirror weighs about the same as Hubble's, because the hexagonal segments are made of lightweight beryllium, and the back of each mirror slab is etched away to the point of removing all extraneous material.
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NASA/MSFC/Emmett Givens
DEEP SPACE
JWST will operate at a second Lagrangian point, or L2, a location in space 1.5 million kilometers away where the gravity of the sun and that of Earth balance out to keep the spacecraft essentially stationary relative to Earth....[More]
DEEP SPACE
JWST will operate at a second Lagrangian point, or L2, a location in space 1.5 million kilometers away where the gravity of the sun and that of Earth balance out to keep the spacecraft essentially stationary relative to Earth. By looping around L2, JWST can keep its shield pointed at the sun while avoiding the shadow of Earth and the moon. The location is a popular destination for astronomical observatories; in 2009 the European Space Agency's Herschel and Planck spacecraft lifted off on separate missions based at L2.
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ESA
ONE SHOT TO GET IT RIGHT (MAYBE)
Hubble's life has been extended time and again through five servicing missions in which space shuttle astronauts have fixed faulty components, upgraded instrumentation and replaced batteries....[More]
ONE SHOT TO GET IT RIGHT (MAYBE)
Hubble's life has been extended time and again through five servicing missions in which space shuttle astronauts have fixed faulty components, upgraded instrumentation and replaced batteries. The first such mission [pictured] was an absolute necessity; Hubble's mirror was malformed, causing optical problems that crippled the telescope until astronauts could fix it. But no human has ever traveled as far as sun–Earth L2, so at the moment a servicing mission to JWST is out of the question. "It does inform us that it has to work," Arenberg said. It is imperative that the engineers "avoid a Hubble-like mistake, because we will have no chance to recover," Arenberg added.
Nevertheless, the designers have been instructed to study the hypothetical addition of a grapple point, which an as-yet undeveloped deep-space vehicle might use to dock with JWST, assuming the telescope survived long enough for such a mission to become possible. (The telescope's baseline mission is five years, but Arenberg expects that it will last much longer.) "If some astronaut who is in nursery school right now wants to go up there and fix it, they'd be able to," Arenberg said.
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NASA
FIRST LIGHT
The universe's first generation of stars , predicted to be superbright behemoths of hydrogen and helium, has yet to be directly observed by humankind, leaving blank a chapter in our understanding of the universe's evolution....[More]
FIRST LIGHT
The universe's first generation of stars, predicted to be superbright behemoths of hydrogen and helium, has yet to be directly observed by humankind, leaving blank a chapter in our understanding of the universe's evolution. JWST should change that. "We want to be able to detect the first stars and galaxies," Arenberg said. Looking more than 13 billion years across the universe to this population of early stars, which formed just hundreds of millions of years after the big bang, JWST will see the stars' intense ultraviolet light stretched into the infrared. To verify that it has indeed seen the first stars, the telescope must be sensitive enough to peer further back in time to the cosmic dark ages to confirm that there are no fainter objects in the background.
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NASA/WMAP Science Team
YES! Send me a free issue of Scientific American with no obligation to continue the subscription. If I like it, I will be billed for the one-year subscription.
Awe inspiring photos! Awhile ago, Jonathan Arenberg (of NGST) reported on efforts to perfect a technique on a laser desorption and thermal emission spectroscopic that could be used to detect and analyze the abundances of organic and inorganic compounds in the surfaces of Jupiters icy moons. Perhaps the time is soon!
"JWST will operate at a second Lagrangian point, or L2, a location in space 1.5 million kilometers away where the gravity of the sun and that of Earth balance out ..."
somehow this does not make sense according to the slide. Wouldn't Earth and Sun both be pulling in the same direction?
Why not make a hexagonal tube shaped (single mirror, near-orbit) space telescope that can be made larger by simply keep sending a new copy to orbit and attaching to others?
"somehow this does not make sense according to the slide. Wouldn't Earth and Sun both be pulling in the same direction?"
Yes, they bungled the description on that one. The earth and sun are both pulling in the direction of the sun, and the L2 point is the point where the net force results in a one-year orbital period, thus keeping the alignment of earth/sun/telescope constant.
13. elderlybloke
in reply to MCMalkemus07:29 PM 3/17/10
MCMalkemus- Your statement is false .
The small (very small ) deviation of the mirror from the designed shape, the problem was solved by installing a small correcting mirror into the optics. A very ingenious solution, and one that has made Hubble into the best optical telescope in the world.
Reflecting on view 6/6 if the distance between us and the big bang is 13.7 billion LY,can we add the 'distance in front' of us to get the total age of the visible universe? Please an answer to this. frankboase2@gmail.com
16. jtdwyer
in reply to elderlybloke09:33 AM 3/19/10
elderlybloke - Fortunately the Hubble was corrected on a space mission to lower Earth orbit - It has been a fantastic, revolutionary tool.
However, this satellite will be orbiting the Sun beyond the Moon's orbit of Earth. Any repair mission would be much more difficult. Hopefully they get this one right the first time.
I think you're right. The description the author gives is for L1. At L2 the orbital force of the telescope cancels out the combined gravitational force of the sun and earth (+moon, etc.)
plenum - According to Wikipedia, at east, all 5 Lagrangian points are stable positions for a small body in relation to two massive objects. In those positions the directional gravitational and centrifugal forces effectively cancel each other. Please see:
http://en.wikipedia.org/wiki/Lagrangian_point
I don't find a definition for 'orbital force'. Were referring to centrifugal forces?
How do we know we will be seeing " back to the first stars in the universe". We don't know that we have seen even close to the outer edge of the universe. Do we even know or believe there is an edge to the universe? But I agree, "wow the ultimate Webb Cam". Such images should be magnificent, it's hard to believe there could be better images than have come from Hubble?
I have a feeling that the JWST will make the most important discovery in the history of mankind - detecting a planet other than Earth that harbors life, and that too before 2020.
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22 Comments
Add CommentAwe inspiring photos! Awhile ago, Jonathan Arenberg (of NGST) reported on efforts to perfect a technique on a laser desorption and thermal emission spectroscopic that could be used to detect and analyze the abundances of organic and inorganic compounds in the surfaces of Jupiters icy moons. Perhaps the time is soon!
Reply | Report Abuse | Link to this"JWST will operate at a second Lagrangian point, or L2, a location in space 1.5 million kilometers away where the gravity of the sun and that of Earth balance out ..."
Reply | Report Abuse | Link to thissomehow this does not make sense according to the slide. Wouldn't Earth and Sun both be pulling in the same direction?
If the telescope operates at such a distance from Earth, how would mainainance be performed, such as was done on Hubble?
Reply | Report Abuse | Link to thisL2 can be a bit tricky to understand, until you remember that there are also centrifugal forces to consider. Wikipedia has a good explanation.
Reply | Report Abuse | Link to thisWhy not make a hexagonal tube shaped (single mirror, near-orbit) space telescope that can be made larger by simply keep sending a new copy to orbit and attaching to others?
Reply | Report Abuse | Link to thisAs long as they are employing more and more people im happy no what they build.
Reply | Report Abuse | Link to thisHopefully whoever built the Hubble won't be involved in this project, otherwise it is a near certitude that they will flub the mission: permanently.
Reply | Report Abuse | Link to this"somehow this does not make sense according to the slide. Wouldn't Earth and Sun both be pulling in the same direction?"
Reply | Report Abuse | Link to thisYes, they bungled the description on that one. The earth and sun are both pulling in the direction of the sun, and the L2 point is the point where the net force results in a one-year orbital period, thus keeping the alignment of earth/sun/telescope constant.
wow the ultimate Webb Cam
Reply | Report Abuse | Link to thisWow, the ultimate Webbcam
Reply | Report Abuse | Link to thisThe illustration correctly represents the L2 position. The Lagrangian points are nicely described by Wikipedia, as msadesign suggested earlier.
Reply | Report Abuse | Link to thisMaybe this can be most simply understood as a small body orbiting the enormous mass of the Sun, stabilized by the intermediate Earth.
The key is that the small body's orbital position is constant in relation to both of the larger masses.
Nice to see Herschel get a mention
Reply | Report Abuse | Link to thisMCMalkemus- Your statement is false .
Reply | Report Abuse | Link to thisThe small (very small ) deviation of the mirror from the designed shape, the problem was solved by installing a small correcting mirror into the optics.
A very ingenious solution, and one that has made Hubble into the best optical telescope in the world.
If I recall correctly (IIRC for you IM'ers) it was Kodak? that did the Hubble.
Reply | Report Abuse | Link to thisThey used to make film, too.
Reflecting on view 6/6 if the distance between us and the big bang is 13.7 billion LY,can we add the 'distance in front' of us to get the total age of the visible universe?
Reply | Report Abuse | Link to thisPlease an answer to this.
frankboase2@gmail.com
elderlybloke - Fortunately the Hubble was corrected on a space mission to lower Earth orbit - It has been a fantastic, revolutionary tool.
Reply | Report Abuse | Link to thisHowever, this satellite will be orbiting the Sun beyond the Moon's orbit of Earth. Any repair mission would be much more difficult. Hopefully they get this one right the first time.
I think you're right. The description the author gives is for L1. At L2 the orbital force of the telescope cancels out the combined gravitational force of the sun and earth (+moon, etc.)
Reply | Report Abuse | Link to thisplenum - According to Wikipedia, at east, all 5 Lagrangian points are stable positions for a small body in relation to two massive objects. In those positions the directional gravitational and centrifugal forces effectively cancel each other. Please see:
Reply | Report Abuse | Link to thishttp://en.wikipedia.org/wiki/Lagrangian_point
I don't find a definition for 'orbital force'. Were referring to centrifugal forces?
as telescopes probe deeper and deeper isn't it not logical to expect in a couple of decades to see Big Bang itself ?
Reply | Report Abuse | Link to thisHow do we know we will be seeing " back to the first stars in the universe". We don't know that we have seen even close to the outer edge of the universe. Do we even know or believe there is an edge to the universe? But I agree, "wow the ultimate Webb Cam". Such images should be magnificent, it's hard to believe there could be better images than have come from Hubble?
Reply | Report Abuse | Link to thisI have a feeling that the JWST will make the most important discovery in the history of mankind - detecting a planet other than Earth that harbors life, and that too before 2020.
Reply | Report Abuse | Link to thiswaiting for this launch!!!
Reply | Report Abuse | Link to this